Optimising Exercise Training in Peripheral Arterial

Sports Med 2004; 34 (14): 983-1003 0112-1642/04/0014-0983/$31.00/0

REVIEW ARTICLE

 2004 Adis Data Information BV. All rights reserved.

Optimising Exercise Training in Peripheral Arterial Disease Andrew C. Bulmer and Jeff S. Coombes School of Human Movement Studies, University of Queensland, St Lucia, Brisbane, Queensland, Australia

Contents Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1. Prevalence of Peripheral Arterial Disease (PAD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2. Exercise Training for Patients with PAD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1 Limitations of the Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1.1 Method of Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1.2 Exclusion Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2 Frequency of Training . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3 Duration of Training Sessions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4 Work to Rest Ratios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5 Total Programme Duration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.6 Training Volume . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.7 Training Intensity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.8 Progression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.9 Detraining and Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.10 Mode of Training . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.10.1 Resistance Training . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.10.2 Stair-Climbing Training . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.10.3 Pole-Striding Training . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.10.4 Arm and Leg Ergometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.10.5 Further Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3. Supervision Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4. Recommendations for Future Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5. Conclusions and Recommended Training Prescription . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Abstract

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Peripheral arterial disease (PAD) is an obstructive condition where the flow of blood through peripheral arteries is impeded. During periods of increased oxygen demand (e.g. during exercise), peripheral limb ischaemia occurs, resulting in the sensation of muscle pain termed ‘claudication’. As a result of claudication, subjects’ ability to exercise is greatly reduced affecting their quality of life. Although many treatment options for patients with PAD exist, exercise training is an effective and low-cost means of improving functional ability and quality of life. Currently, there are limited specific recommendations to assist the exercise prescription and programming of these individuals. This review summarises data from 28 exercise training studies conducted in patients with PAD and formulates recommendations based on their results. Exercise training for patients with PAD should involve three training sessions per week comprising 45 minutes of intermittent treadmill walking in a supervised environment for a time period of 20

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weeks or more. Encouragement and direction is given to further research aimed at investigating the effectiveness of training programmes in these patients.

Peripheral arterial disease (PAD) is characterised by the development of obstructive atherosclerotic plaques in the arteries of peripheral limbs. As these plaques grow, they reduce blood flow through to tissues distal to the obstruction. Reduced blood flow (ischaemia) to the muscles is accompanied by sensations of local muscle pain and this is increased during periods of increased oxygen consumption ˙ 2), such as during exercise. Limb pain upon (VO exertion is a symptom of PAD and is termed intermittent claudication (IC). As acute peripheral ischaemia causes claudication, patients with PAD endure a chronic reduction in ambulatory ability and quality of life.[1] Exercise training is established as an effective therapy for patients with PAD who experience IC; however, there are limited specific recommendations in the literature regarding exercise prescription and programming for these patients. This review will discuss the results of 28 studies (literature search concluded June, 2003) that have used exercise training in patients with PAD and will make recommendations based on an analysis of data from 22 of these studies. 1. Prevalence of Peripheral Arterial Disease (PAD) The prevalence of PAD has been assessed in numerous populations. The prevalence in Australian males aged 65 years and over was reported at 16% in 2002.[2] Investigations in other countries have found prevalence rates ranging from 3% to 12%.[3,4] The prevalence of PAD appears similar between sexes;[5] however, increases with age reaching its peak in persons >70 years of age.[6] As the greatest prevalence of this disease occurs in the elderly, the strain that PAD treatment will have on health services in the years to come is raising concern.[7,8] Such concerns highlight the importance of cost-effective treatment of this disease. 2. Exercise Training for Patients with PAD Many treatment strategies for PAD exist, ultimately aimed at improving functional ability and  2004 Adis Data Information BV. All rights reserved.

quality of life in diseased persons.[9] These treatments include pharmacotherapy,[10,11] surgery[12-14] and behaviour change.[8] Participation in exercise programmes has consistently shown a significant improvement in functional ability, with exercise training described as one of the cornerstones of treatment for patients with PAD.[15] Exercise training is generally viewed as an inexpensive, low-risk option compared with other more invasive therapies.[16] Recently, some novel methods improving walking ability in patients with PAD have emerged, including the application of exercise-induced ischaemic preconditioning[17] and intermittent foot compression.[18] Furthermore, combining different treatments such as surgery and exercise, and exercise with pharmacotherapy, appear effective in providing additional benefits to patients over the use of individual therapies.[13,19] Recently, a Cochrane Review supported the role exercise training has in treating the symptoms of PAD.[20] When combining the findings of several randomised, controlled exercise training trials, Leng et al.[20] concluded that exercise training was an effective method for improving walking ability in patients. However, this review did not attempt to devise an optimal exercise paradigm from the data. In 1995, Gardner and Poehlman[21] published a meta-analysis of training studies conducted in patients with PAD. Their recommendations appear to have formed the basis of exercise prescription for patients with PAD to date. They concluded that the most effective training programme included training sessions >30 minutes in duration, at least three times a week, over a period of 27 weeks or more. On the important topic of exercise intensity, they stated that the programme must include training to near maximal pain levels. Together, they believed that these variables resulted in an optimal training response, maximising the improvement in walking ability. Although these findings are useful to the exercise physiologist, several questions remain unanswered, particularly in regard to duration, frequency and type of exercise (continuous vs intermittent). Since Sports Med 2004; 34 (14)

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this review, to our knowledge, additional PAD training studies have been published.[7,11,14,17,18,22-30] This review, based on the results of 22 studies,[13,14,17,19,22-28,30-40] will present relationships between training frequency (figure 1), training session duration (figure 2), total training duration (figure 3) and training volume (figure 4) on improvement in pain-free and absolute walking ability. The effect of training intensity, training mode, degree of supervision and the location of training (e.g. gymnasium or home-based) will also be discussed. 2.1 Limitations of the Review

Improvement in walking ability (%)

Variation in methodology and data analysis techniques makes comparisons between PAD exercise training studies difficult. Before discussing the studies, a number of limitations should be mentioned. The major outcome variable for most of the trials was time or distance to pain-free and absolute walking ability. To simplify the presentation of data we present all results as a relative (percentage) change in walking ability. The validity of this comparison will be determined by the homogeneity of the study populations. Secondly, when discussing the optimisation of training prescription variables, the independent relationship of these variables to walking performance was investigated. Consequently, trends between individual prescription variables and descriptors of walking ability are presented, when ultimately one must consider all principles of exercise prescription within a greater context of training adaptation. Therefore, the relationships presented here are simplified and may lack some precision. Pain-free Absolute

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Fig. 2. The relationship between training session duration and improvement in pain-free and absolute walking ability (n = 22 studies). The dashed and solid lines represent the polynomial regression for improvements in pain-free and absolute walking ability, respectively.

Relative improvement in walking ability has been used to compare results irrespective of the assessment technique used to quantify walking ability (progressive or constant load treadmill testing). This assumes that improvements assessed via each method are comparable. This assumption is a limitation as one method describes functional improvement during steady-state aerobic exercise, while the other represents the improvements at a continually increasing workload. Evidence to support this notion has been presented by Hiatt et al.,[23] Langbein et al.[29] and Parker-Jones et al.,[25] where improvements in walking ability using constant load testing exceeded improvements assessed using incremental graded testing (see appendix). These findings would suggest that data recorded using different testing methods should be considered separately. This will become possible when more data are presented in future. Despite these limitations, clear trends are present within the data (see figures 1–4) and from these trends a recommended training prescription has been developed. 2.1.1 Method of Analysis

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Frequency of training (days/week)

Fig. 1. The relationship between frequency of training and improvement in pain-free and absolute walking ability (n = 22 studies). The dashed and solid lines represent the polynomial regression for improvements in pain-free and absolute walking ability, respectively.


Original data were abstracted from tables and abstracts within appropriate research publications (see section 2.1.2). These data were expressed either as metres or minutes/seconds walked before and after training. Percentage improvement in walking ability was calculated as follows: [(peak walking ability – baseline walking ability)/baseline walking ability] × 100. If original data were not available then quoted percentage improvement values were used.[17,30] Graphs were developed in the format of Sports Med 2004; 34 (14)

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surement of walking ability,[29,40] they were also excluded from the analysis. Finally, data from supervised studies that documented overall compliance as being 3 days/ week, improvements in pain-free walking and absolute walking ability tend to decrease, ranging from 24%[17] to 119%,[24] and 44%[17] to 99%,[24] respectively. Figure 1 suggests that 3 days/week represents the optimum training frequency for patients with PAD. This finding supports the American College Pain-free Absolute

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Training volume (minutes) Fig. 4. The relationship between training volume and improvement in pain-free and absolute walking ability (n = 22 studies). The dashed and solid lines represent the polynomial regression for improvements in pain-free and absolute walking ability, respectively.

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of Sports Medicine (ACSM)[43] recommendations for PAD patient training and those of Gardner and Poehlman[21] who suggested training must be completed 3 days or more per week before improvements in walking ability become statistically significant. As no research has specifically addressed this question, this would provide an interesting area of future study. 2.3 Duration of Training Sessions

It is unknown whether varying training session duration affects walking ability in patients with PAD. Gardner and Poehlman’s[21] meta-analysis presented a relationship between training session duration and walking ability. Their results indicated that programmes incorporating >30-minute training sessions were more likely to improve walking ability. However, training session duration was not found to be an independent predictor of improved walking ability. Training session duration has varied from 10[17] to 60 minutes,[23] with the majority using 60 minutes per session.[23,25,26,35,38] Some studies have used progressive training regimes that increase walking time from 15 to 60 minutes per session during 24 weeks of training.[28,37] Surprisingly, these studies reported similar results to training studies that use a constant training duration throughout[23,35] (see appendix). It is important to mention that the training session duration may not reflect the actual exercise time. Hiatt et al.[35] incorporated 5 minutes at the beginning and end of each 60-minute session to a warm up and cool down, reducing the effective training time of sessions to 50 minutes. More importantly, due to the nature of PAD patient impairment, walking exercise can only be sustained for short periods of time[44] before individuals are overcome by claudicating pain. Therefore, patients must exercise intermittently allowing the sensation of muscle pain to subside during rest periods. Approximately 5 minutes[25] is required for claudication pain to subside. Therefore, in 50 minutes of training, a patient may only complete three walking bouts approximating one-half of the training session duration.[35] Interestingly, the studies of Gardner et al.[28] and Izquierdo-Porrera et al.[37] standardised and presented actual exercise times in their methods and, therefore, present a more accurate association between the  2004 Adis Data Information BV. All rights reserved.

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training session duration and the resultant improvement in walking ability. Figure 2 describes the relationship between the duration of individual training sessions and improvement in pain-free walking and absolute walking ability. When training subjects for approximately 10 minutes per session, Capecchi et al.[17] reported improvements in pain-free walking and absolute walking ability in the range of 14–15% and 23–27%, respectively. Thirty-minute training sessions appeared to increase results with improvements in pain-free and absolute walking ability approximating 97%[14] to 276%,[36] and 91%[14] to 210%,[31] respectively. Finally, when 60-minute training sessions have been prescribed, results appear to plateau with improvements from 61%[22] to 209%[23] in pain-free walking and 38%[25] to 165%[35] in absolute walking ability. Figure 2 would suggest that training protocols adopting between 30- and 60-minute training sessions would optimise improvement in walking ability. As no original investigation has probed this question, there is a need for research in the area. 2.4 Work to Rest Ratios

To date, little mention of altering the work to rest ratios during training has been discussed in the literature. It is assumed that most published papers that train patients with PAD engage in intermittent training where patients walk, encounter claudication, stop to rest and once claudication pain subsides, resume walking. However, the duration of exercise and rest periods does not appear to be controlled within many of these publications. Indeed, altering the work to rest ratio during training may be one of the most important variables regarding exercise prescription for patients with PAD. One report would appear to have shed light on work to rest ratios inadvertently. While investigating the effect of exercise-induced ischaemic preconditioning, Capecchi et al.[17] controlled the duration of rest between four submaximal training bouts on a treadmill. Pain-free and maximal walking ability was quantified before and after these sessions. In one condition, patients were rested for 5 minutes between each submaximal effort and in another condition the patients’ rest period was 120 minutes. The results indicated that both training conditions imSports Med 2004; 34 (14)

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proved walking ability to a similar extent (see appendix). Walker et al.[7] also controlled the work to rest ratios (2 minutes of work with 2 minutes of rest) during arm and leg ergometry training. However, the purpose of this study was not to look at varying work to rest ratios during interval training, so they did not alter this variable between groups. A study manipulating the work to rest ratios during training, relative to the time to claudicating pain, is warranted. 2.5 Total Programme Duration

It is well known that adopting exercise training should be a life-long goal for almost all individuals; however, it would be important to determine the time-course of adaptations in patients with PAD due to exercise training. This knowledge would be helpful when giving specific advice to individuals as they commence a training programme, but few investigations have probed the time-course of training adaptation specifically. Perkins et al.[14] presented serial 3-month measurements of pain-free and maximal walking ability during a training programme. Their data suggest that a progressive increase in walking ability occurs, peaking at 15 months. Hiatt et al.[23] investigated the effect of walking training programmes that varied in total duration. Their results indicated a significant increase in walking ability when comparing a 12- and 24-week training programme. The American College of Sports Medicine[43] stipulate 12 weeks of training as being of minimal duration based on a small number of studies contradicting the findings of Gardner and Poehlman[21] who have suggested training be conducted for longer than 6 months. Serial measurements of pain-free and maximal walking ability during training can be found in other publications, but these results are quite variable as different studies have different resolution of measurement and different total programme durations. Therefore, we direct readers to figure 3, a graph representing the relationship between total programme duration and improvement in walking ability. The total duration of training varies somewhat within the literature from 1 day[17] to 6 years,[14] although the majority of investigations have trained subjects for 12–26 weeks.[21,25,26,32,33,37] Studies that have adopted training programmes ≤6 weeks in du 2004 Adis Data Information BV. All rights reserved.

ration have documented improvements in pain-free and absolute walking ability of 14%[17] to 119%,[24] and 23%[17] to 99%,[24] respectively. As total training duration increases to 17 weeks (4 months), improvement in walking increases with pain-free and absolute walking ability ranging from 70%[25] to 276%,[36] and 38%[25] to 165%,[35] respectively. Beyond 17 weeks of training, improvements in walking ability tend to plateau (see figure 3). Improvements in pain-free and absolute walking ability range from 88%[38] to 202%,[32] and 64%[37] to 210%[31] after 26 weeks of training, respectively. The data displayed in figure 3 would suggest that improvements in walking ability peak between 12 and 24 weeks of training. As few studies have monitored the improvement in walking ability over time, it is recommended that regular reassessment of maximal walking ability is undertaken and documented within future research. 2.6 Training Volume

In light of investigations adopting a multitude of various training frequencies and durations, perhaps a more appropriate variable to compare results between studies would be training volume. Training volume can be calculated using the following equation:[21] training volume = frequency (days per week) × session frequency (sessions per day) × session duration (minutes per session) × total duration (in weeks). As training volume increases from 0 to 2000 minutes, pain-free and absolute walking ability tend to increase (see figure 4). Beyond 2000 minutes of training, pain-free and absolute walking ability tend to decrease. As very few studies have prescribed >3000 minutes of training, this relationship should be interpreted with caution. Ideally, more results from studies adopting 3000 minutes or more of training would describe the association with greater accuracy. 2.7 Training Intensity

It is unknown whether manipulating training intensity alone can improve walking ability in patients with PAD. In Gardner and Poehlman’s[21] metaanalysis, they reported that walking ability did not improve unless patients were trained beyond their Sports Med 2004; 34 (14)


pain-free threshold, suggesting training to pain-free distances is not effective in improving walking ability. Recently published findings suggest this recommendation requires updating as improvements in walking ability are documented when patients train to pain-free thresholds.[17,30] It is difficult to systematically assess what effect training intensity has on walking ability as training intensity is: occasionally not documented;[14,29] quantified using subjective measurements of pain;[25,35] a percentage of maximal walking distance/time;[26,41] or expressed in metabolic equivalents.[35] Currently, the majority of research has trained subjects at an intensity that induces claudicating pain, presumably as muscle pain is associated with training adaptation. However, to our knowledge, no original research appears to support this notion. As all research publications train subjects to the point of claudication pain or beyond and few other descriptors of training intensity are documented (heart rate, ˙ 2, venous lactate) during training, it is difficult to VO compare results and determine the effectiveness of differing training intensities. Furthermore, as training and testing require patients to exercise to certain degrees of pain tolerance, this measure of intensity relies on subjective assessment and may contribute to the variability in walking performance. Perhaps ˙ 2, CO2 production the measurement of heart rate, VO and compounds that are associated with the development of muscle pain such as plasma/interstitial K+,[45] H+[46] and lactate[47] could aid in the description of training intensity in future. 2.8 Progression

Progression exists when the training demands placed upon the body result in overload and adaptation. Progression requires overload to occur intermittently throughout the training programme so that the stimulus to adapt continues, resulting in the training response to exercise. Progressive training paradigms appear to fall into two categories. The first incorporates progression in the form of increasing the duration of exercise within individual training sessions. An example includes assessing maximal walking time intermittently throughout training and re-prescribing training bout duration as a percentage of maximal walking ability.[22,24] This effectively increases the duration of individual walking  2004 Adis Data Information BV. All rights reserved.

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bouts. Unfortunately, some authors have not documented whether maximal walking ability was reassessed throughout training and, therefore, it is unknown whether they adopted this progressive component within their training.[13,25] The second form of progression involves increasing the intensity of training and increasing the duration of training sessions also. Gardner et al.[28] and Izquierdo-Porrera et al.[37] increased the intensity (percentage of maximal walking workload) and duration of walking at monthly intervals. Walking workloads began at 50% and increased to 80% within 6 months. Duration of total walking time increased 5 minutes per month from 15 to 40 minutes after 6 months of training. Their results demonstrate that improvements in pain-free walking are in the range of 106–177% and 64–80% in absolute walking ability. It is unknown whether Gardner et al.[28] and Izquierdo-Porrera et al.[37] reassessed maximal walking ability throughout training but it is assumed this occurred considering the substantial increase in walking ability reported. When comparing these results to those of the median for reviewed studies (119% and 83%), they appear similar and would suggest that the use of this type of progression does not afford additional improvements in walking ability over more simplistic progressive paradigms. 2.9 Detraining and Maintenance

Very little information is available on the occurrence of detraining in patients with PAD after training. Detraining was documented in a study published by Perkins et al.[14] who conducted a longterm training study over 6 years. After 24 weeks of training, pain-free walking ability increased 97% and absolute walking ability increased 91%. Subjects were required to continue dynamic leg training at home and ‘on a regular basis’ in the laboratory. However, after a further 5.5 years, walking performance had returned to baseline. The most likely explanation for this result is poor adherence to training.[14] Further studies specifically addressing detraining should be devised with greater resolution of measurement so that this phenomenon can be more accurately described. Gardner et al.[28] successfully prescribed a maintenance training programme in patients with PAD after 24 weeks of walking training. After this trainSports Med 2004; 34 (14)

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ing programme, intensity and duration of training sessions were maintained, but training frequency was reduced from 3 to 2 days/week. After a 52-week period of reduced training frequency, patients maintained the improvements in walking ability seen after the initial 24 weeks. After 52 weeks of maintenance, pain-free walking ability improved 12% and absolute walking ability did not change. 2.10 Mode of Training

Only a few research studies have compared the use of different training modes in improving walking ability in patients with PAD. The use of resistance,[1,23] stair-climbing,[25] pole-striding[29] and less specific modes of training including flexibility[11] and gymnastics[38] have been complemented with, or in place of, treadmill walking in an attempt to improve walking ability in patients with PAD. The effectiveness of each type of training appears to vary; however, few statistical comparisons analysing the effectiveness of walking training to other training modes have been made.

group and by 53% in the treadmill group. These data combined would suggest that treadmill training is more effective in improving pain-free and maximal walking ability than the prescribed resistance programme. Lundgren et al.[13] and Perkins et al.[14] also used dynamic resistance exercise to train their subjects; however, they did not describe the nature of the activity other than to state that supervised sessions lasted 30 minutes and were conducted 3 and 2 days/ week, respectively, for 26 weeks. Training in both studies was repeated at home suggesting that exercises could have incorporated walking and/or the use of leg weights and resistance bands. The authors presented increases in pain-free walking ability from 97–179% and increases in absolute walking ability of 91–151%. These results differ somewhat from the median pain-free walking and absolute walking results of reviewed studies, 119% and 83% respectively, suggesting that this particular dynamic exercise programme may be more effective in improving walking ability than treadmill training. 2.10.2 Stair-Climbing Training

2.10.1 Resistance Training

Resistance training prescribed by Hiatt et al.[23] required subjects to train for 60 minutes, three times a week, for 12 weeks. Subjects performed concentric contractions of five different muscle groups in the legs at a resistance that caused fatigue after six contractions. Muscles including the gastrocnemius, tibialis anterior, quadriceps femoris, hamstrings and gluteus maximus were trained in this manner. The resistance to muscle contraction was applied by attaching cuff weights to the appropriate location on the leg. Three sets of exercises were completed on each muscle of each leg in total. A six repetition maximum was assessed every 2 weeks and training intensity was altered accordingly by increasing the resistance. Walking ability was assessed using a graded treadmill test before and after 12 weeks of resistance training. The results were compared with those of another group who trained by walking on a treadmill for an identical training period. Resistance training did not improve pain-free walking ability in this group; however, treadmill-trained subjects improved their pain-free walking ability by 103%. Changes in maximal walking ability were different between groups, improving by 36% in the resistance  2004 Adis Data Information BV. All rights reserved.

Parker-Jones et al.[25] compared the efficacy of stair-climbing and treadmill training in improving stair-climbing and walking ability. Twelve subjects were randomly assigned to either walking or stairclimbing training 60 minutes per day, twice a week for 12 weeks. Before and after training, all subjects’ walking and stair-climbing ability was assessed using steady-state and graded protocols. Treadmilltrained subjects improved their pain-free walking ability by 38% and 132% on graded and steady-state treadmill tests, respectively. The stair-climbing trained subjects improved their pain-free walking ability by 18% and 25% on identical tests. Furthermore, only treadmill-trained subjects improved their absolute walking ability on the treadmill tests. These results suggest that specificity of training is important, with walking training providing the most effective means of improving walking ability. 2.10.3 Pole-Striding Training

Langbein et al.[29] reported improvements in walking ability in a group of patients with PAD after prescribing 24 weeks of pole-striding training. Absolute walking ability improved 51% using an incremental exercise assessment and 181% using a conSports Med 2004; 34 (14)


stant load assessment. These results are comparable with those found when training subjects on treadmills.[23,38] Replication of this study including a walking training group is required so that comparisons between training modes can be made. 2.10.4 Arm and Leg Ergometry

Similar to pole-striding training, no direct comparisons between ergometry and walking training have been made. Walker et al.[7] investigated the effect of upper- and lower-limb ergometry on walking ability and found that both forms of training improved pain-free and absolute walking ability to a similar extent. The improvements in pain-free and absolute walking ability approximated 120% and 50%, respectively. These results are in accordance with those obtained in walking training studies of Hiatt et al.[23] and Mannarino et al.[38] although appear less than the results of Patterson et al.[26] and Lundgren et al.[13] (see appendix). In summary, there is limited research comparing the efficacy of different training modes in improving walking ability in patients with PAD. Of those studies that have made direct comparisons, it would appear that walking training is the most effective training mode to improve walking ability. 2.10.5 Further Considerations

Exploring the use of different modes of exercise has become an important research topic for further reasons. Some elderly people are not able to, or are not comfortable with, exercising on treadmills.[44] Furthermore, the use of training modes other than walking could improve the adherence of subjects to training programmes by removing the discomfort of claudication during exercise. Recent studies have focused on the efficacy of training upper-limb muscle groups in improving walking ability, the results of which are discussed in section 2.10.4.[7,29] The findings by Walker et al.[7] imply that systemic training effects may provide significant benefits to these patients. If this is the case, exercise modes targeting muscles not in the lower limb could be effective in improving walking ability whilst sparing patients the discomfort of claudicating pain. Ischaemic preconditioning is a novel intervention where the blood flow to a tissue is intermittently obstructed resulting in temporary local ischaemia. Repeated cycles of ischaemia and reperfusion typify  2004 Adis Data Information BV. All rights reserved.

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ischaemic preconditioning protocols. These protocols are performed by occluding blood flow for 2[48] to 10 minutes.[49] The blood flow is then restored for similar time periods, typifying reperfusion. Periods of ischaemia and reperfusion are often repeated and can magnify the physiological responses to this stimulus.[50] Some authors have found that an intermittent ischaemic stimulus protects an organ/muscle from subsequent prolonged ischaemia and reperfusion injury.[49,50] More importantly, ischaemic preconditioning has been shown not only to protect local organs from ischaemia-reperfusion injury[49] but provides global/distant protection to other body organs that were not ischaemic[51] revealing beneficial systemic effects. Ischaemia and reperfusion would seem to occur in the vascular bed of claudicants calf muscles during and after exercise[52] and this stimulus has been suggested to evoke a preconditioning-like response in claudicants.[17] Therefore, this repetitive cycle of ischaemia and reperfusion, a result of intermittent walking training, could contribute to changes in muscle function at a local and systemic level via a similar mechanism. As claudicating exercise is a clinically relevant analogue of ischaemic preconditioning, further investigation of intermittent ischaemia and reperfusion could aid our understanding of the aetiology of PAD and has the potential to further improve walking ability in this population.[17] 3. Supervision Status Supervision can vary from non-supervised training at home to fully supervised training in a gymnasium. In studies that have directly investigated the effect of supervision, greater improvements in walking ability have been shown to coincide with greater degrees of supervision.[26] Some studies have adopted complete supervision of training sessions attempting to improve compliance of subjects.[35] Further variations in supervision include the use of a supervised period of training followed by an unsupervised period of training.[14,29] Langbein et al.[29] incorporated 4 weeks of unsupervised training into their programme and presented results that are similar to the median for reviewed studies. However, Perkins et al.[14] prescribed 5.5 years of mostly unsupervised training and as a result of poor subject compliance the initial improvements in walking Sports Med 2004; 34 (14)

992

ability were lost. Therefore, currently the efficacy of unsupervised training in patients with PAD is debatable. Patterson et al.[26] compared the effectiveness of a supervised laboratory-based training programme with a non-supervised home exercise training programme in improving walking ability. Subjects underwent either 12 weeks of supervised training consisting of three, 1-hour sessions per week or 12 weeks of home-based training exercising 3 days/ week for 20–40 minutes per session. The supervised training group improved their pain-free walking time by 195% and absolute walking time by 131%. In comparison, the home-based training group improved pain-free walking time by 83% and absolute walking time by 53%. After training, the differences between groups were statistically different indicating that supervised training was more effective in improving walking ability than home-based, unsupervised training. Although unsupervised training has been found to be ineffective in maintaining improved walking ability, the value of unsupervised training programmes should not be underestimated.[26,42] Patterson et al.[26] found that although supervised training was more effective than unsupervised training, participation in a highly structured unsupervised home-based training programme still provided significant improvements in walking ability. The home-based training programme, in this case, was supported by weekly health education lectures and professional guidance to promote subject adherence. Larsen and Lassen[42] also observed significant improvements in maximal walking ability after 26 weeks of daily unsupervised walking training. Unfortunately, the duration of walking sessions and the adherence of subjects to training was not documented; however, the intensity of walking was prescribed to the point of maximal pain tolerance. Their results provided early encouragement for researchers in the field presenting improvements in maximal walking performance of 186%. There is no doubt that unsupervised training has the potential to improve walking ability; however, the precise degree of improvement is currently a contentious discussion point. Therefore, more research probing this question is required to establish the efficacy of un 2004 Adis Data Information BV. All rights reserved.

Bulmer & Coombes

supervised training over supervised training, surgery and pharmacotherapy. 4. Recommendations for Future Research Perhaps the most important recommendation to emerge from this review is that more research independently exploring variations in training prescription (frequency, duration, intensity, mode and supervision) is required in an attempt to elucidate an exercise paradigm that maximises patient outcome. More general recommendations include the need for all published research to be controlled and randomised so that time-dependent alterations in PAD symptoms can be considered. Furthermore, the efficacy of different training modes should be examined in an attempt to cater for individuals who cannot or are unwilling to exercise on treadmills. In addition, training studies using muscle groups not involved in ambulation could be particularly interesting and applicable. The use of ischaemia/reperfusion protocols might also shed more light on preconditioning responses documented within the literature.[17] There is also a need to explore the effectiveness of unsupervised training programmes as current results are inconclusive. The formulation of an effective home-based, non-supervised training programme would reduce the cost of rehabilitation and thus provide additional benefits over other relatively expensive treatment methods including surgery and pharmacotherapy. Lastly, when comparing different modes of training (upperor lower-body; home- or laboratory-based) the total work completed by each respective training group should be identical so the results from each group can be compared. 5. Conclusions and Recommended Training Prescription Exercise training is recognised as an effective and low-cost means of improving functional ability in patients with PAD. Since the 1960s, numerous studies have identified training-induced performance effects in patients with PAD and have progressed from using traditional walking training[23,35] to resistance training,[1,23] stair climbing,[25] pole striding[29] and less specific forms of dynamic leg Sports Med 2004; 34 (14)

Study

Research design

Groups

Training

Treadmill test

Result

Conclusion

Cachovan et al.[22]

C

(A) PAD placebo control (n = not specified)

Supervised physical training programme

Constant load (3 km/h, 12% gradient)

61% ↑ in PFW distance (B)

Physical training improves walking ability

(B) PAD physical training (n = 23)

Gymnastics, 60 min/day, 5 d/wk, 4wk Including supervised treadmill training 2 × 2 cycles of claudicating exercise to 66% of AW distance

(A) PAD physical training (n = 23)[22]


(B) PAD physical training and pharmacotherapy (n = 10)

Stretching, knee bends, balancing exercises 30 min/d, 5 d/wk, 2wk Supervised treadmill training 30 min/, 5 d/wk, 2wk to 66% of AW distance Cycle ergometry 120 min/d, 5 d/wk, 2wk PGE1 administration 120 min/d, 7 d/wk, 2wk

Cachovan and Rogatti[11]

H/C

75% ↑ AW distance (B)


134% ↑ PFW distance (B)

Pharmacotherapy invokes an additive effect on walking performance when combined with physical training



Table AI. Summary of available studies in peripheral arterial disease training

97% ↑ AW distance (B) 76% ↑ in peak walking time (B) 108% ↑ peak workload (B) ˙ 2peak (B) 10% ↑ VO

↑ ↑ ↑ ↑ ↑

R

PAD treadmill training (n = 14)

Supervised treadmill walking (A) ~10 min × 4, 5 min rest (B) ~10 min × 4, 2h rest (C) ~10 min, twice daily for 1wk Walking to the onset of ischaemic pain

Graded (2.4–4.8 km/h, 0–5% gradient)

15% 23% 14% 27% 24%

PFW distance (A) AW distance (A) PFW distance (B) AW distance (B) PFW distance (C)

Ciuffetti et al.[30]

R

(A) PAD walking training (n = 15)


Constant load (2 km/h, 12% slope, 5 mins max.)

62% ↑ AW distance (A)

Multiple intermittent bouts of claudicating exercise can improve walking ability in PAD patients. Mechanism of ‘ischaemic preconditioning’ proposed Combined supervised/ unsupervised training programme improves max. walking ability

Continued next page

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Capecchi et al.[17]

994


Table AI. Contd Study

Creasy et al.[31]

Dahllof et al.[32]

Dahllof et al.[33]

Research design

R

R,C

R,C

Training

(B) PAD pharmacotherapy (n = 15)

Walking, marching, hopping and gymnastics 60 min/d, 2 d/wk, 13wk Unsupervised home exercise Walking 60 min/d, 7 d/wk, 12wk Exercise to the onset of ischaemic pain

(A) PAD physical training (n = 16)


(B) PAD surgery (n = 20)

30 min/d, 2 d/wk, 26wk ‘Regularly thereafter’ to 64wk Dynamic leg exercise including walking, running, static bicycling, ballgames Encouraged to repeat at home daily Beyond the appearance of ischaemic pain

(A) PAD control (n = 8)

Supervised physical training


30 min/d, 3 d/wk, 24wk Dynamic leg exercise Beyond the appearance of ischaemic pain




30 min/d, 3 d/wk, 17wk minimum Dynamic leg exercise Walking, running, dancing, ball games Beyond the appearance of ischaemic pain

Treadmill test

Result

Conclusion

Constant load (3 km/h, 10° gradient, 750m max.)

160% ↑ PFW distance (A: 26wk)

Dynamic leg training is effective in improving walking ability

210% ↑ AW distance (A: 26wk) 296% ↑ PFW distance (A: 39wk) 300% ↑ AW distance (A: 39wk)



Dynamic leg training improves walking ability


Constant load (4–6 km/h, 0% gradient)

150% ↑ in PFW time

Physical therapy improves PFW and AW ability in subjects with intermittent claudication

130% ↑ in AW time

Continued next page

Bulmer & Coombes

Sports Med 2004; 34 (14)

Groups

Study

Research design

Groups

Training

Treadmill test

Result

Conclusion

Delis et al.[18]

C

(A) PAD foot compression and aspirin (acetylsalicylic acid) and treadmill training (n = 25)

Intermittent foot compression

Constant load (3.8 km/h, 10% gradient)

146% ↑ PFW distance (A)

Foot compression, aspirin and unsupervised walking improves walking ability

(B) PAD aspirin and treadmill training (n = 12)

4 h/d, 20wk Unsupervised exercise 60 min/d, 20wk Aspirin (75 mg/d)

106% ↑ AW distance (A) 18% ↑ in resting ABI (A) 110% ↑ in post-exercise ABI (A) 31% ↑ in popliteal arterial flow (A) No changes in walking variables (B)

Ekroth et al.[34]

N/C

PAD physical training (n = 148)

Supervised physical training 30 min/d, 3 d/wk, 17wk minimum Walking, running, dancing and ball play Exercise beyond the appearance of claudicating pain

Constant load (4 km/h, 0% grade)

234% ↑ PFW distance 161% ↑ AW distance

Physical training improves walking performance in persons with intermittent claudication

Ernst and Matrai[39]

C


Treadmill training

Constant load (3 km/h, 13° gradient)

103% ↑ in PFW distance (B)

Treadmill training improves walking performance in persons with intermittent claudication

(B) PAD treadmill training (n = 20)

2 ×/d, 5 d/wk, 8wk Session duration not documented Walking to max. claudication pain



Table AI. Contd

121% ↑ in AW distance (B)

N/C

PAD treadmill training (n = 22)

Supervised treadmill training 3 bouts of exercise, 3 d/wk, 12wk Walking to 75% of max. walking time Session duration not documented

Constant load (1.6–3.2 km/h, 8–12% gradient)

479% ↑ in PFW time 582% ↑ in AW time 59% ↓ in ‘ischaemic window’ (reflection of recovery in limb blood pressure after exercise)

Treadmill training improves walking ability and reduces the magnitude of the ‘ischaemic window’ indicating functional improvement post training

Gardner et al.[28]

C,R


Supervised treadmill walking

Graded (3.2 km/h, 0% gradient, ↑ 2% every 2 min)


The first R, C trial to demonstrate that treadmill training improves walking ability

Continued next page

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Sports Med 2004; 34 (14)

Feinberg et al.[41]

996



Research design

Groups

Training

Treadmill test

Result

Conclusion Surveyed daily physical activity and max. calf blood flow in PAD patients


Hiatt et al.[35]

Hiatt et al.[23]

C,R

C,R

80% (B) 10% 10% 31% 18% Graded (3.2 km/h, 0% gradient, ↑ 3.5% every 3 min)

↑ max. claudication distance ↑ ↑ ↑ ↑

walking economy (B) 6 min walking distance (B) daily physical activity (B) max. calf blood flow (B)

165% ↑ PFW time (B)




60 min/d, 3 d/wk, 12wk Walking to ‘moderately severe’ claudication pain




60 min/d, 3 d/wk, 24wk

209% ↑ PFW time (24wk) [B]

(C) PAD strength training (n = 9)

Walking to moderate claudication pain Supervised strength training 60 min/d, 3 d/wk, 12wk

53% 79% 31% 13% 19%

(A) PAD placebo therapy (n = 6)

Supervised dynamic leg exercise

Treadmill training improves walking ability and max. calf blood flow in PAD patients

123% ↑ AW time (B) ˙ 2peak (B) 30% ↑ VO 38% ↑ max. calf blood flow (B) Graded (3.2 km/h, 0% gradient, ↑ 3.5% every 3 min)

Unspecified

103% ↑ PFW time (12wk) [B]

↑ ↑ ↑ ↑ ↑

Treadmill training improves walking ability in PAD patients. Supervised strength training does not have the same effect but is still beneficial

AW time (12wk) [B] AW time (24wk) [B] AW time (12wk) [C] ˙ 2peak (12wk) [B] VO ˙ 2peak (24wk) [B] VO


Early evidence that dynamic leg exercise improves walking ability

Continued next page

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Sports Med 2004; 34 (14)

Holm et al.[36]

C,R

15–40 min/d, 3 d/wk, 26wk 50–80% of max. workload Followed by supervised walking 40 min/day, 2 d/wk, 26–78wk 80% of max. workload Walking to near max. claudication pain

Study

IzquierdoPorrera et al.[37]

Langbein et al.[29]

Larsen and Lassen[42]

C

C,R

C,R

R

Groups

Training

Treadmill test

Result


30 min/d, 3 d/wk, 17wk Training beyond the appearance of ischaemic pain




15–40 min/day, 3 d/wk, 24wk 50–80% of max. workload Walking beyond the pain-free threshold


Supervised pole-striding training

Graded (3 km/h, 0% gradient, ↑ 0.5% every 30 sec. After 6 min speed was ↑ 0.32 km/h every 3 min)

51% ↑ AW time (B: graded protocol)

(B) PAD pole-striding training (n = 27)

Interval training at various intensities 3 d/wk for 4wk + 2 d/wk for 8wk + 1 d/wk for 4wk + Biweekly for 2wk + Unsupervised for 4wk (total 24wk)

Constant load (2.9 km/h, 12%)

181% ↑ AW time (B: constant load) ˙ 2peak (B) 13% ↑ in VO


Unsupervised walking training

Constant load (4.6 km/h, 0, 8 or 16% gradient)

186% ↑ AW time (B)

(B) PAD walking training (n = 7)

Daily for 26wk Walking beyond pain-free threshold



Conclusion


Graded (3.2 km/h, 0% gradient, ↑ 2% every 2 min)


Progressive treadmill training significantly improves walking ability ˙ 2peak in PAD and VO patients

64% ↑ AW time (B) ˙ 2peak (B) 7% ↑ VO

Pole-striding training is an effective method of improving walking ability and increasing ˙ 2peak in subjects VO with PAD

Daily unsupervised walking training results in improved walking ability

No change in max. muscle blood flow (B) Constant load (4 km/h, 0% gradient)


Dynamic leg exercise improves walking ability and max. calf blood flow in patients with IC

Continued next page

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Sports Med 2004; 34 (14)

Lundgren et al.[13]

Research design



Table AI. Contd

998



Research design

Groups

Training

Treadmill test

Result

(B) PAD reconstructive surgery and physical training (n = 25)



(C) PAD reconstructive surgery only (n = 25)

Dynamic leg exercise beyond the appearance of leg pain

18% ↑ max. calf blood flow (A)

Conclusion

699% ↑ PFW distance (B) 263% ↑ AW distance (B) 65% ↑ max. calf blood flow (B) Mannarino et al.[38]

Mannarino et al.[19]

C

R

Constant load (2 km/h, 12% gradient, 5 min max.)



(B) PAD walking training (n = 8)

2 d/wk, 26wk Marching, hopping, jogging and gymnastics + Unsupervised walking training 60 min/d, 2 d/wk, 24wk Progressive 1500–2000 m/h Walking to onset of claudication

(A) PAD exercise training (n = 10)


(B) PAD exercise programme, dipyridamole and aspirin (n = 10)

2 d/wk, 26wk

86% ↑ in max. walking time (A)

(C) PAD dipyridamole and aspirin only (n = 10)

Marching, hopping, jogging and gymnastics + Unsupervised walking training 60 min/d, 2 d/wk, 24wk progressive 1500–2000 m/h Walking to onset of claudication

120% ↑ in PFW time (B) 105% ↑ in max. walking time (B)

Combined supervised/ non-supervised walking training can improve treadmill walking performance

67% ↑ max. walking time (B) No significant change in performance (A)

Constant load (2 km/h, 12% gradient, 5 min max.)

89% ↑ in PFW time (A)

Walking training can be combined with pharmaceutical treatment to enhance walking performance

Continued next page

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Sports Med 2004; 34 (14)


Study

Research design

Groups

Training

Treadmill test

Result

Conclusion

ParkerJones et al.[25]

R

(A) PAD treadmill training (n = 6)

Supervised treadmill/stair climbing training

Treadmill graded (3.2 km/h, 0% gradient, ↑ 2% every 2 min)

70% ↑ in PFW time (A: progressive exercise test)

Treadmill and stairclimbing training improves max. walking and stair-climbing time on these apparatus. Treadmill training can improve stair-climbing performance and visaversa

(B) PAD stair climbing (n = 6)

60 min/d, 2 d/wk, 12wk Walking to ‘severe’ claudication pain Unsupervised walking exercise 60 min/d, 3 d/wk, 12wk Walking to ‘severe’ claudication pain

Treadmill constant load (3.2 km/h, variable gradient) Stairmaster graded (20cm step, 12 steps/min ↑ 4 steps/min every 2 min)

38% ↑ in AW time (A: progressive exercise test) 132% ↑ in PFW time (A: steady-state exercise test) 100% ↑ in AW time (A: steady-state exercise test) 44% ↓ in pain relief time (A)

(A) PAD supervised exercise programme (n = 27)

Supervised exercise programme

Graded (1.6–4 km/h, 5–10% gradient)

195% ↑ in PFW time (A)

(B) PAD home-based exercise programme (n = 28)

60 min/d, 3 d/wk, 12wk Treadmill walking Exercise to 75% of max. walking time + arm and leg ergometry Home exercise programme 20–40 min walking, 3 d/wk, 12wk Weekly health lecture (both groups)

(A) PAD resistance exercise (n = 26)

Supervised exercise programme

Patterson et al.[26]

Perkins et al.[14]

R

R



Table AI. Contd

Supervised exercise training is more effective in improving walking ability than home-based training

131% ↑ in AW time (A) 83% ↑ in PFW time (B) 53% ↑ in AW time (B) ↑ in perceived physical function (A,B) ↑ in bodily pain subscale (A,B) ↑ in perceived walking ability (A,B) Constant load (3 km/h, 10% gradient)

97% ↑ in PFW distance (A: 26wk)

Continued next page

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Participation in exercise training improves walking ability in PAD patients. Gains in walking ability are lost after 6y possibly due to reduced exercise adherence

1000



Research design

Regensteiner C,R et al.[1]

Scheffler et al.[24]

R

Training

Treadmill test

Result

(B) PAD angioplasty (n = 30)

30 min/d, 2 d/wk, 26wk Progressive dynamic leg exercise then on a ‘regular’ basis, 26–312wk Progressive dynamic leg exercise + advised to perform the same exercises at home regularly





↑ well-being score (C: 12wk)

(C) PAD strength training (n = 9)

Walking to claudication pain Supervised strength training 60 min/d, 3 d/wk, 12wk Six muscle groups of each leg

↑ in reported physical activity (B: 12, 24wk) ↑ ability to walk distances (B: 24wk) ↑ walking speed (C: 12wk) ↑ stair-climbing ability (C: 12wk)



(B) PAD physical training and IV pharmacotherapy (pentoxifylline [n = 15])

Twice daily, 5 d/wk, 4wk

(C) PAD physical training and IV pharmacotherapy (PGE1 [n = 14])

30 min group exercise, ball games, relaxation exercises + 30 min treadmill walking 3 km/h, 5% gradient, five cycles Walking to 66% of pain-free distance

Conclusion

91% ↑ in AW distance (A: 26wk) 14% ↑ in AW distance (A: 312wk)

Graded (3.2 km/h, 0% gradient, ↑ 3.5% every 3 min)


↑ bouts of exercise per h (B: 12, 24wk)


Physical training not only improves muscle function but perceived functional ability and well-being scores

Physical training significantly improves walking ability over 4wk


Continued next page

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Sports Med 2004; 34 (14)

Groups

Study

Research design

Groups

Training

Treadmill test

Result

Conclusion

Taft et al.[12]

C,R


Supervised walking training

Graded (0–12% gradient). Speed not documented

No change in AW ability (B)

Invasive therapy improved functional outcome in PAD patients. Exercise training did not; however, this is most likely due to poor patient compliance

(B) PAD exercise training (n = 73)


(C) PAD surgery (n = 76)

Training intensity not documented Followed by 30 min/day, 2 day/wk, 26wk (49% patient compliance to the first 6mo of training)


Supervised exercise training

(B) PAD exercise training (n = 22)


(C) PAD angioplasty (n = 28)

Active and passive leg exercises To maximum claudication pain Unsupervised exercise training 45 min/d, 7 d/wk, 52wk Daily 1.6km (1-mile) walks


Supervised leg-cranking exercise

(B) PAD upper-limb training (n = 26)


↑ max. leg power (B,C)

(C) PAD lower-limb training (n = 26)

Supervised arm-cranking exercise 20 min/d, 2 d/wk, 6wk

122% ↑ PFW distance (B) 47% ↑ AW distance (B) 93% ↑ PFW distance (C) 50% ↑ AW distance (C)

Gelin et al.[27] (companion studies)

Tisi et al.[40]

Walker et al.[7]

C,R

C,R

25% ↑ in AW distance (C)




Table AI. Contd

60% ↑ in PFW distance (B: 52wk)

69% ↑ in max. walking distance (B: 52wk)

Graded shuttle test (3km, ↑ 0.5 km/h every min)

↑ max. arm power (B,C)

Both upper- and lowerlimb training can enhance lower-limb walking ability in PAD patients

1001

Sports Med 2004; 34 (14)

ABI = Ankle, Brachial Index; AW = absolute walking; C = controlled; H/C = historically controlled; IC = intermittent claudication; IV = intravenous; max = maximal; N/C = not ˙ 2peak = peak oxygen consumption; ↑ indicates increase; ↓ controlled; PAD = peripheral arterial disease; PFW = pain-free walking; PGE1 = prostaglandin E1; R = randomised; VO indicates decrease.

1002

Bulmer & Coombes

exercise.[11,38] When combining the results from 22 training studies (excluding those studies yielding control data only[27,39,40]) the median improvement in pain-free walking ability equalled 119%[24] with a range of 14%[17] to 276%.[36] The median improvement in absolute walking ability equalled 83%[19,28] with a range of 23%[17] to 210%.[31] We have analysed the data from these studies and recommend that patients with PAD should partake in supervised treadmill walking 3 days/week for 45 minutes each session. The training should be intermittent with intensity at the pain-free threshold. Physiological benefits are optimised at approximately 20 weeks of training. More research needs to be conducted investigating the optimising of work : rest ratios, the rate of progression and different modes of exercise. Acknowledgements Andrew Bulmer, who is a 2001 Centenary Scholarship recipient, would like to acknowledge the generous financial assistance of the Foundation for Young Australians and the Australian Commonwealth Government. The authors have no conflicts of interest that are directly relevant to the content of this review.

Appendix See table A1. References 1. Regensteiner JG, Steiner JF, Hiatt WR. Exercise training improves functional status in patients with peripheral arterial disease. J Vasc Surg 1996; 23 (1): 104-15 2. Fowler B, Jamrozik K, Norman P, et al. Prevalence of peripheral arterial disease: persistence of excess risk in former smokers. Aust N Z J Public Health 2002; 26 (3): 219-24 3. Fowkes FGR. Epidemiological research on peripheral vascular disease. J Clin Epidemiology 2001; 54: 863-8 4. Novo S. Classification, epidemiology, risk factors, and natural history of peripheral arterial disease. Diabetes Obes Metab 2002; 4: S1-6 5. Hirsch AT, Criqui MH, Treat-Jacobson D, et al. Peripheral arterial disease detection awareness and treatment in primary care. JAMA 2001; 286 (11): 1317-24 6. Dormandy JA, Rutherford RB. Management of peripheral arterial disease (PAD). TASC Working Group. TransAtlantic Inter-Society Concensus (TASC). J Vasc Surg 2000; 31 (1 Pt 2): S1-S296 7. Walker RD, Nawaz S, Wilkinson CH, et al. Influence of upperand lower-limb exercise training on cardiovascular function and walking distances in patients with intermittent claudication. J Vasc Surg 2000; 31: 662-9 8. Lewis CM. Peripheral arterial disease of the lower extremity. J Cardiovasc Nurs 2001; 15 (4): 45-63 9. Regensteiner JG, Hiatt WR. Current medical therapies for patients with peripheral arterial disease: a critical review. Am J Med 2002; 112: 49-57


10. Smith JAM. Measuring treatment effects of cilostazol on clinical trial endpoints in patients with intermittent claudication. Clin Cardiol 2002; 25: 91-4 11. Cachovan M, Rogatti W. Improvement of peripheral and cardiopulmonary performance after a short-term exercise program with additive prostaglandin E1. Angiology 2001; 52 (6): 381-91 12. Taft C, Karlsson J, Gelin J, et al. Treatment efficacy of intermittent claudication by invasive therapy, supervised physical exercise training compared to no treatment in unselected randomised patients II: one-year results of health-related quality of life. Eur J Vasc Endovasc Surg 2001; 22: 114-23 13. Lundgren F, Dahllof A-G, Lundholm K, et al. Intermittent claudication: surgical reconstruction or physical training? A prospective randomised trial for treatment efficiency. Ann Surg 1989; 209 (2): 346-55 14. Perkins JM, Collin J, Creasy TS, et al. Exercise training versus angioplasty for stable claudication: long and medium term results of a prospective, randomised trial. Eur J Vasc Endovasc Surg 1996; 11: 409-13 15. Christman SK, Ahijevych K, Buckworth J. Exercise training and smoking cessation as the cornerstones of managing claudication. J Cardiovasc Nurs 2001; 15 (4): 64-77 16. de Vries SO, Visser K, de Vries JA, et al. Intermittent claudication: cost-effectiveness of revascularisation versus exercise therapy. Radiology 2002; 222 (1): 25-36 17. Capecchi PL, Pasini FL, Cati G, et al. Experimental model of short-time exercise-induced preconditioning in POAD patients. Angiology 1997; 48 (6): 469-80 18. Delis KT, Nicolaides AN, Wolfe JHN, et al. Improving walking ability and ankle brachial pressure indices in symptomatic peripheral vascular disease with intermittent pneumatic foot compression: a prospective controlled study with one-year follow up. J Vasc Surg 2000; 31: 650-61 19. Mannarino E, Pasqualini L, Innocente S, et al. Physical training and antiplatelet treatment in stage II peripheral arterial occlusive disease: alone or combined? Angiology 1991; 42 (7): 513-21 20. Leng GC, Fowler B, Ernst E. Exercise for intermittent claudication [Cochrane Review]. In: The Cochrane Library, issue 3, 2004 Available from URL: http://www.update-software.com/ abstracts/AB000333.htm [Accessed 2004 Oct 5] 21. Gardner AW, Poehlman ET. Exercise rehabilitation programs for the treatment of claudication pain: a meta-analysis. JAMA 1995; 274 (12): 975-80 22. Cachovan M, Scheffler P, Gruss J, et al. The effectiveness of standardized exercise training in intermittent claudication. Wien Klin Wochenschr 1994; 106 (16): 517-20 23. Hiatt WR, Wolfel EE, Meier RH, et al. Superiority of treadmill walking exercise versus strength training for patients with peripheral arterial disease: implication for the mechanism of the training response. Circulation 1994; 90: 1866-74 24. Scheffler P, de le Hamette D, Gross J, et al. Intensive vascular training in stage IIb of peripheral arterial occlusive disease: the additive effects of intravenous prostaglandin E1 or intravenous pentoxifylline during training. Circulation 1994; 90: 818-22 25. Parker-Jones P, Skinner JS, Smith LK, et al. Functional improvements following stairmaster vs treadmill exercise training for patients with intermittent claudication. J Cardiopulm Rehabil 1996; 16: 47-55 26. Patterson RB, Pinto B, Marcus B, et al. Value of a supervised exercise program for the therapy of arterial claudication. J Vasc Surg 1997; 25 (2): 312-9 27. Gelin J, Jivegard L, Taft C, et al. Treatment efficacy of intermittent claudication by surgical intervention, supervised physical exercise training compared to no treatment in unselected randomised patients 1: one year results of functional and

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Correspondence and offprints: Dr Jeff S. Coombes, School of Human Movement Studies, University of Queensland, Room 535, Connell Building, St Lucia, Brisbane, QLD 4072, Australia. E-mail: [email protected]

Sports Med 2004; 34 (14)