Effects of High-Intensity Combined Training on Women over 65

Experimental Section Gerontology 2007;53:340–346 DOI: 10.1159/000104098

Received: March 20, 2007 Accepted: April 10, 2007 Published online: June 15, 2007

Effects of High-Intensity Combined Training on Women over 65 J.M. Cancela Carral Carlos Ayán Pérez University of Education and Sport Sciences, Pontevedra, Spain

Key Words Exercise High-intensity training Strength training Older women

Abstract Background: Many studies have sought to assess the effects of physical exercise on older people, but there is little scientific evidence concerning its effects on subjects’ quality of life and cognitive function. Besides, there is a need to know how well the elderly can tolerate combined exercise programs of great intensity and frequency, without risking their health. Objectives: To determine whether older people are able to do a high-intensity combined program of physical exercise, and to analyze its effects at a conditional, cognitive and functional level as well as on their quality of life. Methods: Sixty-two community-dwelling women older than 65 took part in a randomized trial, with subjects assigned to a combined program of aquatic exercise plus high-intensity strength training (group 1), or plus calisthenic training (group 2). Group 2 training consisted of several aerobic, mobility and flexibility exercises; group 1 training consisted of 7 exercises targeting the major muscle groups of the body, performed on exercise machines at an intensity of 75% of 1 repetition maximum. Both groups trained 5 days a week during 5 months. Quality of life, cognitive function, and functional level were assessed by means of validated questionnaires. Conditional evaluations included static and dynamic strength, balance, flexibility, and aerobic capacity. Results: No participant withdrew for adverse effects during the program or at the end. Both groups obtained a significant im-

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provement in their quality of life and cognitive function, as well as in their balance and flexibility level, whereas only group 1 improved their static and dynamic strength significantly. Conclusion: Older women can take part in high-frequency, high-intensity training programs with no risk to their health while experiencing improvements to their quality of life, cognitive function, degree of independence and physical fitness. Copyright © 2007 S. Karger AG, Basel

Introduction

Increased life expectancy has led to a global aging of the population, which has in turn given rise to increased medical attention and health expenses for senior citizens. Physical exercise has been shown to be a very effective nonpharmacological way of reducing these expenses, especially as patients get older [1]. Many studies have sought to assess the effects of physical exercise on older people, but there is little scientific evidence concerning its effects on subjects’ health-related quality of life (HRQoL) and cognitive function [2, 3]. Yet physicians obviously need to know the different types of recommendable exercises, as well as the determining aspects of volume, intensity, frequency and progression in order to be able to prescribe them safely to individuals [4]. Regarding the type of research carried out so far, some authors have stated the need for studies proposing exercise programs of over 3 months [5] to include exercises Carlos Ayán Pérez University of Health, Science and Sport, Campus A Xunqueira S7N ES–36005 Pontevedra (Spain) Tel. +34 986 801 700, Fax +34 986 801 701 E-Mail [email protected]

Group

October

November

December

January

February

March

April

May

G1

Exercises in water

Exercises in water1 + Strength training2

G2

Exercises in water

Exercises in water1 + Calisthenic exercises2

1 2

June

Tuesdays and Thursdays. Mondays, Wednesdays and Fridays.

Fig. 1. Proposed training program.

other than walking, or resistance and strength training, for such exercises are the most widely used among the elderly and the best studied [6, 7]. Furthermore, we have no knowledge of any study on how well the elderly can tolerate combined exercise programs of great intensity and frequency. The objective of this study is therefore twofold: to show that senior citizens are able to follow a combined 5-month program of 5 weekly sessions of water exercises and high-intensity strength training with no risk to their health, and then to analyze any possible effects of the program on their condition, cognitive ability, function and quality of life.

Methods Patients Sixty-two community-dwelling women with an average age of 68.4 8 3.4 years were selected at random from a group of 144 enrolled on a physical activity program based on aquatic exercise under the auspices of the Senior Citizens’ Physical and Sport Activities organized by the City Council of La Coruña. This group was chosen as they were already taking part in a systematic physical activity program (of 4 weeks), which allowed us to begin with a homogeneous sample as regards predisposition to physical exercise, and thus reduce the possible dropout rate. All the women were subjected to a medical examination and the study was approved by the Faculty of Medicine of La Coruña University. All of them fulfilled the predetermined selection criteria: 665 years of age, good cognitive function [Mini Mental State Examination (MMSE) score 622] and no serious medical condition, such as cancer, cardiovascular disorders or stroke. They all gave their informed written consent in accordance with the guidelines established by the University of Western Ontario’s Review Board for research involving human subjects [8]. Training Program The subjects were randomly assigned to two groups (n = 31 each): group 1 training consisted of water exercises combined with strength training and group 2 training combined water ex-

Effects of High-Intensity Combined Training

ercises and calisthenic exercises. All subjects attended all sessions of the 5-week program. At the beginning and end of the training period, its effects were measured through different tests. Figure 1 shows the design of the study. Exercises in Water. The 45-min sessions were based on other programs proposed for similar subjects [9]. Time-tabling varied over the 4 microcycles of the program. In the first, sessions consisted of 20 min of warming up (e.g. relaxed swimming, flexibility), 15 min of main exercises (6 of muscular resistance in the water and 9 of moving in different positions and continuous swimming) and 10 min of cooling down (breathing and relaxing). The fourth and last microcycle consisted of 10 min of warming up, 30 min of main exercises (10 of stamina in the water and 20 of moving in different positions and continuous swimming) and 5 min of cooling down (breathing and relaxing). Both groups attended these sessions twice a week in a standard pool at 24 ° C. Strength Training. Bodybuilding machines of variable resistance were used. In the first sessions, patients had to become accustomed to the machines. Sessions were divided into warming up (aerobic resistance and mobility of the joints), bodybuilding (strength training as such) and cooling down (stretching and breath control). Bodybuilding was carried out at an intensity of 75% of 1 repetition maximum in 3 sets of 10 repetitions, at an average speed and with a 5-min pause between sets. The training circuit comprised the following exercises in the order stated: (1) leg press, (2) vertical butterfly, (3) leg extension, (4) double arm curl, (5) forward shoulder press, (6) hip flexion, (7) lever seated rear lateral raise. Sessions were held in a standard gymnasium 3 times a week with the load adjusted at the end of each microcycle after a test with submaximal loads. Calisthenic Training. Sessions were designed according to the guidelines of the National Institute on Aging [10], lasted 45 min and were, in the first microcycle, divided as follows: 20 min of warming up (walking, joint movement), 15 min of main exercises (6 of muscular endurance without apparatus, including sit-ups and rotating the torso, and 9 of aerobic resistance) and 10 min of cooling down (flexibility and relaxing). This time-tabling varied for each microcycle, the main exercise time increasing, so in the fourth and last microcycle there were 10 min of warming up, 30 min of main exercises and 5 min of cooling down. The control group did the calisthenic exercises 3 times a week in a multipurpose room provided with mattresses, wall bars and measuring 30 ! 15 m.

Gerontology 2007;53:340–346

341

Table 1. Characteristics of the patients who completed the study

Measurements Effects were measured by submitting a group of 6 individuals to continual exercises for a week in order to standardize criteria for information gathering. The first test took place in the first week of February and the last one in the last week of June. Tests began with personal interviews based on questionnaires in this order: (1) perceived level of health, (2) social resource level, (3) cognitive capacity, (4) functional level. Physical examinations took place on the same day straight after the interviews in the Department of Physiotherapy (Morphological Assessments) and the subjects’ condition was later assessed at the Riazor municipal multipurpose indoor sports center. Quality of Life To assess any possible effects of the program on patients’ quality of life, the following questionnaires were used: Perceived Level of Health. To measure this, the Health Orientation Scale [11] was used, which is divided into 24 items in 5 categories (interest in health, health image concern, internal health locus of control, personal health consciousness and health-related anxiety). The maximum score in each category is 25, except for the last 2, which each carry 20 points. Level of Social Resources. We used the validated Spanish version by Grau et al. [12] of the Older Americans Resources and Services Multidimensional Functional Assessment Questionnaire Scale, which mainly gathers information on an elderly person’s family structure, friendship and visits, and gives a result on a scale from 0 to 6. Cognitive Function The Spanish version of the MMSE [13] was used. The MMSE is divided into two sections, the first of which requires vocal responses only and covers orientation, memory and attention. The second part tests the ability to name, follow verbal and written commands, write a sentence spontaneously and copy intersecting polygons. The top score is 30 points. Functional Level We used Montorio’s [14] validated Spanish version of the Instrumental Activities of Daily Living Scale, which measures physical and instrumental autonomy in different daily tasks, such as shopping, preparing meals, or ability to manage money. The final score is between 0 and 8. Condition Assessment The following assessments were made by means of tests specifically validated for elderly people: (1) maximum handgrip strength [15], measured by manual dynamometry, the patient standing with her arm straight and parallel to her side and her palm towards the thigh; (2) maximum extensive strength of the legs [16], using an adaptable dynamometric platform, on which the patient bends her knees 140°, so that the platform grip touches the middle of the quadriceps; the arms must be in pronation while holding the grips and the legs must be stretched progressively until the maximum possible force is applied for 2 s; (3) abdominal resistance strength [16], with the patient lying on her back with the knees bent 140º and the soles and head on the mattress, arms stretched down the sides; the point of each in-

342


Total subjects (n = 56)

Group 1 (n = 27)

Group 2 (n = 29)

Age, years Height, cm Weight, kg Body mass index

68.5083.40 155.0986.22 69.2789.38 28.8183.61

68.2983.49 154.9585.89 71.96810.34 29.9683.98

dex finger touches the edge of an adhesive tape placed at right angles to the mattress; the patient must bend the trunk and slide the fingers over the adhesive tape to the other side, repeating the movement 25 times per minute; the test finishes when the patient cannot go on, does not carry out the exercise properly or has completed 75 repetitions; (4) static balance: flamingo test [17]; (5) flexibility of the trunk: sit-and-reach test [18]; (6) eye-hand coordination: plate tapping test [19]; (7) aerobic capacity: walking 2,000 m as fast as possible [20]; (8) maximum heart rate: measured with a cardiotachometer during the cardiorespiratory test; (9) VO2max: estimated with the equation by Oja et al. [20]: VO2max = 184.9 – 4.65 (Oja’s test time) – 0.22 heart rate (HR) – 0.26 (age) – 1.05 body mass index (BMI). Statistical Analysis Statistical analysis was performed using SPSS for Windows version 13.0 (SPSS Inc.). Independent paired-samples t tests and 2 tests were used to compare baseline values between groups 1 and 2. To determine variables that might be significantly related to the dependent measures, we used independent paired-samples t tests, with the level of significance set at p ! 0.05.

Results

Subject Characteristics Of the original 62 volunteers, 6 (4 from group 1 and 2 from group 2) were absent more than the permitted number of times (20%), so their results were not analyzed. The patients’ characteristics are shown in table 1. None of the patients withdrew from the program or reported any lesion or problem related to the program. Each patient attended an average of 90 sessions. No statistically significant differences were found between the two groups regarding baseline scores. Quality of Life Differences were observed after the training period in the subscales of the Health Orientation Scale and the Older Americans Resources and Services Multidimensional Functional Assessment Questionnaire Scale. A Cancela Carral/Ayán Pérez

Table 2. Effects of the program on quality of life, degree of independence and cognitive function for both groups (scores before and after the program)

Group 1 before Interest in health Health image concern Internal locus Personal health consciousness Anxiety Cognitive ability (MMSE score) Social resources Functionality

Group 2 after

t

4.2080.604 4.3480.839 1.8580.659 1.8780.741 2.8980.830 3.9981.173 4.3280.964 4.6280.874 3.3380.869 2.7981.073 24.3983.372 27.0081.909 3.4580.791 4.1180.672 7.9880.681 7.9980.0956

p value

–0.306 –0.131 –2.021 –1.428 1.768 –2.414 –4.955 0.426

0.763 0.897 0.041* 0.173 0.045* 0.034* 0.023* 0.070

before

after

t

p value

4.3080.938 4.3280.631 –1.242 2.2880.905 2.2380.979 –0.137 3.9980.727 3.9980.653 –1.165 5.0080.954 4.5280.632 –0.828 3.1381.001 3.0180.844 1.236 22.0784.488 27.0782.323 –2.873 3.1580.708 4.1680.687 –5.292 7.3180.895 7.8880.202 –2.391

0.242 0.894 0.271 0.427 0.041* 0.021* 0.001* 0.040*

* p ≤ 0.05.

Table 3. Base rates for the condition tests before and after the program and percentage of improvements Group 1

Right hand press, kg Left hand press, kg Leg strength, kg Abdominal resistance strength number of repetitions Balance, number of attempts Trunk flexibility, cm Eye-hand coordination, s Time 2,000 m, min Heart rate, beats/min VO2max, mlkg–1min–1

Group 2

before

after

19.5885.74 18.7885.76 51.08827.55 55.03826.24 4.583.06 23.2187.43 19.9684.85 22.1281.95 117.85818.92 18.3985.85

t

p value

gains, %

before

after

t

22.1486.26 –0.380 20.7685.62 –0.503 61.10822.84 –4.645

0.039* 0.042* 0.001*

13.07 10.54 19.62

18.2185.08 17.7685.33 43.83818.04

0.320 18.3285.01 0.203 17.4885.36 45.72817.30 –1.970

61.71814.00 –1.858 0.637 3.4182.16 2.775 24.8287.24 2.918 19.2085.82 0.667 21.4881.91 2.635 107.85816.41 18.8086.00 –0.174

0.046* 0.035* 0.016* 0.712 0.517 0.022* 0.865

12.14 24.22 6.94 3.81 2.89 8.49 2.23

50.92825.08 50.89823.85 0.049 6.2284.50 5.2283.68 –0.209 1.526 23.1885.44 26.4787.59 1.619 18.7184.12 18.5283.83 22.0283.01 22.3983.02 –0.030 108.21819.82 106.78820.00 –0.273 0.670 17.5089.87 17.5889.81

p value 0.757 0.844 0.084 0.962 0.040* 0.036* 0.149 0.977 0.791 0.624

* p ≤ 0.05.

more thorough analysis (table 2) shows that group 1 has achieved a significant improvement in the internal locus of control (p = 0.04) and in the anxiety level (p = 0.04), while group 2 only improved significantly in the latter (p = 0.04). It should be pointed out that both groups improved significantly in the social resource category (p = 0.023 and p = 0.001, respectively). Cognitive Function The MMSE scores are shown in table 2. Both groups achieved a significant improvement in their cognitive capacity after the program (p = 0.03 and p = 0.02, respectively).


Functional Level After the program, only group 2 achieved any improvement (p = 0.04), although group 1 showed a positive tendency in this regard (table 2). General Condition Table 3 shows the influence of the program on all variables analyzed as a function of the type of training carried out. Group 1 shows significant improvements in right (p = 0.04) and left (p = 0.04) dynamometry, in leg strength (p = 0.001) and in abdominal strength (p = 0.04). Both groups improved significantly in balance and flexibility, while only group 1 achieved any significant reduction in heart rate (p = 0.02). Gerontology 2007;53:340–346

343

Discussion

To our knowledge, this is the first randomized study to propose training for elderly people with a frequency of 5 sessions per week and at a high intensity, at least concerning strength. In this regard, it should be stressed that high-intensity strength training usually implies elderly people performing 3 sets of 8 repetitions of different exercises on bodybuilding apparatus, targeting the major muscle groups of the upper and lower body at an intensity of 80% of their maximum, 3 days per week [21]. In our study, however, a slight reduction was made to the intensity of the exercise (75%) in order to increase the volume (3 sets of 10 repetitions) and fulfill goals set. Both during and after the program, no patients withdrew or reported lesions, which shows that people over 65 can take on high-intensity training with no risk to their health. Quality of life has been defined as how one perceives one’s state of physical and mental health over time [22]. After the program, those taking part noted an improvement in their perception of health, which implies an improvement in their quality of life. Moreover, the two groups reduced their anxiety level and widened their social horizons, both of which are directly related to quality of life. Now, there is scientific evidence directly relating regular physical exercise with psychosocial well-being and HRQoL in the elderly [22, 23], perhaps for neurophysiological reasons, such as the liberation of endorphins, or the effects of exercise at the constitutional level, i.e., functional improvements and greater self-efficacy, not forgetting the social implications of group exercise. The better results for group 1 may be due to the type of exercise, as high-intensity strength training has been shown to be more effective in the treatment of certain psychosocial aspects of HRQoL than low-intensity exercise [24]. In any event, not all aspects of HRQoL improved, which bears out the idea that strength training has a limited effect on the HRQoL of elderly women [22]. It should be pointed out that, despite the great training load, no negative effects were observed on HRQoL, such as pain, fatigue, disruption of social interactions or mood swings. By the end of the program, both groups had experienced an increase in their cognitive function, which is not surprising, for longitudinal studies have confirmed the hypothesis that physical exercise delays cognitive decline [25, 26]. Although cognitive improvement has traditionally been related with an increased blood flow to the brain caused by exercise which brings on enhanced oxygen344


ation and perhaps an increase in fibroblasts in the hippocampus [26], this usually occurs in aerobic conditions, which were not adhered to in our study. Nevertheless, Lachman et al. [5] achieved modest improvements in working memory in over 65-year-olds undergoing resistance training, and stated that the greater the intensity of the training, the greater the improvements, which our study confirms. A possible cause for these authors is the liberation of insulin-like growth factor 1, which would have a positive effect on the brain’s molecular structure. Although many studies have shown exercise to be effective in improving the physical condition of the elderly, its effects on the improvement of daily tasks, and therefore on functional autonomy, are not clear [7]. Analysis of the results of our study shows that only the group that underwent calisthenic training improved significantly in this regard, while the other group did not achieve more than a slight positive tendency. This was to be expected, for an increase in muscular strength in the elderly is known not to necessarily imply functional strength [27]. The improvement of group 2 could be due to the structure of the exercises, which concentrated on the movement of the joints and flexibility, perhaps more specifically related to daily tasks. In any event, it should be pointed out that the functional improvement was only borne out by the questionnaires, which are open to erroneous interpretations, especially when a population with a good level of health is involved. It may, therefore, have been advisable to include some kind of physical assessment of the functional level, so our study may be flawed in this regard. Regarding condition, both groups experienced a very noticeable, significant and similar improvement in both balance and flexibility. The improvement of group 1 in balance may be due to an increase in muscular strength in the quadriceps, a point which has been closely linked with the level of static balance [28, 29]. Nevertheless, other authors have not achieved any improvement in this regard, despite having used strength training of a very similar intensity to ours [30]. Furthermore, it has been shown that high-intensity strength training does not improve the ability to control the submaximal muscular contractions, which are involved in posture control [31]. Therefore, other factors must be considered in both groups’ improvement, such as combining two different kinds of training, which has been reported by some authors as very beneficial to balance [28]. On the other hand, it should be borne in mind that an improvement in balance is not necessarily accompanied by improvements in condition, but sometimes the sureness and self-confidence gained by an individual after taking part in an exCancela Carral/Ayán Pérez

ercise program may improve balance confidence, and with it performance in tests of this type [32], which would be especially true of group 2. As for the improvement in flexibility, both groups must have benefited from the stretching performed in the cool-down period of each session. Furthermore, it has been confirmed that high-intensity strength training (80% of maximum) can lead to significant improvements in flexibility, perhaps because during resistance training the range of mobility increases, as the exercises use the whole range of movements permitted by the joints, both agonistic and antagonistic muscles being involved [33]. It is interesting to note that although the questionnaires showed an improvement in functional level, no improvement was registered in either group’s walking speed, which was to be expected, especially for group 1, as this group experienced a significant improvement in the strength of their legs. However, it should be remembered that our patients already had a good level of strength and there is known to be a threshold beyond which an increase in strength does not imply any functional improvement [33]. Furthermore, the test used does not give an accurate measurement of walking speed but of aerobic capacity. It is remarkable that this aspect of condition should not have improved in either of the groups, despite group 1 showing a significant improvement in their maximum heart rate, which may be due to the high-intensity strength training itself, for similar programs have also altered heart rate significantly [34]. Improvements in muscular strength were only significant in group 1, so it may be assumed that they were due

to the high-intensity strength training, which is in agreement with the literature, for such training has been shown to be effective in this regard and to be tolerated by the elderly [35, 36]. Thus, for example, Nakamura et al. [37] achieved significant improvements in hand pressure strength in older people who followed a training program at 80% of their repetition maximum. On the other hand, the increase in the strength of leg extension in our sample (19.6%) is lower than that achieved by Taaffe et al. [38] (41.5%), despite the lower training intensities used in their study. The lesser improvement of our sample may be due to their higher initial level. In this regard, Galvao and Taaffe [21] suggested high-intensity strength training (3 sets of 8 repetitions) and achieved a more modest gain than in the study mentioned above (32%), although the initial strength levels in their sample were very similar to ours (53 kg). Their results were, nevertheless, better than ours, perhaps owing to the higher intensity and to the inclusion of a rest day between sessions, factors which may have enhanced the effects of the training. In conclusion, our results support the idea that senior citizens can take part in high-frequency, high-intensity training programs with no risk to their health while experiencing improvements to their quality of life, cognitive function, degree of independence and physical fitness as a result. In any event, the results of this study should be interpreted with some caution, for the sample was biased as we used a group of women who already routinely took physical exercise and were motivated, which may somehow limit possible applications of our findings.

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