s48 400
405
410
415
420
425
430
435
Day 1. Posters – Sport and Performance
my role within the team as the sole sports performance analyst, an autoethnographic approach was adopted. Following ethical approval, I maintained a self-reflective diary drawing on my thoughts, opinions and experiences during a 15-month period between April 2014 and June 2015. I conducted an inductive thematic content analysis on the recorded reflections whereby the phenomenon of trust emerged as a key theme. To explore the importance of trust, I engage with key theoretical concepts (Hoy and TschannenMoran, 1999, Journal of School Leadership, 9, 184–208; Day, 2009, Journal of Educational Administration, 47(6), 719–730; Sztompka, 2000, Trust: A sociological theory, Cambridge, UK: Cambridge University Press; Hardin, 2002, Trust and trustworthiness, New York: Russell Sage Foundation) and draw upon the key personality traits and characteristics identified for effective sport science practitioner to excel within their respected discipline (Partington and Orlick, 1987, The Sport Psychologist, 1, 309–317; Lubker et al., 2008, Journal of Sport Behaviour, 31(2), 147–165). Four essential components for establishing trust between myself, and the athletes and staff were identified: appearance and visibility, confidence, honesty and integrity, and self-care. Stronger athlete–coach–analyst relationships were established once each team member articulated the four components. Athletes and coaches became attuned to the importance of performance analysis and a greater utilisation of the discipline was observed within the team’s practice. Trust therefore must be established by a performance analyst between athletes and coaches in order to advance the provision of performance analysis within a high performance sport system.
D1.P44. Skeletal muscle oxidative capacity is greater in the dominant versus non-dominant forearms of rock climbers 440
SIMON FRYER1*, DAVID GILES2, INMACULADA GARRIDO3, KEERON STONE1 & VANESA ESPAÑA-ROMERO3 University of Gloucestershire; 2University of Derby; University of Cádiz, Spain *Corresponding author:
[email protected] @sifry37
time. It has been suggested that higher-level rock climbers have a greater skeletal muscle oxidative capacity in their dominant forearm (flexor digitorum profundus [FDP]) when compared to their lower-level counterparts (Fryer et al., 2015, Journal of Sport Sciences, 33, 518–526). However, rock climbing routes usually require relatively equal use of both forearms during an ascent. Therefore, the aim of this study was to assess the potential differences in skeletal muscle oxidative capacity between the nondominant and dominant FDP of expert rock climbers. Institutional ethical approval was granted prior to data collection. Twenty-eight rock climbers ranging in ability levels from French 6a – 9a (age = 34.7 years, s = 6.6; mass = 64 kg, s = 8.9; height = 171.1 cm, s = 8.8) were asked to refrain from caffeine and strenuous exercise for 24 h prior to testing. Participants were asked to lie in a supine position for 15 min of quiet rest. Near-infrared spectroscopy was used to assess skeletal tissue oxygenation responses during (3–5 min) and after (5 min) arterial occlusion at 220 mmHg (Hokanson rapid inflation cuff) in both the dominant and non-dominant FDP. After rapid cuff release, the mean time to half recovery (t½r) and time to full recovery (tFr), as determined by the increase in percentage tissue saturation, were significantly quicker (P < 0.05) in the dominant compared to the non-dominant FDP (t½r mean difference = 0.37 s, 95% CI: 1.64, 0.1 s; tFr mean difference = 25.11 s, 95% CI: 22.25, 2.39 s). The dominant t½r and tFr were 10.2% and 23.9% quicker compared to the non-dominant flexor, respectively. The results suggest that oxidative capacity is greater in the dominant forearm of expert rock climbers and as such rock climbing coaches, trainers and practitioners should consider focusing training on improving muscle performance in the non-dominant arm.
450
455
460
465
470
475
480
485
D1.P45. Muscle activity and triaxial accelerations during cross-country mountain biking and the effect of wheel diameter 490 HOWARD HURST1*, JONATHAN SINCLAIR1, STEPHEN ATKINS1, LEE RYLANDS2 & JOHN METCALFE1
1 3
445
Competitive rock climbing places a large physiological stress on the forearm flexors for prolonged periods of
1
University of Central Lancashire; 2University of Derby *Corresponding author:
[email protected] @Howard_Hurst
The physiological demands of cross-country mountain biking have been well reported over recent years (Lee
495
Day 1. Posters – Sport and Performance 500
505
510
515
520
525
530
535
540
545
et al., 2002, Journal of Sports Sciences, 20, 1001–1008; Stapelfeldt et al., 2004, International Journal of Sports Medicine, 25, 294–300; Prins et al., 2007, Journal of Sports Sciences, 25, 927–935). However, few studies have investigated muscle activity during mountain biking or how different bicycle designs may influence this activity. Therefore, the focus of this study was to investigate the influence of different mountain bike wheel diameters on muscle activity and muscle acceleration as an indicator of vibration. With institutional ethical approval, nine male trained mountain bikers (age = 34.7 ± 10.7 years; stature = 177.7 ± 5.6 cm; body mass = 73.2 ± 8.6 kg) participated in the study. Riders were required to perform one lap of a crosscountry course as fast as possible on a 26ʺ, 27.5ʺ and 29ʺ wheeled mountain bike. dsEMG (as a percentage of dynamic peak task, %DPT) and acceleration (RMS) were recorded for the whole lap and during specific ascent and descent phases at the gastrocnemius, vastus lateralis, biceps brachii and triceps brachii. Within participants one-way repeated measure ANOVAs were used to determine statistical differences between wheel sizes and between muscle groups. No significant main effects were found by wheel size for each of the four muscles for either sEMG or acceleration (RMS) during the whole lap for ascent and descent (P > .05). However, when data were analysed between muscle groups, significant differences were found between biceps brachii and triceps brachii (P < .05) for all wheel sizes and all phases of the laps with the exception of for the 26ʺ wheel during the descent. Mean sEMG for the biceps brachii overall was 1.78 ± 1.66, 1.17 ± 0.74 and 1.32 ± 0.69 %DPT, for the 26ʺ, 27.5ʺ and 29ʺ wheels, respectively. Overall mean sEMG for the triceps brachii was 3.61 ± 1.28, 3.58 ± 1.34 and 3.66 ± 1.07 %DPT, for the 26ʺ, 27.5ʺ and 29ʺ wheels, respectively. These findings indicate that wheel diameter had no influence on the attenuation of muscle activity or vibration during cross-country mountain biking on the particular course used. However, more effort was observed in the biceps brachii during descending on the 26ʺ wheel. This is possibly due to an increased need to manoeuvre the front wheel over obstacles, whereas the larger diameter wheels potentially rolled over obstacles more effectively.
D1.P46. The effect of wheel diameter on cross-country mountain bike performance 550
HOWARD HURST1*, JONATHAN SINCLAIR1, STEPHEN ATKINS1, LEE RYLANDS2 & JONATHAN METCALFE1
s49
1
University of Central Lancashire; 2University of Derby *Corresponding author:
[email protected] @Howard_Hurst
Currently, there are three wheel size standards used in mountain biking, 26ʺ, 27.5ʺ and 29ʺ diameter. Few studies have researched the influence of these wheel sizes on cross-country mountain biking performance. Macdermid et al. (2014, Journal of Biomechanics, 47, 1829–1837) did report significant improvements in velocity and power output when comparing 29ʺ wheels to 26ʺ, though no studies have yet looked at the 27.5ʺ wheel. Therefore, the aim of this research was to ascertain the effect of all three wheel sizes on mountain bike performance during a cross-country time trial. Following institutional ethical approval, nine male trained mountain bikers (age = 34.7 ± 10.7 years; stature = 177.7 ± 5.6 cm; body mass = 73.2 ± 8.6 kg) participated in the study. Riders were required to perform a single lap of a 3.48 km cross-country course as fast as possible on each of the 26ʺ, 27.5ʺ and 29ʺ wheeled bikes. Lap time (s), power output (W), cadence (revs · min−1) and velocity (km · h−1) were recorded for each lap. Within groups one-way repeated measures ANOVAs were used to determine significant differences between wheel sizes. No significant main effect was found for lap time (F(2,16) = .69; P > .05; ɳ2 = .08), with mean times being 916.11 ± 54.45 s, 923.78 ± 52.93 s and 904.22 ± 54.77 s for the 26ʺ, 27.5ʺ and 29ʺ wheels, respectively. No significant main effect was found for mean velocity (F(2,16) = .70; P > .05; ɳ2 = .08), with mean values of 13.72 ± .77 km · h−1, 13.61 ± .76 km · h−1 and 13.91 ± .84 km · h−1 for the 26ʺ, 27.5ʺ and 29ʺ wheels, respectively. No significant main effect was found for mean power output (F(2,16) = 2.98; P > .05; ɳ2 = .27), with mean values of 211.06 ± 28.16 W, 211.50 ± 31.71 W and 220.93 ± 30.43 W for the 26ʺ, 27.5ʺ and 29ʺ wheels. No significant main effect was also found for mean cadence (F(2,16) = 3.53; P > .05; ɳ2 = .31), with mean values of 65.37 ± 5.71 revs · min−1, 66.51 ± 6.81 revs · min−1 and 67.83 ± 5.79 revs · min−1 for the 26ʺ, 27.5ʺ and 29ʺ wheels. This study showed there were no significant gains from riding a larger diameter mountain bike wheel over a one lap time trial. However, if results for one lap were extrapolated over a full race, the 29ʺ wheel may provide a performance advantage.
D1.P47. Examining relative age effect in British Premier League football MARK JEFFREYS, JOSH CANN & ABBE BRADY*
555
560
565
570
575
580
585
590
595
600
