University of Hertfordshire

By the same authors

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Original languageEnglish
Publication statusPublished - 14 Nov 2014
EventBASES Conference - Burton Upon Trent, United Kingdom
Duration: 25 Nov 201426 Nov 2014

Conference

ConferenceBASES Conference
CountryUnited Kingdom
CityBurton Upon Trent
Period25/11/1426/11/14

Abstract

Rowing requires coordination of the lower body, upper body and trunk and is useful for examining total-body responses to exercise. There may be issues of obtaining reliable technique for novice participants, hence difficulties interpreting physiological and biomechanics responses. Stroke length is used to assess reliability of performance during the drive phase (Ng et al., 2013, Journal of Applied Biomechanics, 29, 180–187). Maximising stroke length is considered important to effective technique, whilst decreasing stroke length could indicate fatigue. The purpose was to examine the reliability of stroke length during the drive phase of ergometer rowing across increasing intensities with participants of differing skill levels. Fourteen male unskilled (age 26 ± 4.8 years; mass 78.4 ± 9.5 kg; stature 1.78 ± 6.07 m) and seven male skilled (age 27.7 ± 4.8 years, mass 83.9 ± 7.2 kg, stature 1.83 ± 5.57 m) participants gave informed consent. Ethical approval was granted by the university research ethics committee. An 8-camera Vicon Nexus (OMG, Oxford) motion-capture system recorded displacement of the left-finger marker during the drive phase using a Concept IIc ergometer (Concept II, Morrisville, USA) for five intensities (50, 75, 100, 125 and 150 W). The positional data were filtered and stroke length was calculated using a custom written LabVIEW programme. Ten trials at each intensity were analysed for reliability and differences between intensity and skill. Normality and within-session reliability were considered acceptable across all intensities (Intra-class correlation coefficient [ICC]2,1: range 0.983–0.992). Stroke length increased with respect to intensity for all the participants, and skilled rowers displayed longer stroke lengths. A mixed factorial ANOVA showed statistical main effects for intensity, and skill level however was superseded by the interaction (F2.6,49.65 = 4.903, P < 0.01). Large effect sizes (range d = 2.5–3.7) were seen between skill and stroke length per intensity. The results indicated that the stroke length of novice and skilled rowers was reliable relative to increasing exercise intensities. Within-participant coefficient of variation suggests greater consistency for skilled participants (CV range: 0.6%–4.28% and 0.36%–1.23%, novice vs. skilled, respectively). Effect sizes indicated meaningful differences in stroke length between groups, suggesting a possible marker for technique. These results indicate that a consistent rowing stroke is achievable for skilled and unskilled rowers, suggesting a rowing ergometer is a useful and reliable tool to assess physiological responses, such as economy of exercise and biomechanical quantities such as kinematics and internal work.

Notes

© 2014 Taylor & Francis

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