The effects of arm crank strategy on physiological responses and mechanical efficiency during submaximal exercise |
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| Authors: | Victoria L Goosey-Tolfrey Paul Sindall |
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| Institution: | 1. Institute of Biophysical and Clinical Research into Human Movement, Department of Exercise and Sport Science , Manchester Metropolitan University , Alsager, UK v.tolfrey@mmu.ac.uk;3. Institute of Biophysical and Clinical Research into Human Movement, Department of Exercise and Sport Science , Manchester Metropolitan University , Alsager, UK |
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| Abstract: | Abstract The purpose of this study was to compare submaximal physiological responses and indices of mechanical efficiency between asynchronous and synchronous arm ergometry. Thirteen wheelchair-dependent trained athletes performed eight steady-state incremental bouts of exercise (0 to 140 W), each lasting 4 min, using synchronous and asynchronous arm-cranking strategies. Physiological measures included oxygen uptake (Vdot]O2), heart rate, and blood lactate concentration. The power outputs corresponding to fixed whole blood lactate concentrations of 2.0 to 4.0 mmol · l?1 were calculated using linear interpolation. Mechanical efficiency indices – gross efficiency, net efficiency, and work efficiency – were also calculated. An analysis of variance with repeated measures was applied to determine the effect of crank mode on the physiological parameters. Oxygen uptake was on average 10% lower (P < 0.01), and both net efficiency (P < 0.01) and gross efficiency (P < 0.01) were higher, during the asynchronous strategy at both 60 and 80 W (gross efficiency: 16.9 ± 2.0% vs. 14.7 ± 2.4% and 17.5 ± 1.8% vs. 15.9 ± 2.6% at 60 and 80 W respectively). There were no differences in heart rate, blood lactate concentration or power output at either of the blood lactate reference points between the asynchronous and synchronous strategies (P > 0.05). In conclusion, test specificity is an important consideration. If a synchronous strategy is to be adopted, it is likely to result in lower efficiency than an asynchronous strategy. The exercise testing scenario may help dictate which method is ultimately chosen. |
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