Cardiopulmonary Responses to Exercise in Swimmer Using a Swim Bench and a Leg-Kicking Ergometer

There are few studies on the relative cardiopulmonary demands of the arm-stroke and the leg-kicking action in swimmers, mainly because of the absence of a suitable dry-land ergometer. Therefore, the purpose of this study was to compare the cardiopulmonary responses to exercise using a swim bench and a leg-kicking ergometer. Twelve highly-traimed male swimmers with mean age of 20.3 ± 1.9 (yrs), stature 1.77 ± 0.04 (m) and body mass of 73.7 + 3.3 (kg) gave written informed consent and performed two separate incremental exercise tests on subsequent days. These tests used either a swim bench for assessment of arm-stroke or a specially designed front crawl leg-kicking ergometer. Oxygen consumption (VO₂), heart rate (HR) and exercise intensity were recorded throughout both exercise tests. Peak oxygen consumption (V0_2peak), peak heart rate (HRpeak) and peak exercise intensity (El_peak) were also recorded. Furthermore, the relationships between submaximal heart rate and exercise intensity (HR/EI) and between oxygen consumption and exercise intensity (VO₂/El) for arm or leg exercise were explored. Mean values for VO_2peak, HR_peak and El_peak for a arm-stroke and leg-kick respectively were; 3.22 ± 0.31 vs 3.76 ± 0.42 (l · min^-1; P = 0.02), 170 ± 3 vs 176 ± 3 (b · min^-1; P = 0.07) and 124.2 ± 9.4 vs 141.3 ± 12.7 (watts; P = 0.01).The mean VO₂peak and Elpeak for arm-stroke respresented 85 % and 88 % respectively of the same measures for leg-kick. The HR/EI and VO₂/El relationships were shown to be linear (at least r = 0.94, P<0.05 and r = 0.96; P<0.01 respectively) and the differences in the gradients and elevations of these relationships for arm-strokte vs leg-kick were significant (at least P<0.05; ANCOVA). These results show that highly-trained swimmers can achieve similar peak levels of oxygen consumption when using the arms or the legs. The ability to assess the cardiopulmonary responses to front-crawl arm-stroking and leg-kicking relative to exercise iintensity might be useful in understanding the importance of the arm and leg components of whole body metabolism in swimmers, especially during training programmes.

Front-crawl - arm-stroke - leg-kick - cardiopulmonary - dry-land ergometers