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Infraclass variations of cardiorespiratory responses to cardiopulmonary exercise testing among elite paracyclists with the same official functional limitations
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Edité par CCSD ; Elsevier/French Society of Cardiology -
International audience. IntroductionPara-cycling classification is based on a score point that is used to include athletes suffering from different pathologies but having comparable multiple functional impairments in the same race category. Hence, C3 class brings together athletes who are able to use a standard bicycle and presented, for example, a single above elbow amputation (AK) or moderate neurological disorders (ND, spasticity grade 2 lower limb), without regard to effect of the AK compared to ND on the maximal oxygen uptake (VO2max). However, VO2max and Anaerobic threshold (Anth) are recognized as two main determinants of cycling performance. It has previously reported an adverse AK effect on VO2max and exercise capacity due to cardiac and respiratory muscular systems’ ability to adjust to the limb loss rather than the level of amputation.Objectiveto compare the cardiorespiratory responses to CPET of very-trained cyclists with AK vs. ND.MethodSix elite male cyclists with AK (n = 3) or ND (n = 3) performed a CPET on their own bicycle placed in Cyclus II ergometer (RBM, Leipzig, Germany). Expired gases were collected breath-by-breath and Stroke volume and cardiac output were measured by impedance cardiography (Physioflow, Manatec, France). Outcome measures included VO2max, peak values of heart rate (HRpeak) and stroke volume (SVpeak), powers associated at VO2max (pVO2max), SVpeak (pSVpeak), Anth and respiratory compensation point (RCP). All data are expressed as the mean and standard deviation (±SD). Welch test was performed to compare AK and ND groups. The effect size (ES) was characterized as small (0.2–0.4), medium (0.5–0.8), or large (> 0.8) according to the Cohen's d value.ResultsAs shown in Table 1, no significant differences were observed between AK and ND for VO2max and pVO2max (large ES). The nature of impairment had not significant effect on values of HRpeak and SVpeak. AK resulted in lower Anth values and an early attainment of SVpeak during CPET.ConclusionCyclists with AK reached their peak value of SV at lower power intensity, which could be limited in their capacity to perform compared to ND athletes. Residual muscle strength between amputations, tetraplegic, paraplegic and other spinal cord injury requires detailed biomechanical and physiological investigations in order to measure precisely the impact of disability on cycling performance.