Good association between sprint power and aerobic peak power during asynchronuous arm-crank exercise in people with spinal cord injury.

Abstract

To (1) investigate the association between sprint power and aerobic power output (POpeak_GXT) during a graded peak exercise test (GXT); and (2) validate the prediction models of POpeak_GXT based on sprint power and personal and lesion characteristics. Wheelchair users with tetraplegia (<i>N</i> = 35) and paraplegia (<i>N</i> = 58) performed a 30 s-Wingate test and GXT on an asynchronous arm-crank ergometer. Data were split into samples to develop and validate the model. Sprint power (POmean_Wingate and POpeak_Wingate, respectively) and POpeak_GXT were determined. Regression analyses were performed to develop POpeak_GXT prediction models. Candidate independent variables included POmean_Wingate or POpeak_Wingate, age (years), sex, body mass (kg) or BMI (kg/m²), time since injury (TSI, years) and lesion level (tetraplegia/paraplegia). The best model was validated by comparing the predicted POpeak_GXT with measured POpeak_GXT. The best model (<i>R</i>² = 0.76) to predict POpeak_GXT included POmean_Wingate, BMI and all other independent variables. No significant difference was found between measured (68 ± 35 W) and predicted POpeak_GXT (68 ± 30 W, <i>p</i> = 0.97). The ICC was excellent (0.89 with 95% confidence intervals: 0.75-0.95). The 95% limits of agreement for the Bland-Altman plots were wide (-30 to 31 W). Strong associations were found between POmean_Wingate and POpeak_GXT. Although relative agreement was excellent, absolute agreement was low. Implications for rehabilitation There is a strong relationship between peak aerobic power output and sprint power output, both tested on an arm-crank ergometer, in people with spinal cord injury. A prediction model for peak aerobic power output, based on sprint power output and personal and lesion characteristics, showed a high explained variance. The predictive model can give a guideline for choosing the right graded exercise test protocol but should be used with caution.