Optimizing Arm Cycling Exercise Prescription: Comparative Analysis with Leg Cycling and Current Guidelines

Introduction Exercise is widely recognized as a strategy for improving physical fitness and achieving caloric deficit. Nevertheless, arm cycling ergometry (AC) has yet to be compared with leg cycling (LC) at gas exchange threshold (GET) intensities to inform exercise duration recommendations based on physical activity and exercise guidelines in males and females. The purpose of this study was to evaluate the time required to expend 100 kcal (T100) in AC and LC performed at moderate (MOD) and heavy (HVY) exercise intensity domains. Methods Healthy male and female adults ( n = 37; body mass index = 25.6 kg·m −2 ) completed randomized and counterbalanced T100 trials combining AC and LC at MOD and HVY. Predictors of T100 (age, sex, fitness level, skeletal muscle mass) were investigated using linear regressions. Additionally, the associated pulmonary, gas exchange, and metabolic responses, along with participants’ ratings of perceived exertion and exercise enjoyment, were assessed. Three-way analyses of variance assessed mode, intensity, and sex effects. Results Main effects showed that T100 was nearly 25% longer in AC compared with LC trials (AC = 19.30 ± 0.54 min, LC = 15.23 ± 0.54 min; P < 0.01; d = 1.18) and 40% longer for MOD (MOD = 20.85 ± 0.49 min, HVY = 14.09 ± 0.49 min; d = 2.08). Female T100 was longer than male T100 during LC ( P < 0.001; d = 1.44) and HVY ( P < 0.001; d = 1.42), with even larger effects during AC ( P < 0.001; d = 2.25) and MOD ( P < 0.001; d = 2.27). Perceived exertion was influenced by intensity, and enjoyment levels were only influenced by sex. Mode-specific oxygen consumption at GET and peak oxygen uptake were notable correlates of T100. Conclusion Mode-specific cardiorespiratory fitness significantly impacts caloric expenditure in healthy adults, and T100 exercise durations can inform exercise prescriptions for AC and LC.