Is Moderate Intensity Cycling Sufficient To Induce Cardiorespiratory And Biomechanical Modifications Of Subsequent Running?
Résumé
This study sought to determine whether prior moderate intensity cycling is sufficient to influence the cardiorespiratory and biomechanical responses during subsequent running. Cardiorespiratory and biomechanical variables measured after moderate intensity cycling were compared with control running at the same intensity. Eight highly trained, competitive triathletes completed two separate exercise tests; 1) a 10-min control run (no prior cycling) and, 2) a 30-min transition run (preceded by 20-min of variable cadence cycling; i.e., run versus cycle- run). Respiratory, breathing frequency (fb), heart rate (HR), cost of running (Cr), rate constant, stride length and stride frequency variables were recorded, normalised and quantified at the mean response time (MRT), 3rd min, 10th min (steady-state) and overall for the control (CR) and transition (TR) runs. Cr increased (p<0.05) at all respective times during the TR. V[Combining Dot Above]E/V[Combining Dot Above]CO2 and RER were significantly (p<0.01) elevated at the MRT and 10th min of the TR. Furthermore, overall mean increases were recorded for Cr, V[Combining Dot Above]E, V[Combining Dot Above]E/V[Combining Dot Above]CO2, RER, fb (p<0.01) and HR (p<0.05) during the TR. Rate constant values for oxygen uptake were significantly different between CR and TR (0.48 +/- 0.04 vs. 0.89 +/- 0.15; p < 0.01). Stride length decreased across all recorded points during the TR (p<0.05) and stride frequency increased at the MRT and 3 min (p<0.01). The findings suggest that at moderate intensity, prior cycling influences the cardiorespiratory response during subsequent running. Furthermore, prior cycling appears to have a sustained effect on the Cr during subsequent running.