The effects of constant vs. variable workload cycling on performance and perception

BACKGROUND: Lhe purpose of this study was to determine whether constant load (CL) cycling or variable load (VL) cycling stimulates different physiological and psychological responses. METHODS: Recreationally-trained male cyclists (N.=8, age 32±5 yr, weight 75.7± 10.9 kg, body fat 13.4±5.6%, VO_2peat4.60±0.62 L/min) completed two experimental trials. During the VL trial, participants alternated between 3 minutes at 45% and 3 minutes at 85% of maximal aerobic power during the 63-minute trial. During the CL trial, participants cycled at a constant 65% of maximal aerobic power for 63 minutes. The total amount of work was held constant for the two trials. Immediately following each trial, participants completed a maximal 10-km performance trial. Blood lactate was measured at 6, 30, and 60 minutes of cycling as well as at the beginning and conclusion of the performance trial. RESULTS: Time trial performance was not different between VL (16.97±2.07 min) and CL (16.81±1.47 min, P=0.624). There was no difference in VO₂ (P=0.429), heart rate (P=0.640), blood lactate (P=0.520), rated perceived exertion (RPE) (P=0.216), Feeling Scale (P=0.626), or attentional focus (P=0.315) between VL and CL 10-km performance time trials. However, RPE (P=0.003) and attentional focus (P=0.016) were elevated in VL. CONCLUSIONS: These data indicate that VL and CL cycling have no differential effect on subsequent performance or physiology despite differences in perception during the experimental trials.