Metabolic consequences of resistive force selection during cycle ergometry exercise

The purpose of this study was to compare power outputs and blood lactate concentrations ([La−]B) following 30 s of maximal cycle ergometry when resistive forces were derived from total-body mass (TBM) or fat-free mass (FFM). Differences (P < 0.05) in peak power output (PPO), pedal velocity (PV) and resistive forces (RF) were observed when the TBM and FFM protocols were compared (953 ± 114 W vs. 1020 ± 134 W; 134 ± 8 rpm vs. 141 ± 7 rpm; 6 ± 1 kg vs. 5 ± 1 kg, respectively). Blood lactate values ([La−]B) increased (P < 0.01) postexercise for both protocols and were significantly greater for TBM (10.6 ± 1.2 mmol.l−1 vs 11.6 ± 1.1 mmol.l−1, P < 0.05). These findings indicate that the FFM resistive force protocol may maximise adenosinotriphosphate-phosphocreatine (ATP-PC) utilisation with smaller contributions from anaerobic glycolysis when compared with TBM. These results may have important implications in the assessment of high intensity exercise performance.