Effects of pedal frequency on VO2 and work output at lactate threshold (LT), fixed blood lactate concentrations of 2 mM and 4 mM, and max in competitive cyclists

Abstract

To determine the effects of differing pedal frequencies on VO2 and work output values at the lactate threshold (LT), fixed blood lactate concentrations of 2 mM and 4 mM (2 mM, 4 mM), and at max, nine male competitive road racing cyclists (USCF category I or II) completed three VO2 max tests; on a Monark bicycle ergometer, at pedal frequencies of 60, 90, and 120 rpm. Each stage was 3 min in duration, starting at 0 kgm/min with subsequent stages increased by either 180 kgm/min (60 and 120 rpm) or 178 kgm/min (90 rpm). Blood samples were taken during the last 30 s of each stage. VO2 and work output at LT, 2 mM, and 4 mM were determined from individual blood lactate-work rate and VO2-work rate relationships. VO2 max and maximal work output were chosen as the peak values observed during the VO2 max tests. Results indicated that work output at LT, 2 mM, and 4 mM was affected by choice of pedal frequency (1278, 1140, 999 kgm/min at LT; 1533, 1450, 1182 kgm/min at 2 mM; 1780, 1703, 1487 kgm/min at 4 mM; for 60, 90, and 120 rpm, respectively, P less than 0.05). Max work output at 60 and 90 rpm was significantly greater (P less than 0.05) than at 120 rpm (2035, 2053, 1879 kgm/min for 60, 90, and 120 rpm, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)