NO EFFECT OF CYCLING EXPERIENCE ON LEG CYCLE ERGOMETER EFFICIENCY

Estimates of muscular efficiency in competitive and recreational cycli sts at similar work intensities and cycling frequencies were examined. Twelve healthy college-age male nonsmoker volunteers were grouped as either competitive (CC; N = 6) or recreational (RC; N = 8) cyclists ba sed upon previous cycling experience. Subjects were studied at pedalin g frequencies of 50 and 80 rpm during bouts of graded and submaximal e ndurance (75% VO2peak) exercise. Between rest and 250 W, we observed n o intergroup differences in VO2 (energy input) at either 50 or 80 rpm. Estimates of whole body (gross) muscular efficiency ranged from 15% t o 24% in competitive and 13% to 22% in recreational cyclists at 50 rpm but were not different. Delta (Delta) efficiencies ranged from 20% to 34% in competitive and from 21% to 28% in recreational cyclists. Delt a efficiency decreased from 27% to 21% in competitive cyclists, from 2 5% to 21% in recreational cyclists as a function of pedaling frequency , and was not different between groups. Competitive cyclists rode long er at both 50 rpm (27 +/- 5 min vs 14 +/- 2 min; P < 0.05) and 80 rpm (35 +/- 4 min vs 20 +/- 4 min; P < 0.05). At 50 rpm (3.08 +/- 0.02 l . min(-1) vs 2.78 +/- 0.05 l . min(-1): P < 0.01) and 50 rpm (3.14 +/- 0.01 l . min(-1) vs 2.7 +/- 0.04 l . min(-1): P < 0.001), the mean VO2 was also greater in competitive cyclists. Although both groups showed superior endurance at 80 compared with 50 rpm and total work was appr oximately double competitive cyclists at each pedaling frequency, we o bserved no differences in whole body muscular efficiency during sustai ned exercise at 75% VO2peak. Our results suggested that previous cycli ng experience was of minor importance when comparing cycle ergometer e fficiency between these two groups. The increased endurance at higher pedaling frequencies during submaximal exercise is not explained by al tered muscular efficiency.