Influence of All-Out and Fast Start on 5-min Cycling Time Trial Performance

AISBETT, B., P. LEROSSIGNOL, G. K. MCCONELL, C. R. ABBISS, and R. SNOW. Influence of All-Out and Fast Start on 5-min Cycling Time Trial Performance. Med. Sci. Sports Exerc., Vol. 41, No. 10, pp. 1965-1971, 2009. Purpose: To examine the influence of two different fast-start pacing strategies on performance and oxygen consumption ((V) over dot O-2) during cycle ergometer time trials lasting similar to 5 min. Methods: Eight trained male cyclists performed four cycle ergometer time trials whereby file total work completed (113 +/- 11.5 kJ; mean +/- SD) was identical to the better of two 5-min self-paced familiarization trials, During the performance trials, initial power output was manipulated to induce either an all-out or a fast start. Power output during the first 60 s of the fast-start trial was maintained at 471.0 +/- 48.0 W, whereas the all-out start approximated a maximal starting effort for the first 15 s (mean power: 753.6 +/- 76.5 W) followed by 45 s at a constant power output (376.8 +/- 38.5 W). Irrespective of starting strategy, power output was controlled so that participants would complete the first quarter of the trial (28.3 +/- 2.9 kJ) in 60 s. Participants performed two trials using each condition, with their fastest time trial compared, Results: Performance time was significantly faster when cyclists adopted file all-out start (4 min 48 s +/- 8 s) compared with the fast start (4 min 51 s +/- 8 s; P < 0.05). The first-quarter (V) over dot O-2 during the all-out Start trial (3.4 +/- 0.4 L.min(-1)) was significantly higher than during the fast-start trial (3.1 +/- 0.4 L.min(-1); P < 0.05). After removal of an outlier, the percentage increase in first-quarter (V) over dot O-2 was significantly Correlated (r = -0.86, P < 0.05) with the relative difference in finishing time. Conclusions: An all-out start produces superior middle distance cycling performance when compared with a fast start. The improvement in performance may be due to a faster (V) over dot O-2, response rather than time saved due to a rapid acceleration.