~ \.c'~ 'c " Physical Fitness and Performance Effect of Warm-Up on Cycle Time Trial Performance

the effect of warm-up on 3-km cycling time trial (TT) perfonnance, and the influence of accelerated V02 kinetics on such effect. Methods: Eight well-trained road cyclists, habituated to 3-km time trials, perfonned randomly ordered 3-km TT after a) no warm-up (NWU), b) easy warm-up (EWU) (15 min comprised of 5-min segments at 70,80, and 90 % of ventilatory threshold (VT) followed by 2 min of rest), or c) hard warm-up (HWU) (15 min comprised of 5-min segments at 70, 80, and 90 % VT. plus 3 min at the respiratory compensation threshold (RCT) followed by 6 min of rest). V02 and power output (SRM), aerobic and anaerobic energy contributions, and V02 kinetics (mean response time to 63 % of the V02 observed at 2 kIn) were detennined throughout each TT. Results: Three-kilometer TT perfonnance was (P < 0.05) improved for both EWU (266.8:t 12.0 s) (-2.8%) and HWU (267.3:t 10.4 s) (-2.6%) versus NWU (274.4:t 12.1 s). The gain in perfonnance was predominantly during the first 1000 m in both EWU (48 % of gain) and HWU (53 % of gain). This reflected a higher power output during the first lOOO m in both EWU (384 W) and HWU warm-up (386 W) versus NWU (344 W) trials. The mean response time was faster in both EWU (45:t 10 s) and HWU (41:t 12 s) versus NWU (52:t 13 s) trials. There were no differences in anaerobic power output during the trials, but aerobic power output during the first 1000 m was larger during both EWU (203 W) and HWU (208 W) versus NWU (163 W) trials. Conclusions: During endurance events ofintennediate duration (4-5 min), perfonnance is enhanced by warm-up irrespective of warm-up intensity. The improved perfonnance is related to an acceleration of V02 kinetics. Key Words: CYCLING, ENERGY SYSTEMS. SPORTS PERFORMANCE, V02 KINETIC