Effects of starting strategy on 5-min cycling time-trial performance

The importance of pacing for middle-distance performance is well recognized, yet previous research has produced equivocal results. Twenty-six trained male cyclists (<i> V O</i>_2peak 62.8<u>+</u>5.9 ml ·kg^-1 · min^-1· maximal aerobic power output 340<u>+</u>43 W; mean<u>+</u><i>s</i>) performed three cycling time-trials where the total external work (102.7<u>+</u>13.7 kJ) for each trial was identical to the best of two 5-min habituation trials. Markers of aerobic and anaerobic metabolism were assessed in 12 participants. Power output during the first quarter of the time-trials was fixed to control external mechanical work done (25.7<u>+</u>3.4 kJ) and induce fast-, even-, and slow-starting strategies (60, 75, and 90 s, respectively). Finishing times for the fast-start time-trial (4:53<u>+</u>0:11 min:s) were shorter than for the even-start (5:04<u>+</u>0:11 min:s; 95% CI=5 to 18 s, effect size=0.65, <i>P </i>50.001) and slow-start time-trial (5:09<u>+</u>0:11 min:s; 95% CI=7 to 24 s, effect size=1.00, <i>P </i>50.001). Mean <i>VO</i>_<i>2</i> during the fast-start trials (4.31<u>+</u>0.51 litres · min^-1) was 0.18<u>+</u>0.19 litres · min^-1 (95% CI=0.07 to 0.30 litres · min^-1, effect size=0.94, <i>P</i> =0.003) higher than the even- and 0.18<u>+</u>0.20 litres · min^-1 (95% CI=0.5 to 0.30 litres · min^-1, effect size=0.86, <i>P</i> =0.007) higher than the slow-start time-trial. Oxygen deficit was greatest during the first quarter of the fast-start trial but was lower than the even- and slow-start trials during the second quarter of the trial. Blood lactate and pH were similar between the three trials. In conclusion, performance during a 5-min cycling time-trial was improved with the adoption of a fast- rather than an even- or slow-starting strategy.<br />