Distribution of Power Output during the Cycling Stage of a Triathlon World Cup

BERNARD, T., C. HAUSSWIRTH, Y. LE MEUR, F. BIGNET. S. DOREL and J. BRISSWALTER. Distribution of Power Output during the Cycling Stage of a Triathlon World Cup. Med. Sci. Sports Exerc., Vol. 41, No. 6, pp. 1296-1302, 2009. Purpose: The aim of this study was to evaluate the power output (PO) during the cycle phase of the Beijing World Cup test event of the Olympic triathlon in China 2008. Methods: Ten elite triathletes (5 females, 5 males) performed two laboratory tests: an incremental cycling test during which PC), HR at ventilatory thresholds (V-T1 and V-T2), and maximal aerobic power (MAP) were assessed, and a brief all-out test to determine maximal anaerobic power output (MAnP). During the cycle part of competition, PO and FIR were measured directly with portable device. The amount of time spent below PO at V-T1 (zone 1), between PO at V-T1 and V-T2 (zone 2), between PO at V-T2 and MAP (zone 3) and above MAP (zone 4) wits analyzed. Results: A significant decrease in PO, speed, and HR values was observed during the race. The distribution of time was 51 +/- 9% for zone 1, 17 +/- 6% for zone 2, 15 +/- 3% for zone 3, and 17 +/- 6% was performed at workloads higher than MAP (zone 4). From HR values, the triathletes spent 27 +/- 12% in zone 1, 26 +/- 8% in zone 2, and 48 +/- 14% above V-T2. Conclusions: This study indicates a progressive reduction in speed, PO, and FIR, coupled with an increase in variability during the event. The Olympic distance triathlon requires a higher aerobic and anaerobic involvement than constant-workload cycling exercises classically analyzed in laboratory settings (i.e., time trial) or Ironman triathlons. Furthermore, monitoring direct PO could be more suitable to quantify the intensity of a race with pacing strategies than classic HR measurements.