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


Medicine & Science in Sports & Exercise: June 2009 - Volume 41 - Issue 6 - pp 1296-1302
doi: 10.1249/MSS.0b013e318195a233
Applied Sciences

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 PO, HR at ventilatory thresholds (VT1 and VT2), 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 HR were measured directly with portable device. The amount of time spent below PO at VT1 (zone 1), between PO at VT1 and VT2 (zone 2), between PO at VT2 and MAP (zone 3) and above MAP (zone 4) was 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 VT2.

Conclusions: This study indicates a progressive reduction in speed, PO, and HR, 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.

1Handibio Laboratory, University of Sud Toulon-Var, La Garde, Cedex, FRANCE; 2Research Mission, Laboratory of Biomechanics and Physiology, French National Institute of Sport and Physical Education (INSEP), Paris, FRANCE; and 3French Federation of Triathlon, Saint-Denis-La-Plaine, FRANCE

Address for correspondence: Thierry Bernard, Ph.D., Handibio, EA 3162, University of Sud Toulon-Var, Bât K, BP 20132, 83957 La Garde Cedex, France; E-mail: thierry.bernard@univ-tln.fr.

Submitted for publication June 2008.

Accepted for publication November 2008.

©2009The American College of Sports Medicine