Mechanical Power Output and Estimated Metabolic Rates of Nordic Skiers During Olympic Competition

This paper explores whether there may be useful information in estimates of metabolic rates obtained from biomechanical calculations of mechanical power output. Thirteen men were analyzed as they passed a camera on each of three laps on an 11.8° uphill in the 30-km classical technique Olympic Nordic ski event. A 15-segment model was constructed; velocity, stride length, stride rate, mechanical power output, and from this latter measure an estimate of oxygen consumption, were obtained. The average lap velocity was 5.65 m•s −1 (20 km•hr −1 ), the film site velocity was 2.58 m•s −1 , and the correlation between them was 0.75. There were no significant differences from lap to lap in any variable, nor were there dramatic differences between the skiers in the top 14 compared with those finishing in 35th place or slower in stride length or stride rate. However, the faster skiers had estimated VO 2 from 80 to 112 ml•kg −1 • min −1 on most laps while the slower skiers had values from 53 to 77. If a VO 2 estimated from biomechanical data can ultimately be shown to be accurate, a rather useful tool may have been identified for coaches, athletes, and sport scientists that can be used during competition in endurance events.