Published in:
01-05-2012 | Original Article
The energetics of ultra-endurance running
Authors:
Stefano Lazzer, Desy Salvadego, Enrico Rejc, Antonio Buglione, Guglielmo Antonutto, Pietro Enrico di Prampero
Published in:
European Journal of Applied Physiology
|
Issue 5/2012
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Abstract
Our objective was to determine the effects of long-lasting endurance events on the energy cost of running (C
r), and the role of maximal oxygen uptake (VO2max), its fractional utilisation (F) and C
r in determining the performance. Ten healthy runners (age range 26–59 years) participated in an ultra-endurance competition consisting of three running laps of 22, 48 and 20 km on three consecutive days in the North–East of Italy. Anthropometric characteristics and VO2max by a graded exercise test on a treadmill were determined 5 days before and 5 days after the competition. In addition, C
r was determined on a treadmill before and after each running lap. Heart rate (HR) was recorded throughout the three laps. Results revealed that mean C
r of the individual laps did not increase significantly with lap number (P = 0.200), thus ruling out any chronic lap effect. Even so, however, at the end of lap 3, C
r was 18.0% (P < 0.001) greater than before lap 1. In addition, a statistically significant acute lap effect on C
r was observed at the end of the second and third laps (by 11.4 and 7.2%, respectively). The main factors determining performance were VO2max, F, as estimated from the average HR, and the average C
r-mean throughout the three laps; the grand average speed over the three laps being described by v
end-mean = F × VO2max × C
r-mean
−1
. We concluded that (1) the substantial increase of C
r-mean during the competition yields to marked worsening of the performance, and (2) the three variables F, VO2max and C
r-mean combined as described above explaining 87% of the total competition time variance.