Pacing Strategy, Muscle Fatigue, and Technique in 1500-m Speed-Skating and Cycling Time Trials.
OBJECTIVE
To evaluate pacing behavior and peripheral and central contributions to muscle fatigue in 1500-m speed-skating and cycling time trials when a faster or slower start is instructed.


METHODS
Nine speed skaters and 9 cyclists, all competing at regional or national level, performed two 1500-m time trials in their sport. Athletes were instructed to start faster than usual in 1 trial and slower in the other. Mean velocity was measured per 100 m. Blood lactate concentrations were measured. Maximal voluntary contraction (MVC), voluntary activation (VA), and potentiated twitch (PT) of the quadriceps muscles were measured to estimate central and peripheral contributions to muscle fatigue. In speed skating, knee, hip, and trunk angles were measured to evaluate technique.


RESULTS
Cyclists showed a more explosive start than speed skaters in the fast-start time trial (cyclists performed first 300 m in 24.70 ± 1.73 s, speed skaters in 26.18 ± 0.79 s). Both trials resulted in reduced MVC (12.0% ± 14.5%), VA (2.4% ± 5.0%), and PT (25.4% ± 15.2%). Blood lactate concentrations after the time trial and the decrease in PT were greater in the fast-start than in the slow-start trial. Speed skaters showed higher trunk angles in the fast-start than in the slow-start trial, while knee angles remained similar.


CONCLUSIONS
Despite similar instructions, behavioral adaptations in pacing differed between the 2 sports, resulting in equal central and peripheral contributions to muscle fatigue in both sports. This provides evidence for the importance of neurophysiological aspects in the regulation of pacing. It also stresses the notion that optimal pacing needs to be studied sport specifically, and coaches should be aware of this.
Center of Human Movement Sciences, University Medical Center of the University of Groningen, Groningen, the Netherlands.
Inge K
IK
Stoter
Brian R
BR
MacIntosh
Jared R
JR
Fletcher
Spencer
S
Pootz
Inge
I
Zijdewind
Florentina J
FJ
Hettinga
D056352:Athletes; D054874:Athletic Performance / Q000502:physiology*; D001642:Bicycling / Q000502:physiology*; D006621:Hip Joint; D006801:Humans; D007719:Knee Joint; D019344:Lactic Acid / Q000097:blood; D008297:Male; D009119:Muscle Contraction; D018763:Muscle Fatigue / Q000502:physiology*; D052097:Quadriceps Muscle / Q000502:physiology*; D012861:Skating / Q000502:physiology*; D013997:Time Factors; D060726:Torso; D055815:Young Adult
D019344:Lactic Acid