Circadian rhythms during cycling exercise and finger-tapping task.
The aim of this study was to follow the circadian fluctuation of the spontaneous pedal rate and the motor spontaneous tempo (MST) in a sample of highly trained cyclists. Ten subjects performed five test sessions at various times of day. During each test session, subjects were required to perform (i) a finger-tapping task, in order to set the MST and (ii) a submaximal exercise on a cycle ergometer for 15 min at 50% of their Wmax. For this exercise, pedal rate was freely chosen. Spontaneous pedal rate and heart rate (HR) were measured continuously. The results demonstrated a circadian variation for mean oral temperature, HR, and MST. Under submaximal exercise conditions, HR showed no significant time-of-day influence although spontaneous pedal rate changed significantly throughout the day. Circadian rhythm of oral temperature and pedal rate were strongly correlated. Moreover, a significant positive correlation was found between MST and pedal rate. Both parameters may be controlled by a common brain oscillator. MST, rest HR, and pedal rate changes follow the rhythm of internal temperature, which is considered to be the major marker in chronobiology, therefore, if there is a relation between MST and pedal rate, we cannot rule out partial dependence of both parameters on body temperature.
Moussay
S
S
Centre de Recherches en Activités Physiques et Sportives (CRAPS UPRES EA 2131), UFR Sciences et Techniques des Activités Physiques et Sportives, Université de Caen Basse Normandie, Caen, France.
Dosseville
F
F
Gauthier
A
A
Larue
J
J
Sesboüe
B
B
Davenne
D
D
D000328:Adult; D001683:Biological Clocks / Q000502:physiology; D001831:Body Temperature; D002940:Circadian Rhythm / Q000502:physiology*; D003627:Data Interpretation, Statistical; D005080:Exercise Test; D005385:Fingers / Q000502:physiology*; D006339:Heart Rate; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D013997:Time Factors