Zadow, EK and Fell, JW and Kitic, C and Han, J and Wu, SSX, Effects of time of day on pacing in a 4-km time trial in trained cyclists, International Journal of Sports Physiology and Performance, 15, (10) pp. 1455-1459. ISSN 1555-0265 (2020) [Refereed Article]
Context: Time of day has been shown to impact athletic performance, with improved performance observed in the late afternoon-early evening. Diurnal variations in physiological factors may contribute to variations in pacing selection; however, research investigating time-of-day influence on pacing is limited.
Purpose: To investigate the influence of time-of-day on pacing selection in a 4-km cycling time trial (TT).
Methods: Nineteen trained male cyclists (mean [SD] age 39.0 [10.7] y, height 1.8 [0.1] m, body mass 78.0 [9.4] kg, VO2max 62.1 [8.7] mL·kg-1·min-1) completed a 4-km TT on 5 separate occasions at 08:30, 11:30, 14:30, 17:30, and 20:30. All TTs were completed in a randomized order, separated by a minimum of 2 d and maximum of 7 d.
Results: No time-of-day effects were observed in pacing as demonstrated by similar power outputs over 0.5-km intervals (P = .78) or overall mean power output (333.0 [38.9], 339.8 [37.2], 335.5 [31.2], 336.7 [35.2], and 334.9 [35.7] W; P = .45) when TTs were performed at 08:30, 11:30, 14:30, 17:30, and 20:30. Preexercise tympanic temperature demonstrated a time-of-day effect (P < .001), with tympanic temperature higher at 14:30 and 17:30 than at 08:30 and 11:30.
Conclusion: While a biological rhythm was present in tympanic temperature, pacing selection and performance when completing a 4-km cycling TT were not influenced by time of day. The findings suggest that well-trained cyclists can maintain a robust pacing strategy for a 4-km TT regardless of time of the day.
|Item Type:||Refereed Article|
|Keywords:||athletic performance, cycling, diurnal rhythms, energy expenditure, power output|
|Research Division:||Health Sciences|
|Research Group:||Sports science and exercise|
|Research Field:||Exercise physiology|
|Objective Division:||Expanding Knowledge|
|Objective Group:||Expanding knowledge|
|Objective Field:||Expanding knowledge in the health sciences|
|UTAS Author:||Fell, JW (Associate Professor James Fell)|
|UTAS Author:||Kitic, C (Dr Cecilia Kitic)|
|Web of Science® Times Cited:||3|
|Deposited By:||Health Sciences|
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