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Diurnal physiological and immunological responses to a 10-km run in highly trained athletes in an environmentally controlled condition of 6 °C

Fogarty, M. C.; Davison, R. C.R.; Florida-James, G. D.; Davison, R. C. R.; Fogarty, Mark; Boukelia, Boukhemis; Davison, Richard; Florida-James, Geraint


Boukhemis Boukelia

Dr Mark Fogarty
Lecturer of Sport and Exercise Nutrition and Director of Student Experience

R. C. R. Davison

G. D. Florida-James

R. C. R. Davison


Purpose The Clara cell protein CC16, secreted from Clara cells in the lung, is discussed as a potential biomarker for toxic effects on the airways. An increased concentration of CC16 in serum may be caused by increased permeability of the lungs. To investigate the changes in P-CC16 in response to an intense exercise bout performed at different times of day (9 am and 4 pm) of highly trained individuals. Method Using a crossover randomized design, 8 runners (mean VO2max 71 ml kg−1 min−1, SD 6) performed a 10-km time trial run, at 9 am and 4 pm, in an environmental chamber set at 6 °C. Lung function tests and blood sampling occurred at baseline, immediately post and 1 h post time trial. Result Diurnal differences (P < 0.05) were found for blood neutrophil and lymphocyte counts; with higher values at 4 pm. P-CC16 was higher at the pre- and post-trial time point at 9 am compared to 4 pm. Lung function was not different between or within trials. Conclusion Morning trial in cold condition caused more physiological strain compared to the same trial in the evening. However, this extra stress caused by zeitgebers could be a useful strategy for athletes, coaches, and general population to improve their running performance and protect their health in cold conditions in the long-term plan.

Journal Article Type Article
Publication Date Jan 1, 2017
Journal European journal of applied physiology
Print ISSN 1439-6319
Electronic ISSN 1439-6327
Publisher Springer Verlag
Peer Reviewed Peer Reviewed
Volume 117
Issue 1
Pages 1-6
Keywords Immunological markers, CC16, Diurnal variation
Publisher URL
Additional Information This is a copy of an open access article published in: European journal of applied physiology, 2017, v.117 issue 1.


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