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

Abstract

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.

Keywords

Immunological markersCC16Diurnal variation

Abbreviations

CC16

Clara cell 16

ELISA

Enzyme-linked immunosorbent assay

FEF

Forced expiratory flow

FEF25–75

Forced expiratory flow 25–75%

FEV1

Forced expiratory volume in 1 s

FEV1R

Forced expiratory volume in 1 s ratio

FVC

Forced vital capacity

HCT

Haematocrit

HGB

Haemaglobin

RBC

Red blood cell

PLT

Platelet

WBC

White blood cells


Autor / Fonte:Boukhemis Boukelia, M C Fogarty, R C R Davison, G D Florida-James European Journal of Applied Physiology 2016 November 9
Link: http://link.springer.com/content/pdf/10.1007%2Fs00421-016-3489-5.pdf