Dose-response relationship between light exposure and cycling performance

作者：Knaier R; Meister S; Aeschbacher T; Gemperle D; Rossmeissl A; Cajochen C; Schmidt Trucksass A^*

来源：Scandinavian Journal of Medicine & Science in Sports, 2016, 26(7): 794-801.

DOI：10.1111/sms.12535

• Bright light
• physical performance
• circadian rhythm
• chronotype
• time-trial

Light has a stimulating effect on physical performance if scheduled according to the chronotype, but dose-dependent effects on performance have not yet been examined. Three groups of healthy men (25.1 +/- 3.1 years) were exposed to light for different durations in a parallel group design before a 40-min time-trial. In each group, subjects were exposed to either bright light (BL, 4420lx) or moderate light (ML, 230lx) in a randomized order in a crossover design. The durations of light exposure were 120min prior to and during exercise (2HEX; n=16), 60min prior to and during exercise (1HEX; n=10), or only for 60min prior to exercise (1H; n=15). Total work performed during the time-trial in kJ in the 2HEX group was significantly higher in the BL setting (527kJ) than in ML (512kJ) (P=0.002), but not in 1HEX (BL: 485kJ; ML: 498kJ) or 1H (BL: 519kJ; ML: 514kJ) (P=0.770; P=0.485). There was a significant (P=0.006) positive dose-response relationship between the duration of light exposure and the work performed over the three doses of light exposure. A long duration light exposure is an effective tool to increase total work in a medium length time-trial in subjects normalized for their individual chronotype.

• 出版日期2016-7