Effects of caffeine ingestion on psychomotor state and oxidative stress markers after an 8-km run competition in sleep-deprived recreational runners

ABSTRACT

The current study aimed to investigate the effects of caffeine intake on psychomotor state and oxidative stress markers after an endurance race following 26 hours of sleep deprivation. Ten recreational runners performed four test sessions in a randomized order at 09:00 h after placebo or 5 mg/kg of caffeine ingestion during a reference night (RN) (bedtime: from 22:30 h to 07:00 h) or a night of total sleep deprivation (TSD). At each session, they performed an 8-km running competition around a 400 m outdoor athletic track. Before and after the race, blood samples were taken and psychomotor tests were performed. Concentrations of oxidative stress markers (e.g. glutathione peroxidase (GPX) and superoxide dismutase (SOD)) were quantified and ratings of psychomotor state (e.g. feelings of good-being (FG), stress (FS), and fatigue (FF)) were measured. In comparison with RN, FF increased while GPX, SOD, and FG decreased after the TSD condition. As compared to placebo, caffeine ingestion decreased FS by 12.5% following RN, reduced FF by 16.7%, raised FG by 25%, and did not affect levels of oxidative stress markers following TSD. Therefore, caffeine is an effective strategy to mitigate psychomotor adverse effects induced by TSD without being pro-oxidant during endurance running competition.

KEYWORDS:

• Caffeine
• endurance exercise
• sleep deprivation
• psychomotor state
• oxidative stress

Acknowledgments

The authors wish to express their sincere gratitude to all the participants for their maximal effort and cooperation.

Disclosure of potential conflicts of interest

No potential conflict of interest was reported by the author(s).

Ethical approval

All procedures performed in studies involving human participants were in accordance with the ethical standards of the Faculty of medicine’s research committee, University of Sfax, Tunisia and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

Informed consent

Informed consent was obtained from all individual participants included in the study.

Additional information

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.