The Study
Circadian Rhythm and Physical Fatigue Separately Influence Cognitive and Physical Performance in Amateur Athletes
This study watched 18 athletes do tests in the morning, afternoon, and evening after getting tired from exercise. It found that sometimes they reacted faster or were stronger at certain times, but it didn't prove that the time of day or tiredness caused those changes—maybe they just felt more awake or practiced more that day.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
This study tested athletes at morning, afternoon, and evening to see how being tired and the time of day affect their strength and thinking speed.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 543 / 100
Quality score
Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — athletes are stronger and react faster after exercise in the evening, which could help timing training or competitions.
- 2Knee strength and fatigue resistance were highest at 6 PM (98.7 Nm vs 90.6 Nm in morning).
- 3Reaction time got faster after exercise (p=0.002), but memory didn't change.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Journal of Functional Morphology and Kinesiology
Year
2024
Authors
P. Karanika, Philip Gallardo, Themistoklis Tsatalas, Giannis Giakas, P. Tsaklis
Related Content
Claims (5)
Human physical performance is highest in the late afternoon or early evening, and this peak timing can be changed by regularly training at other times of day.
In amateur athletes, the impact of physical fatigue on visual reaction time does not change depending on the time of day, and circadian rhythm does not modify this effect.
Amateur athletes who experience physical fatigue from isokinetic exercise and a 20-minute treadmill run show faster visual reaction times during morning, afternoon, and evening sessions.
Amateur athletes produce greater maximum force and experience more fatigue in the evening than in the morning during knee extension exercises.
In amateur athletes, visual memory performance does not change due to time of day or short-term physical tiredness.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.