The Study
Circadian rhythm effect on physical tennis performance in trained male players
This study tested the same tennis players in the morning and afternoon to see when they played better. Because they did both tests, we can say the time of day probably made a difference — but only for these 13 guys. It doesn't prove it works the same for everyone.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Tennis players tested in the morning were slower and weaker in key movements than when tested in the afternoon, but their grip strength stayed the same.
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 549 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — these differences are large enough to affect match performance, especially in fast, explosive actions like serving and sprinting.
- 2Serve speed dropped from 175.2 to 168.5 km/h; jump height dropped from 33.7 to 32.2 cm; agility time worsened from 9.91 to 10.14 seconds; sprint time worsened from 1.69 to 1.74 seconds.
- 3Grip strength didn't change.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Journal of Sports Sciences
Year
2017
Authors
Á. López-Samanes, D. Moreno-Pérez, J. Maté-Muñoz, R. Domínguez, J. Pallarés, R. Mora‐Rodriguez, J. Ortega
Related Content
Claims (4)
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.
Highly trained male tennis players perform worse on serve velocity, accuracy, jump height, agility, and sprint speed in the morning compared to the afternoon.
In highly trained male tennis players, handgrip strength measured in the morning is the same as handgrip strength measured in the afternoon.
Highly trained male tennis players perform better in serve velocity, power, speed, and agility when training in the afternoon rather than in the morning.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.