The Claim
In highly trained male tennis players, morning testing at 9:00 h significantly reduces serve velocity, serve accuracy, countermovement jump height, agility T-test performance, and 10-meter sprint time compared to afternoon testing at 16:30 h, with effect sizes ranging from 0.67 to 1.46.
What the research says
Supports is higher
Support is ahead, but a single strong opposing study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
Highly trained male tennis players perform worse on serve velocity, accuracy, jump height, agility, and sprint speed in the morning compared to the afternoon.
See the scientific wording
In highly trained male tennis players, morning testing (9:00 h) significantly reduces serve velocity and accuracy, countermovement jump height, agility T-test performance, and 10-meter sprint time compared to afternoon testing (16:30 h), with effect sizes ranging from 0.67 to 1.46, indicating that circadian rhythm influences neuromuscular performance in these athletes during sport-specific tasks.
The body's internal clock raises core temperature during the afternoon, making muscles warmer and more elastic, which lets them generate more force and respond faster to brain signals, improving speed and power in movements like serving and sprinting.
What the research says
1 studyStudy: Circadian rhythm effect on physical tennis performance in trained male players
For top tennis players, their bodies just don’t perform as well in the morning as they do in the afternoon—serving slower, jumping lower, and moving less quickly—because their natural body rhythms make them more alert and powerful later in the day.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.