The Claim

In competitive male athletes, 24-hour sleep deprivation does not significantly alter salivary testosterone or cortisol concentrations during aerobic exercise, while caffeine supplementation at 6 mg/kg modestly reduces the expected rise in cortisol and attenuates the post-exercise decline in testosterone.

Source: Acute Effects of 24-h Sleep Deprivation on Salivary Cortisol and Testosterone Concentrations and Testosterone to Cortisol Ratio Following Supplementation with Caffeine or Placebo

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
48score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

How it works
1 study reviewed
In plain English

In competitive male athletes, staying awake for 24 hours does not change salivary testosterone or cortisol levels during aerobic exercise. Taking 6 mg of caffeine per kilogram of body weight reduces the increase in cortisol and lessens the drop in testosterone after exercise.

See the scientific wording

In competitive male athletes, 24-hour sleep deprivation does not significantly alter salivary testosterone or cortisol concentrations during aerobic exercise, but caffeine supplementation (6 mg/kg) may modestly blunt the expected rise in cortisol and attenuate the post-exercise decline in testosterone, suggesting a potential protective effect on hormonal stress response.

Why this might work

Caffeine blocks signals that tell the brain to release stress hormones, which keeps cortisol from rising too much during exercise after sleep loss. At the same time, caffeine increases adrenaline, which tells the testes to keep making testosterone even when the body is tired and stressed.

Supported mechanismbased on 1 study

What the research says

1 study

  1. Study: Acute Effects of 24-h Sleep Deprivation on Salivary Cortisol and Testosterone Concentrations and Testosterone to Cortisol Ratio Following Supplementation with Caffeine or Placebo

    After going 24 hours without sleep, male athletes didn’t show big changes in their stress or muscle hormones during exercise — but when they took caffeine, their stress hormone didn’t spike as much and their muscle hormone didn’t drop as much, which might help them feel less stressed and recover better.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

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