Cortisol, Testosterone & the T/C Ratio

Definition of Cortisol, Testosterone & the T/C Ratio

Cortisol and testosterone are key endocrine markers reflecting the body's catabolic and anabolic states. Cortisol rises during physical and psychological stress, promoting tissue breakdown and energy mobilization. Testosterone supports muscle repair, strength, and anabolic recovery. Their ratio (T/C) is widely used to assess training stress, recovery status, and potential overreaching in athletes.

Performance Relevance

The T/C ratio provides insight into whether an athlete is in a catabolic (high cortisol, low testosterone) or anabolic (low cortisol, high testosterone) state. A suppressed T/C ratio indicates high training stress, insufficient recovery, or risk of overreaching. A rising T/C ratio during recovery reflects restored anabolic capacity, improved tissue repair, and readiness for high‑intensity training or competition.

Core Principle

Exercise acutely elevates cortisol and suppresses testosterone, while recovery reverses this pattern—making the T/C ratio a reliable marker of training load and recovery status.

Key Evidence

Component 1: Acute Hormonal Response to Competition

P. Passelergue & G. Lac

1999

Hormonal Responses to Competitive Stress

In wrestling athletes (n=15), cortisol increased 1.5–2.5× above baseline during competition while testosterone decreased, producing a strongly catabolic hormonal profile. Demonstrates the classic stress‑response pattern.

Component 2: Recovery-Induced T/C Ratio Rebound

M. Elloumi et al.

2003

Endocrine Markers of Recovery

Showed cortisol normalizes within 4–24 hours post‑competition while testosterone rebounds above baseline, producing a high T/C ratio lasting 3–5 days. Confirms the anabolic shift during recovery.

Component 3: Multi-Sport Evidence Base

G. Lac & P. Berthon

2000

Hormonal Responses Across Sports

Observed the same cortisol rise and testosterone suppression in relay running and rugby athletes. Reinforces the consistency of the hormonal pattern across sport types and intensities.

Component 4: Modern Validation in Team Sports

D. Curzi et al.

2024

Hormonal Monitoring in Professional Football

In professional football players (n=24), cortisol and testosterone responses varied by workload and training status, confirming individual variability but supporting T/C ratio as a meaningful recovery marker.

Component 5: Systematic Review of Salivary Markers

R. Neves et al.

2023

Salivary Hormones in Athlete Monitoring

Systematic review of 14 studies identified cortisol and testosterone as the most frequently used salivary biomarkers for monitoring training stress and recovery. Supports their practical utility in applied sport settings.

Conclusion

Across decades of research and multiple sports, the pattern is consistent: exercise elevates cortisol and suppresses testosterone, while recovery reverses these effects, producing a higher T/C ratio. This makes the T/C ratio one of the most reliable endocrine indicators of training load, recovery quality, and potential overreaching. Although individual responses vary based on fitness level and workload, the overall evidence strongly supports using cortisol, testosterone, and their ratio as practical tools for athlete monitoring.

Citation

• P. Passelergue & G. Lac, 1999
• M. Elloumi et al., 2003
• G. Lac & P. Berthon, 2000
• D. Curzi et al., 2024
• R. Neves et al., 2023
• B. Popovic et al., 2019