The Claim
Nine weeks of high-load or low-load resistance training in recreationally trained males does not significantly alter basal or acute post-exercise salivary testosterone or cortisol levels.
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.
In recreationally trained men, nine weeks of either heavy or light weight training does not change resting or exercise-induced levels of testosterone or cortisol in saliva.
See the scientific wording
Neither high-load nor low-load resistance training significantly alters basal or acute post-exercise salivary testosterone or cortisol levels in recreationally trained males over nine weeks, suggesting systemic hormonal changes are not a primary driver of hypertrophy or strength adaptations in this population.
When muscles are stretched and contracted under load, physical forces and built-up metabolic byproducts activate internal signals that tell muscle cells to grow and become stronger. These local signals work independently of hormones in the blood, so even if testosterone or cortisol levels stay the same, muscles still grow and get stronger. Training to failure increases how well muscle cells bind testosterone, which may temporarily lower its levels in saliva without reducing its effect on muscle growth.
What the research says
1 studyIn men who lift weights for nine weeks, whether they use heavy or light weights, their stress and testosterone hormones in saliva don’t change much — so those hormones aren’t what’s mainly making them stronger or bigger.
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.