The Study
Changes in human skeletal muscle contractility and hormone status during 2 weeks of heavy strength training
This study shows that when some young men did a lot of heavy leg exercises every day, their strength went up and their hormone levels changed. It also found that the men who had bigger changes in strength tended to have bigger changes in testosterone. But we can't say the hormone changes caused the strength gains — they just happened at the same time.
Analysis score
Maximum 72 for a cohort study.
Where the score came from
Some young men who lift weights did leg exercises every day for 2 weeks. Scientists checked their strength, hormones, and signs of muscle breakdown before, during, and after.
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 539 / 100
Quality score
Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.
Key takeaways
Summary
Based on the study abstract and findings.
- 1The strength gain shows muscles adapt quickly.
- 2Hormone drops suggest intense training causes temporary stress, but levels recover fast.
- 3Increased muscle breakdown is expected with heavy training.
- 4Strength went up by 6%.
- 5Testosterone and growth hormone dropped by about 11-12% during training but bounced back 4 days later.
- 6A key muscle breakdown marker in urine went up by 21%.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
European Journal of Applied Physiology
Year
2001
Authors
T. Raastad, T. Glomsheller, T. Bjøro, J. Hallén
Related Content
Claims (4)
If young guys who lift weights do intense training every day for two weeks, their morning hormone levels might dip for a bit—but they bounce back within four days after stopping, so it’s just a short-term blip, not a long-term problem.
When young guys who lift weights do super intense training every day for two weeks, their bodies show signs of breaking down more muscle, based on a specific waste product in their pee.
If young guys who already lift weights do intense leg workouts every day for two weeks, they get about 6% stronger in their leg press, showing their muscles and nerves adapt quickly.
When young guys who lift weights regularly do intense leg workouts for two weeks, those who gain more strength also tend to have bigger increases in their morning testosterone levels.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.