Why your muscles don't hurt as much the second time you lift weights
The repeated bout effect and heat shock proteins: intramuscular HSP27 and HSP70 expression following two bouts of eccentric exercise in humans.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
When you do a tough workout that hurts your muscles, the next time you do the same workout a month later, your muscles don't hurt as much. But your body doesn't make more of the stress proteins (HSPs) the second time — instead, it starts with less of them already in the muscle.
Surprising Findings
HSP27 and HSP70 increased the same amount after both workouts, even though muscle damage was dramatically lower the second time.
Common belief is that the body ramps up protective proteins to prevent future damage—but here, protection improved without any increase in HSP response.
Practical Takeaways
If you're new to resistance training, know that your first intense workout will be the hardest—your body will adapt quickly, and soreness will drop significantly after just one repeat session.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
When you do a tough workout that hurts your muscles, the next time you do the same workout a month later, your muscles don't hurt as much. But your body doesn't make more of the stress proteins (HSPs) the second time — instead, it starts with less of them already in the muscle.
Surprising Findings
HSP27 and HSP70 increased the same amount after both workouts, even though muscle damage was dramatically lower the second time.
Common belief is that the body ramps up protective proteins to prevent future damage—but here, protection improved without any increase in HSP response.
Practical Takeaways
If you're new to resistance training, know that your first intense workout will be the hardest—your body will adapt quickly, and soreness will drop significantly after just one repeat session.
Publication
Journal
Acta physiologica Scandinavica
Year
2002
Authors
H. S. Thompson, P. Clarkson, S. Scordilis
Related Content
Claims (4)
When you do the same weight workout more than once, your muscles get better at handling it — so next time, you’re less sore and damaged.
If you do a tough workout that stretches your muscles hard (like lowering weights slowly), then wait four weeks and do it again, your muscles won’t hurt as much or get as damaged the second time—they adapt and get tougher.
After you do a tough workout that stretches your muscles (like lowering weights slowly), your body gets better at handling the stress—so the next time, your muscles don’t need to produce as many protective proteins at rest.
Even when your muscles don’t get as sore the second time you do a tough workout, your body still makes the same amount of protective proteins (HSP27 and HSP70) as it did the first time.