Rapamycin Does Not Compromise Exercise‐Induced Muscular Adaptations in Female Mice

Even when taking rapamycin, female mice still get stronger and fitter from using a weighted exercise wheel — the drug doesn't stop their workout gains.

In female mice that exercised with weighted wheels for 8 weeks, taking the drug rapamycin — even just once a week — made their blood sugar control worse, but doing it less often caused fewer problems.

Female mice on a weekly rapamycin dose ran more and faster than those on a more frequent dose or no drug, but despite running more, they didn’t lose more fat or get healthier metabolically.

In female mice that exercised with weighted wheels for 8 weeks, giving rapamycin three times a week blocked a key muscle signaling pathway, but giving it just once a week let the pathway bounce back a bit between doses — showing that how often you give the drug really changes how it works in muscles.

Even when mice are given a drug that blocks a key muscle growth pathway, running with added weight still makes their leg muscles bigger — showing that exercise can build muscle even when that pathway is turned down.

Taking rapamycin between workouts might help your muscles clean out junk and rebuild stronger as you age — like getting the best of both rest and exercise.