Endurance is built not only in the muscles. The brain, it turns out, actively triggers processes that help the body adapt to exertion and prepare for future workouts.
At the center of the discovery are SF1 neurons in the hypothalamus. When scientists switched them off in mice, their muscles no longer adapted normally to regular training, and their endurance gains stopped. The researchers then conducted the reverse experiment: they artificially activated these neurons for an hour after running. The result was striking — endurance increased more than usual.
After a workout, the brain enters a kind of “learning window.” It not only receives signals from tired muscles but also helps trigger their metabolic remodeling. This suggests that the effects of training are linked not only to the muscles but also to neuroplasticity — the brain’s ability to change in response to experience. However, this mechanism has so far been identified only in mice.
