That particular issue is known as RED-S: https://en.wikipedia.org/wiki/Relative_energy_deficiency_in_sport https://en.wikipedia.org/wiki/Relative_energy_deficie

That particular issue is known as RED-S: https://en.wikipedia.org/wiki/Relative_energy_deficiency_in_sport https://en.wikipedia.org/wiki/Relative_energy_deficiency_in_... But over-training can happen even with sufficient nutrition (even if it is less likely, as nutrition is a major part of post-exercise recovery).