Researchers’ understanding of overtraining syndrome (OTS) is guiding their advice for athlete return to sport in the case of post COVID-19 condition, also known as long-COVID. Those experiencing long-COVID should moderate their activity in the same way as overtrained athletes, with “symptom-titrated physical activity,” the gradual reintroduction of intensity based on close monitoring of an individuals’ symptoms. In the case of both OTS and long-COVID, there is no one-size-fits-all recovery.