When the article talks about "mental exhaustion", it is talking about short-term mental fatigue from the likes of working too long on a mental task. It is not talking about chronic fatigue or burnout due to chronic stress, or ME/CFS, for which exercise may cause worsening of symptoms. In that case stress reduction is likely the better solution, and exercise managed so you are not doing too little or too much. Making…
Burnout, however, does tend to respond positively to exercise over time. Burnout and ME/CFS are very different conditions.
> Making this comment because I suffered (and recovered from) ME/CFS myself.
How were you able to recover from ME/CFS? It seems spontaneous recovery does happen to some, though for others it is a chronic condition that will likely require some future medical advances to overcome.