Insomnia is pretty high on the list of pandemic lockdown issues at the moment, not to mention burnout symptoms.

Some people I know can sleep sitting on a plane, and others can scarcely sleep at night, horizontal, in a quiet room, on a soft bed.

A hard workout, waking up early and avoiding caffeine help me a lot with insomnia.

A "hard" workout. A hard workout can send cortisol through the roof and there will be little sleep.

The half-life of cortisol is very short (comparable to that of cocaine):

"The plasma clearance of cortisol is rapid, with a half-life of 66 min at normal hormone levels. With large steroid loads, however, the half-life increases to 120 min."

If you work out in the morning or afternoon, avoid working ~3-4 hours before bed, you should be able to sleep just fine.

Depends on the timing of the workout, but speaking from personal experience an all day hike is perfect for generating a deep, restful night's sleep.