IMO the energy you expend doing exercise is coming from a completely different place than energy for knowledge work. On the contrary, doing exercise clears your mind and engages your body -- the opposite of sitting at a desk. In my experience you will feel your baseline "mental energy" also start to increase.

I think GP isn't talking about energy used to perform an exercise, which (IMO) indeed comes from "a completely different place". I read their comment as talking about energy required to start doing an exercise, day in, day out. This, at least for me, comes from the same place as energy needed to start writing code at work, or to get out of the house and run and errand. Burnout happens when that energy source becomes depleted or unreliable.

Based on my experience (including lack of the ability to stick to any exercise regimen long-term), I second GP's post.

I also agree that doing exercises helps recover that second type of energy. It's a positive feedback loop - but the problem is, you won't be able to start it if you're too depleted on the "starting energy". Like with an ICE car - the engine does recharge your battery, but you won't be able to start it if the battery is already dead.

Speak for yourself or citation needed as they say.

It's also only anecdata for me, but I do have hobbies that qualify as sports but after an exhausting day at work I want nothing less than to also exhaust my body and this has been a theme forever.

Also doing any kind of exercise in the morning is the worst and it doesn't clear my mind, it makes me want to get back to bed and the motivation to start work is at a complete low. Some people may well feel refreshed or good after exercising, for me it's the complete opposite - but I don't claim authority.

Running was how I fought against my burnout and hatred of work. Exercise can be part of a solution to the problem.

This is certainly true - for some people, running is constitutes a significant net positive (in terms of motivation/rewards).

A few arguments, though:

1. to me, it doesn't seem the case of the OP (if it was, they'd be already doing it)

2. I know only few people who consistently run, so my opinion is that the motivation/energy balance is not positive for the vast majority of the people (at least, from the mid-term onwards)

3. regarding the "exercise" concept, it depends on what one means. exercise as functional-training-at-home-or-in-the-park is hard to carry in the mid/long term; it's terribly boring and I believe only highly motivated people can do it. if one talks about organized sport activities, I'm all for it; it's definitely something that I generally suggest, but my observations is that those who are not already doing one in the 30s/40s, don't find sport fun in general and don't stick to (or even start) one.

Have to figure out if it’s ME because if so doing any normal exercise system, even for beginners, will be a disaster.