Absolutely +1 on the exercise. For me it's road biking. I just hop on farm roads and ride for hours listening to Audible, podcasts, or nothing at all and just enjoy the scenery.
Also - and I can't stress this enough - absolutely use your vacation time. And when you do, utterly disconnect from work. Turn "do not disturb" on your phone and other devices and not only don't answer work emails, don't even look at email, slack, etc.
I agree with the comment about doing whatever it is that will relax you. Sometimes that is just binge watching the latest Netflix show. But, if you work from home, I've found that absolutely nothing beats GOING somewhere for your vacation time. I - and friends who also WFH - find that just being at home on vacation can still be emotionally draining. Even a 4 day weekend away from home doing something completely different can be very recharging.
Even if I've come back to work and had to fix things others "broke" because they had to work around me not being there, I was much happier with that than if I did any work during my time away. And it also pointed out to me where documentation and knowledge was lacking or tools could be improved, etc. ;)