A 1.5hr meeting cooks me. After a showcase, which can go for 2 hours, I'm done for the day.
However what works for me isn't having a rest, or flicking through YT for some quick mental rewards. A good walk, or doing some gardening, mowing the lawns - basically anything physical - helps me regenerate. Especially being outside.
That's been a big benefit of working from home. Yesterday at lunchtime I just went out back with a skillsaw and cut a whole bunch of wood for an hour (not random cutting, I need it for a project haha). Came back in feeling great!