Non sleep deep rest is a deep relaxation technique that can be used in place of a nap without getting groggy. It gives you energy and has countless benefits. I do it often and it helps me especially if i got poor sleep. Here is Dr Andrew Huberman’s guide on his website, but he also has 10, 20, and 30 minute guided NSDR audios for free on youtube, which i will put in the comments https://www.hubermanlab.com/nsdr#:~:text=Non%2Dsleep%20deep%20rest%20does,20%2D30%20minutes%20if%20possible.