Exercise helps because it completes the stress cycle[1]. When burnt out it can be hard to find time, so try one of these and see if they help:

* High intensity intervals. Do 2 minutes of light intensity cardio as warm up. Then alternate 20 seconds at top effort with 10 seconds of rest. 10 cycles of this will only take you 5 minutes. You should be out of breath by the end. * Faster version of yoga woodchopper pose[2]. Stand with feet apart and knees slightly bent. Clasp hands and raise above head. Bend knees and bring your hands down while you exhale with a loud "Ha!" Do it slow a few times for warm up, then do it fast and imagine your hands crushing a stressor at the bottom. Yell if it won't disturb the neighbors. * Tense your whole body for 20 seconds, then slowly exhale and release the tension. While tensing, imagine either beating up or successfully running away from something that is stressing you out.

[1] https://www.feministsurvivalproject.com/episodes/episode-02-... [2] https://youtube.com/watch?v=u1HjZ49xAPc