If a certain part is exhausted every time, let the muscles in that part rest for at least 24-48 hours before training.
However, the rest day doesn't mean that you can spend it on your back. It is recommended to go shopping, jump rope, jog and climb mountains on rest days. Don't think that running will lose muscle. Proper aerobic exercise can protect muscles!
On the rest day, you should supplement protein, because all muscles grow at rest, so you should ensure the nutritional supply at this time!