1. Let up: relax one's efforts
2. Ease off: to free from something that pains, disquiets, or burdens
3. Loosen up: relax one's muscles before taking exercise
4. Calm down: become quiet or calm, especially after a state of agitation
5. Chill out: to relax instead of worrying or feeling anxious
6. Lie down: a short rest in which one lies down on a bed, sofa, etc.
7. Take time out: a period of time when you stop what you usually do and you rest or do something else instead
8. Sit back: to rest in a comfortable position
Doubts on this article