Systematic tightening & release of individual muscle groups throughout the body. Take your attention to a specific muscle group or body part. Then tense all the muscles in that body part tight and hold it for a 3 seconds and release completely. Repeat 1-3× and move to the next body part or muscle group. Used to release tension and promote blood flow. Good pre-massage prep for those who have trouble letting go of mental/muscle tension. Helps prepare body for yoga nidra.