One physical benefit of stretching is

improved posture
raised heart rate
heightened awareness
improved vision and hearing

-improved posture

Explanation:

Stretching is a form of physical activity that leads to improvements in flexibility, circulation and posture. In stretching, muscles are flexed and relaxed in several specific methods; these include

Dynamic stretches, where motion allowing for the expansion of muscles for a limited period, are carried out. This is usually part of a pre-workout, warm-up routine.Static, where a stretch is held in place for up to 30 second-intervals. These positions are typically very comfortable.  This is usually part of a post-workout, cool-down routine.

Keeps you from getting lung cancer from smoking