I think I struggle the most in this area.  I don't enjoy a gym setting so I utilize stretching and strengthening at home.

I sometimes don't set time aside and have to remind myself that in choosing some stretching and strengthening, it always benefits my mind and body.

I always feel better, even if it's a few dozen squats, taking the stairs or a daily walk.  I also enjoy stretching every morning for about 10-15 minutes.