reason #2, 3 and 4 to eat well and exercise regularly
since #1 is really to feel good and happy,
2, 3 and 4 should be because it makes your immune system stronger! When you’re sick, you REALLY can’t do anything in order to get better. Just remember how miserably boring it gets when you can’t go anywhere, can’t hang out with friends and family, etc. THAT is 3 reasons enough to work out!