When someone tries to lure me to any kind of physical activity

How about no

"Am I supposed to do something or.."

Hahahahahaha... no! - This is so accurate!

LOKK I'M SHORT AND SLIM AND I DON'T LIKE SPORTS AT ALL i make up excuses or do somthing else

Too much effort to turn my head anymore...

When I was in high school I pretended to have asthma and said that I couldn't run just so I wouldn't have to so any physical activity.