I experience nausea when I exercise?

hi my name is (—).I experience nausea when i exercise.Could it be caused by second hand smoke because i spend at least 7 hours a week around smokers.People have said its because i am unfit but have been unfit many times and havent had this problem and it started when i started to hang around smokers

Age: 29
Male
Medications: Non
Yes
General Information: Used to take aripripazole but have been off it for 4 months now