Im 24 with CF, im 5'11 i went from 120lbs to a solid 188lb in 3 years, weight lifting 4-5 days a week....make sure your targeting each muscle group once a week...to cut stay away from heavy lifting and concentrate on high reps with a low fat diet but high in calories and protein due to having CF...depending on your stats weight, height, age....myself having CF being naturally very very skinny...iv been able to bulk up and stay cut at the same time, so i dont ever see a need to cut....iam very knowledgeable in weight lifting and gain weight feel free to ask any questions about nutrition, weight lifting or gainng weight