Complex sentence: Before "The X Factor", he did both ballet and gymnastics, but his career as a gymnast was cut off by a broken wrist, and he struggled with his weight when he was no longer exercising so much.
Split into simpler sentences: Before "The X Factor", he did both ballet and gymnastics. His career as a gymnast was cut off by a broken wrist, and he struggled with his weight when he was no longer exercising so much.