Will the lengthening affect my performance at the gym after everything (hopefully) completely recovers? I am a very athletic guy and I am also pretty good at running long distances and sprinting. I hit the gym 4-5 times a week and I love lifting heavy weights (especially squats and deadlifts), will I be able to be that strong after my recovery?
Weight lifting seems to be negligibly affected by leg lengthening, especially if one is only doing 5 or so cm. As for endurance running and sprinting, some have reported difficulty pursuing those activities post leg lengthening, which is most likely to the new biomechanics the body has to adjust to. However, with 5 cm of lengthening, the body shouldn't have a tremendous amount of trouble adjusting to the new biomechanics.
If you are truly concerned with recovery muscular strength and endurance post ll, I would highly advise lengthening with Dr. Guichet. He has a team of FIFA personal trainers that rehabilitate you during the lengthening process. This is why I'm going with him, because I'm an amateur powerlifter and strongman.