Both are going to impact your athleticism and there's absolutely no guarantee unless you're very young that you will ever recover the same level of athleticism and frankly it's unlikely.
For most people this may not be super easy to perceive because most people aren't at their peak athleticism to begin with so if you have the surgery and train hard you may surpass even your previous level of athleticism before surgery but that's only because they weren't at their peak to begin with. If you are an athlete and you are closer to peak performance than the average person, be prepared to lose athleticism permanently. Lengthening, even at slow rates will induce some amount of muscle fibrosis and you will not be able to reverse that. There are some studies that show higher HGH/IGF-1 levels during lengthening can reduce this (i.e. young patients or via supplementation) but ultimately staying super athletic can't be your top priority with limb lengthening surgery. Don't get me wrong, you should aim to do everything you can to lose as little athleticism as possible, and be optimistic you will recover most of it, but it can't be your number one concern or you are setting yourself up for regret.
https://onlinelibrary.wiley.com/doi/pdf/10.1016/S0736-0266(01)00002-X
(this is a good read if you are interested)
Athletically, I think the biomechanics of proportions for the sport/activity you are interested in will play a role. Longer tibia are more efficient for running for example. In terms of recovery Tibia is a bit more delicate and can handle a lot less lengthening, a lot slower and there are more complications overall as you lengthen more.
Author
Topic: Tibia vs Femur Lengthening impact on athleticism (Read 836 times)