IMO ..
No.. IMO ..
They would adapt worst - considering there endocrine system is already unstable and not adjusted for maturity. There bones have not fused and muscles not fully developed - not to mention they would be skipping out on getting a solid natural base first. They would be more susceptible to the long term side effects and more sensitive to the secondary sexual sides.
Gain keeping is more relative to your post-cycle gear (clomid-hcg-nolva), nutrition and training - no matter what age you are.