If I have a breast implant under the muscle, would I have to give up swim training or just reduce my hours in the pool?

You should not have to limit your physical activity because of implants, so consider options for placement that are appropriate to your lifestyle. This could be either having the implants in front of the muscle (subfascial is my preference for that) or using the split muscle method instead of dual plane. Split muscle preserves the muscle attachments, dual plane cuts the muscle and has a high probability of animation deformity and implant displacement.

It is not just the exercise of swimming itself that may not be recommended right after a breast augmentation surgery, it is also not recommended for patients to soak in bodies of water such as pools or sea until their incision lines are healed and do not carry the risk of becoming infected. It will be best to discuss these details with your surgeon.

Thank you for your question.  I prefer having an implant placed under the muscle, even in my athletic patients.  I find the uphold much better, look better and feel better. Once completely healed you should be able to return to all normal activities.  I typically tell my patients no working out or heavy lifting for 4 weeks and then when you re start just start a little on the slower side.  I would suggest seeing a Board Certified Plastic Surgeon in person to evaluate you and discuss your options. Best of luck to you.