Are Subglandular Implants the best choice for my athletic body shape if I'm seeking a natural look? (photo)

Thank you for the question and picture. Based on your pictures, I think you are starting a great “starting place” and should have a very nice outcome with breast augmentation surgery. Given your body type, I would agree with the use of silicone gel breast implants placed in the sub muscular (dual plane) position.
Generally speaking, the best online advice I can give to ladies who are considering  breast augmentation surgery ( regarding breast implant size/profile selection) is:
1. Concentrate on choosing your plastic surgeon carefully.  Concentrate on appropriate training, certification, and the ability of the plastic surgeon to achieve the results you're looking for. Ask to see lots of examples of his/her work.
2. Have a full discussion and communication regarding your desired goals  with your plastic surgeon. This communication will be critical in determining  breast implant size/type/profile will most likely help achieve your goals. 
In my practice, the use of photographs of “goal” pictures (and breasts that are too big or too small) is very helpful. I have found that the use of words such as  “natural” or “C/D cup”  etc means different things to different people and therefore prove unhelpful.
 Also, as you know, cup size varies depending on him who makes the bra; therefore, discussing desired cup  size may also be inaccurate.
 The use of computer imaging technology may also be very helpful during this communication process.
3.  Once you feel you have communicated your goals clearly,  allow your plastic surgeon to use his/her years of experience/judgment to choose the breast implant size/profile that will best meet your goals.  Again, in my practice, this decision is usually made during surgery.
I hope this (and the attached link) help.

I like subglandular implants more and more, I know under the muscle is all the rage but alot of animation deformities as well as implant displacement is due to a muscle pushing on the implant, a small 230-260 implant under your gland will be great