Excess skin and sagging - Implant placement for a lift? (photos)

I am planning a breast lift with implants. I have spent hours researching different types of implants and the placement of them! I am very sporty and would prefer subglandular placement with b-lite implants? I have had some advice that a lift with subglandular placement will result in sagging? I always had perky and full breasts until I gained a lot of weight during pregnancy and then breastfed for three years. The weight loss I believe caused the excess skin and sagging.