No, training bras have nothing to do with how your breasts will develop. The purpose of training bras is just so when girls begin to develop, start getting their period, they feel a little more grown up. Some little girls are self-conscious due to them starting to develop and their nipples getting larger so training bras cover that up.
Larger breasts will point south when not wearing a bra due to the weight of them. The only thing you can possibly do to help a little is upper body strength training. It won't do anything to the breasts but it strengthens the muscles under and around the breasts, also helps with posture which could make them a bit more perkier due to the muscles behind/around them.
~Tish
CL for: Oral Sex & All About Sex
It's been a long road getting from there to here. I know the wind’s so cold, I’ve seen the darkest days. But now the winds I feel, are only winds of change. I've been thru the fire and I've been thru the rain,
But I'll be fine. 'Cause I've got faith of the heart. ---Rod Stewart
Sometime in your life you will go on a journey,
It will be the longest journey you have ever taken,
It is the journey to find yourself!
---Katherine Sharp