Whether you're on the bike or running, you're going to want as little breast movement as possible. A proper sports bra offers secure support and maximum comfort – allowing you to exercise without distraction or discomfort. It should also be breathable and, of course, fit you properly! But exactly which is the right model for you depends on a combination of factors. You'll need to consider the intensity of exercise you'll wear it for, the amount of compression or encapsulation you personally prefer, and your own cup size.