Brown et al. 2014, Breast pain in female marathon runners

Survey of 1,285 female London Marathon runners. About a third reported exercise-induced breast pain, rising sharply with cup size (over half of those in F-cup or larger), and 17% of those affected said it changed their exercise behaviour. Despite most always wearing a sports bra, many still had pain, pointing to fit and support shortfalls rather than absence of a bra. Moderate (large self-report survey).