Does deep water running reduce exercise-induced breast discomfort?

Aim: To establish whether exercise-induced vertical breast displacement and discomfort in women with large breasts were reduced during deep water running compared to treadmill running. Methods: Sixteen women (mean age  = 32 years, range 19–43 years; mean mass  = 74.1 kg, range 61–114 kg; mean height  = 1.7 m, range 1.61–1.74 m), who were professionally sized to wear a C+ bra cup, were recruited as representative of women with large breasts. After extensive familiarisation, vertical breast motion of the participants was quantified as they ran at a self-selected stride rate on a treadmill and in 2.4 m deep water. Immediately after running, the subjects rated their breast discomfort and breast pain (visual analogue scale) and their perceived exertion (Borg scale). Breast discomfort, breast pain, perceived exertion, vertical breast displacement and vertical breast velocity were compared between the two experimental conditions. Results: Exercise-induced breast discomfort was significantly less and perceived exertion was significantly greater during deep water running relative to treadmill running. Although there was no significant between-condition difference in vertical breast displacement, mean peak vertical breast velocity was significantly (p<0.05) less during deep water (upward mean (SD): 29.7 (14.0) cm.s−1; downward: 31.1 (17.0) cm.s−1) compared to treadmill running (upward mean (SD): 81.4 (21.7) cm.s−1; downward: 100.0 (25.0) cm.s−1). Conclusion: Deep water running was perceived as a more strenuous but comfortable exercise mode for women with large breasts. Increased comfort was attributed to reduced vertical breast velocity rather than reduced vertical breast displacement.