Objective: 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.
Participants: 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.
Methods: 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).
Main Outcome Measurements: 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: 29.7 ÃÂ± 14 cm.s -1;downward: 31.1 ÃÂ± 17 cm.s-1) compared to treadmill running (upward: 81.4 ÃÂ± 21.7 cm.s-1; downward: 100.0 ÃÂ± 25 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.
Key Words: biomechanics, breast discomfort, breast motion, deep water running