SPORTS BRA SUPPORT ALTERS METABOLIC COST AND ECONOMY PROFILES DURING TREADMILL RUNNING

Abstract

1,2Alexis K. Nelson, 2Jay J. Hinton, 2Hailey B. Fong, 2Julie E. Woolfolk, 1,2Douglas W. Powell FACSM1University of Tennessee Health Science Center, 2University of Memphis Sponsor: Douglas W. Powell, FACSM The breast is a passive tissue that has been described as a wobbling mass on a rigid torso. With limited intrinsic support, female athletes are required to provide extrinsic breast support from a sports bra. Little is known about the influence of sports bra support on the bioenergetics of running. Only a single study with a small sample size has investigated sports bra support-related changes in oxygen consumption during a running task. PURPOSE: To quantify the effect of sports bra support on metabolic cost of running and running economy. METHODS: 14 female recreational runners performed a 10-minute treadmill running task at their preferred speed in each of 2 randomized sports bra support conditions: low support (LOW) and high support (HIGH), where the conditions were characterized by the athlete wearing a low or high supports bra, respectively. Indirect calorimetry was recorded for each 10-minute trial using a metabolic measurement system (Parvo Medics, Sandy, UT). Metabolic cost was calculated as the average VO2 measured across the duration of the trial while running economy was calculated as the quotient of the running distance divided by the sum of the VO2 across each 10-minute trial. A paired samples t-test was used to compare mean oxygen consumption and running economy values in the LOW and HIGH conditions. RESULTS: HIGH was associated with lower metabolic cost (L/min, p = 0.004) and improved running economy (m/L O2, p = 0.004) compared to LOW. CONCLUSIONS: Sports bra support alters the metabolic cost and economy of running. Underlying mechanisms may be related to increased pelvic and trunk rotation allowing runners to take longer strides without the burden of high breast accelerations.