Greater Breast Support Is Associated With Reduced Oxygen Consumption and Greater Running Economy During a Treadmill Running Task

Abstract

IntroductionBreast pain is a major barrier to running for women. While breast support through the use of sports bras reduces breast-related discomfort, the effect of breast support on running performance is less understood. Therefore, the purpose of the current study was to evaluate the effect of greater breast support on oxygen consumption and running economy during a treadmill running task.MethodsFifteen female recreational runners performed a 10-min treadmill running task at their preferred running speed in each of two sports bra conditions: low support and high support. Participants ran on an instrumented treadmill (1,200 Hz, Bertec) while indirect calorimetry was performed using a metabolic measurement system (100 Hz, TrueOne, ParvoMedics). Average VO2 (absolute and relative) from the third to 10th minutes was used to evaluate oxygen consumption. Running economy was calculated as the distance traveled per liter of oxygen consumed. Paired samples t-tests were used to compare mean oxygen consumption and running economy values between breast support conditions. Correlation analysis was performed to evaluate the relationship between breast size and change in running performance.ResultsGreater breast support was associated with reductions in absolute (p < 0.001) and relative oxygen consumption (p < 0.001; LOW: 30.9 ± 7.1 ml/kg/min; HIGH: 28.7 ± 6.7 ml/kg/min). Greater breast support was associated with increases in running economy (p < 0.001; LOW: 88.6 ± 29.1 m/L O2; HIGH: 95.2 ± 31.1 m/L O2). No changes in temporospatial characteristics of running were observed including cadence (p = 0.149), step length (p = 0.300) or ground contact time (p = 0.151). Strong positive linear correlations were observed between the change in running performance metrics and breast size (Oxygen Consumption: p < 0.001, r = 0.770; Relative Oxygen Consumption: p < 0.001, r = 0769; Running Economy: p < 0.001, r = 0.807).ConclusionsGreater breast support was associated with reduced oxygen consumption and increased running economy. These findings demonstrate that greater breast support is not only associated with improved comfort but also improved running performance.

Increasing breast support is associated with altered knee joint stiffness and contributing knee joint biomechanics during treadmill running

“…While Fong and Powell reported changes in running bioenergetics, running biomechanics were not reported (15). Several biomechanical factors were suggested to underlie the observed improvements in running performance including altered transverse plane trunk and pelvis kinematics and increased lower extremity stiffness (15). Evidence has demonstrated that increasing levels of breast support are associated with greater peak trunk and pelvis rotation angles as well as greater trunk and pelvis ranges of motion (9), supporting the assertions by Fong and Powell.…”

“…As previous research (15) has demonstrated that breast size influences the effect of sports bra support on running performance, a repeated measures analysis of covariance (ANCOVA) was used to evaluate the effect of breast support on running cadence, stride length and contact time, as well as knee joint biomechanics while accounting for the influence of breast size on dependent variables. In the presence of a significant main effect of breast support, posthoc dependent samples t-tests were used to compare mean values between breast support conditions.…”

“…To reduce these tissue strains and strain rates in the passive female breast, external breast support in the form of a sports bra is commonly used. Evidence demonstrates that breast support provided through the use of a sports bra reduces breast displacement in all planes; however, increasing breast support not only influences breast kinematics but has also been shown to alter running kinematics and bioenergetics (9,15,16).…”

“…Recent research has demonstrated that greater breast support is associated with improved running performance (15). In a sample of female recreational runners, Fong and Powell (15) demonstrated that high compared to low support sports bras were associated with a ∼7% reduction in oxygen consumption and improved running economy while temporospatial characteristics (cadence, step length and ground contact time) were unchanged during a treadmill running task. Moreover, changes in oxygen consumption and running economy were strongly correlated with breast size (r = 0.77 and r = 0.81, respectively).…”

“…Moreover, changes in oxygen consumption and running economy were strongly correlated with breast size (r = 0.77 and r = 0.81, respectively). While Fong and Powell reported changes in running bioenergetics, running biomechanics were not reported (15). Several biomechanical factors were suggested to underlie the observed improvements in running performance including altered transverse plane trunk and pelvis kinematics and increased lower extremity stiffness (15).…”