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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.

ObjectiveThe female breast is a passive tissue with little intrinsic support. Therefore, women rely on external breast support (sports bras) to control breast motion during athletic tasks. Research has demonstrated that lower levels of breast support are associated with altered trunk and pelvis movement patterns during running, a common athletic task. However, no previous study has identified the effect of sports bra support on movement patterns during other athletic tasks including landing. Therefore, the purpose of this study was to examine the effects of breast support on trunk and knee joint biomechanics in female collegiate athletes during a double-leg landing task.MethodsFourteen female collegiate athletes completed five double-leg landing trials in each of three different sports bra conditions: no support, low support, and high support. A 10-camera motion capture system (250 Hz, Qualisys, Goteburg, Sweden) and two force platforms (1,250 Hz, AMTI, Watertown, MA, USA) were used to collect three-dimensional kinematics and ground reaction forces simultaneously. Visual 3D was used to calculate trunk segment and knee joint angles and moments. Custom software (MATLAB 2021a) was used to determine discrete values of dependent variables including vertical breast displacement, knee joint and trunk segment angles at initial contact and 100 ms post-initial contact, and peak knee joint moments. A repeated measures analysis of covariance with post-hoc paired samples t-tests were used to evaluate the effect of breast support on landing biomechanics.ResultsIncreasing levels of breast support were associated with reductions in peak knee flexion (Right: p = 0.008; Left: p = 0.029) and peak knee valgus angles (Right: p = 0.011; Left: p = 0.003) as well as reductions in peak knee valgus moments (Right: p = 0.033; Left: p = 0.013). There were no changes in peak knee extension moments (Right: p = 0.216; Left: p = 0.261). Increasing levels of breast support were associated with greater trunk flexion angles at initial contact (p = 0.024) and greater peak trunk flexion angles (p = 0.002).ConclusionsLower levels of breast support are associated with knee joint and trunk biomechanical profiles suggested to increase ACL injury risk.

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The bone-specific physical activity questionnaire (BPAQ) algorithms were developed from ground reaction forces-derived loading values, which account for lifetime physical activity affecting bone health. Previous studies report that the total BPAQ score was a stronger predictor of bone strength and geometry as well as areal bone mineral density; however, its relations to a radial quantitative ultrasound-assessed speed of sound (SOS in m/s) has not been well studied in healthy young adults. PURPOSE: The purpose of this cross-sectional study was to determine if bone-loading physical activity was positively related to a radial SOS in healthy young adults. METHODS: Ninety-five healthy participants, 45 women (21.6 ± 2.3 years, 162.9 ± 6.5 cm, 61.1 ± 11.7 kg) and 50 men (21.1 ± 1.9 years, 176.3 ± 8.0 cm, 78.8 ± 14.1 kg), were recruited for this study. The BPAQ scores (current, cBPAQ-previous 12 months; past, pBPAQ-from one year of age to the current age; total, tBPAQ-average of pBPAQ and cBPAQ) were used to obtain a comprehensive account of lifetime physical activity related to bone health. We measured the SOS at one-third distal radius of the nondominant hand using a radial QUS system. Body composition was estimated by bioelectrical impedance analysis. RESULTS: Student's t-tests revealed that the radial SOS was significantly higher in young women (4146 m/s) than in young men (4032 m/s) (p<0.001). The pBPAQ and tBPAQ scores were significantly higher in young women than in young men (p<0.001). Pearson's correlations indicated that there were positive associations between pBPAQ (r=0.256, p=0.013), tBPAQ (r=0.273, p=0.008), and the radial SOS for the whole cohort, but sex-specific associations were not found (>0.05). There were no significant associations between cBPAQ and the radial SOS (>0.05). CONCLUSIONS: These data suggest that the tBPAQ score-derived physical activity was a stronger predictor of the radial SOS in healthy young adults. Future studies are needed to further clarify this implication comparing results obtained from objective physical activity assessment tools.