Blount Hannah, Valenza Alessandro, Ward Jade, Caggiari Silvia, Worsley Peter R, Filingeri Davide
ThermosenseLab, Skin Sensing Research Group, School of Health Sciences, The University of Southampton, Southampton, UK.
Sport and Exercise Sciences Research Unit, SPPEFF Department, University of Palermo, Palermo, Italy.
Exp Physiol. 2024 Aug;109(8):1330-1340. doi: 10.1113/EP091850. Epub 2024 Jun 7.
Female development includes significant morphological changes across the breast. Yet, whether differences in breast surface area (BrSA) modify sweat gland density and output remains unclear. The present study investigated the relationship between BrSA and sweat gland density and output in 22 young to middle-aged women (28 10 years) of varying breast sizes (BrSA range: 147-561 cm) during a submaximal run in a warm environment (32 0.6°C; 53 1.7% relative humidity). Local sweat gland density and local sweat rate (LSR) above and below the nipple and at the bra triangle were measured. Expired gases were monitored for the estimation of evaporative requirements for heat balance (E, in W/m). Associations between BrSA and (i) sweat gland density; (ii) LSR; and (iii) sweat output per gland for the breast sites were determined via correlation and regression analyses. Our results indicated that breast sweat gland density decreased linearly as BrSA increased (r = -0.76, P < 0.001), whereas sweat output per gland remained constant irrespective of BrSA (r = 0.29, P = 0.28). This resulted in LSR decreasing linearly as BrSA increased (r = -0.62, P = 0.01). Compared to the bra triangle, the breast had a 64% lower sweat gland density (P < 0.001), 83% lower LSR (P < 0.001) and 53% lower output per gland (P < 0.001). BrSA (R = 0.33, P = 0.015) explained a greater proportion of variance in LSR than E (in W/m) (R = 0.07, P = 0.538). These novel findings extend the known relationship between body morphology and sweat gland density and LSR, to the female breast. This knowledge could innovate user-centred design of sports bras by accommodating breast size-specific needs for sweat management, skin wetness perception and comfort.
女性的发育过程中乳房会发生显著的形态变化。然而，乳房表面积（BrSA）的差异是否会改变汗腺密度和汗液分泌量仍不清楚。本研究调查了22名年轻至中年女性（28±10岁）在温暖环境（32±0.6°C；相对湿度53±1.7%）中进行次最大强度跑步时，BrSA与汗腺密度和汗液分泌量之间的关系。这些女性乳房大小各异（BrSA范围：147 - 561平方厘米）。测量了乳头上方和下方以及胸罩三角区的局部汗腺密度和局部出汗率（LSR）。监测呼出气体以估算热平衡的蒸发需求（E，单位：瓦/平方米）。通过相关性和回归分析确定BrSA与（i）汗腺密度；（ii）LSR；以及（iii）乳房各部位每个腺体的汗液分泌量之间的关联。我们的结果表明，随着BrSA增加，乳房汗腺密度呈线性下降（r = -0.76，P < 0.001），而每个腺体的汗液分泌量无论BrSA如何均保持恒定（r = 0.29，P = 0.28）。这导致LSR随着BrSA增加而呈线性下降（r = -0.62，P = 0.01）。与胸罩三角区相比，乳房的汗腺密度低64%（P < 0.001），LSR低83%（P < 0.001），每个腺体的汗液分泌量低53%（P < 0.001）。BrSA（R = 0.33，P = 0.015）对LSR方差的解释比例大于E（单位：瓦/平方米）（R = 0.07，P = 0.538）。这些新发现将身体形态与汗腺密度和LSR之间的已知关系扩展到了女性乳房。这一知识可以通过满足特定乳房大小对汗液管理、皮肤湿度感知和舒适度的需求，推动以用户为中心的运动胸罩设计创新。
