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Abstract

This study designed three different types of sports bras based on the physiological characteristics of female upper bodies. The dressing pressure, skin temperature, and shaping support effectiveness of one subject when wearing those sports bras were evaluated under static and dynamic states. The results indicated that all designed bras illustrated excellent pressure comfort. Regarding the thermal comfort and shaping support performance, sports bras B2 and B3 with further optimizations had improved performances compared to B1. Besides, it was found that the skin temperature would increase with the dressing pressures from sports bras. The increased but comfortable dressing pressure could also benefit the shaping and support performance of sports bras. B2² and B3³ had superior support performance to B1, with excellent ability to lift and gather the breasts, and to retract the waist. In summary, optimized sports bras with a cross, hollowed-out, and split design could effectively meet body comfort needs.

Keywords

Sports bra optimized design pressure comfort thermal comfort shaping support

The pressure provided by sports bras plays an important role in supporting the soft tissue structure of the breasts, reducing breast movement, protecting the breasts from harm, enhancing athletic performance, and shaping an attractive body.¹ In addition, wearing a sports bra is considered to have the further benefits of reducing the risk of breast sagging, increasing confidence, and improving athletic performance.² Therefore, evaluating the functionality, comfort, and safety of sports bras is very important.³ During exercise, the movement of the female chest related to the chest wall and discomfort in wearing bras still affect athletic performance and even restrict participation in sports activities.^4,5 In addition to the shoulder straps and support factors that need to be considered during exercise, another factor related to bra comfort is the size of the bra.⁶ Regardless of whether oversized or undersized, the human body will experience discomfort. Oversized bras lead to underpressure and will decrease exercise efficiency.⁷ Besides, insufficient support could result in breast displacement. Undersized bras lead to overpressure, which hinders physical activities and can cause body swelling and pain, tachypnea, and fatigue.⁸ The pressure generated by sports bras has impacts on dressing comfort. When the pressure from bras exceeds the human body’s limit, it will cause some physiological and psychological effects, including increased rectal temperature, decreased blood flow, constipation, visceral displacement, and organ failure.^9,10 Due to the direct contact and sensitivity between bras and human skin, the pressure exerted by bras on the body varies with breast adipose distribution and movement postures, which can lead to different tactile and pressure sensations.¹¹ Thus, it is important to have a suitable sports bra that can alleviate breast pain, reduce potential tissue damage, reduce embarrassment related to breast displacement, and improve athletic activities.^12,13

Sports bras form a close environment with the human body. However, this additional layer of cloth often causes thermal discomfort during exercise.² The human body dissipates heat through four independent processes: radiation, conduction, convection, and evaporation.¹⁴ Wearing a tight-fitting sports bra will suppress heat dissipation, reduce airflow near the skin, and further reduce the efficiency of the human body in reducing skin temperature through sweating, convection, and heat radiation transmission.¹⁵ Compared with naked breasts, wearing a bra will have negative impacts on thermoregulation, breast skin cooling ability, and thermal comfort after exercise.¹⁶ When evaluating tight and pressure clothes, the core temperature and skin temperature are used to measure the thermoregulation behavior of human bodies.^9,17,18 The skin temperature needs to be maintained within a certain range and depends mainly on human metabolism to generate heat and dissipate heat.¹⁹ When the skin temperature is around 32–34°C, there is a comfortable microenvironment between the skin and the fabric.²⁰ When the skin temperature exceeds 35°C, the heat stored during exercise cannot dissipate, which can lead to skin temperature increase, fever stress, stroke, and even death.^21,22 Therefore, it is important for sports bras to maintain pressure comfort, as well as thermal comfort.

Most current researches about the comfort of sports bras focus on fabric performance, bra drag reduction effects, and the thermal comfort under static states, which are important foundations.^23
–28 However, usages of traditional sports bras are restricted due to poor support and limited comfort, especially for women with large breast sizes.^29,30 Besides, shoulder straps and bra bands are too thin and tight, causing compression and pain to the shoulder and the neck.³¹ Poor fabric breathability and moisture absorption also result in a sticky and stuffy wearing experience.^32
–34 To solve these problems, some researchers improved the style of sports bras, designed wide shoulder straps, and used shoulder pads to cushion pressure, but the effects are not ideal. The usage of widened shoulder straps and shoulder pad materials increases friction and is not conducive to heat dissipation.^35,36 Some researchers explored the dressing pressure of sports bras. Cross-back shoulder straps can bear high pressure, but cannot withstand high levels of pressure (>4 kPa). The maximum pressure for the bra band is 1.47–2.13 kPa.^37,38 Although research references are provided, bras made of different materials and with different performance are not comparable.³⁹ Researchers have also evaluated the physical mechanical and thermal-humid properties of functional sports fabrics, but their applications are limited due to high cost.^40,41 Currently, more female consumers realize the importance of protecting breasts during exercise and put forward higher requirements for bra comfort and functions.⁴² It is believed that reasonable style and structure designs of sports bras can improve sports performance, provide comfort, and protect human body from sports-related injuries.^43
–45 Therefore, it is crucial to choose a sports bra with pressure comfort, thermal comfort, fitting style, and effective support.⁴⁶

The aim of this study was to optimize the design of current sports bras to achieve favorable pressure control, provide skin thermal comfort, and enhance the shaping support effects. We designed three types of sports bras (B1 is the regular style, B2 and B3 are the optimized styles), based on the same fabric. We evaluated the pressure distribution and skin temperature of the human body during static and dynamic exercise states (eight dressing states). Results demonstrated that minimized dressing pressure could promote physical activities and provide aesthetic shaping support effectiveness for female exercisers by optimized bras. It confirmed that optimization of sports bra styles could improve the dressing pressure comfort and thermal comfort, and enhance the shaping support performance efficiently. This study provides promising design strategies for sports bras to fulfill practical needs in this clothing area.

Materials and methods

Fabrics and characterization

Elastic interlocking-stitch fabric made from nylon/spandex 80%/20% yarns by weft knitting was provided by Jinpai Warp Knitting Technology Co., Ltd. The structural parameters, mechanical properties, and thermal-humid properties of the fabric was tested according to FZ/T 70006-2004, GB/T 21655.1-2008, FZ/T 01071-2008, GB/T 12704.1-2009, GB/T 5453-1997, GB/T 11048-2008, and GB/T 16160-2017. Results of the stretch resilience, softness, water absorption rate, wicking height, dripping diffusion time, evaporation rate, water vapor transmission, air permeability, and thermal resistance are shown in Table 1. The experimental environment was a room temperature of 23 ± 2°C, a relative humidity of 50 ± 4%, and an indoor wind speed of <0.1 m/s.

Table 1.
Characterizations of weft knitted fabric

Test indicators Values

Thickness (mm) 0.673

Grams per square meter (g/m²) 200

Transverse density (loops/5 cm) 116

Vertical density (loops/5 cm) 178

Warp/weft stretch resilience (%) 94.4/89.9

Warp/weft softness (cN·cm²/cm) 0.0335/0.0233

Water absorption rate (%) 193

Warp/weft wicking height (mm) 168/145

Drip diffusion time (s) 4.5

Evaporation rate (g/h) 0.21

Water vapor transmission (g/m²·24 h) 8332

Air permeability (mm/s) 83

Thermal resistance (m²·K/W) 0.0118

Design of sports bras

Three types of sports bras were designed based on physiological characteristics of the female upper body structure, as well as the parameters of one subject (Table 2). The design drawing and structural diagrams of the front and back of the sports bras are shown in Figure 1. B1 (Figures 1(a)–(c)) represented the basic style with a simple structure, which was relatively close to the basic pattern of British women's clothing. It had the wide shoulder straps design. The cup is an elliptical cup that wraps around the breasts. No zippers or hooks-buckles were included, which allowed the bra to be worn directly. B2 (Figures 1(d)–(f)) had a horseshoe-shaped shoulder, which was designed to disperse shoulder and neck pressure. The cup is a mango cup that fits snugly against the breasts, reducing shaking and friction and providing a stereoscopic shape. The back of B2 was designed to be a “V” shape to enhance lifting force, distribute pressure, and outline the backline, and it was cross and hollowed out on the back to get rid of stuffiness. The bottom is designed to be a loop shape, protecting privacy during exercise. Three rows of hooks-buckles from small to large (B2¹: 1.5 cm tight, B2²: fitted, B2³: 1.5 cm loose) were set up for flexibly adjusting the girth. B3 (Figures 1(g)–(i)) were designed with crossed double-row shoulder straps, which crossed at the front and separated at the back to prevent the shoulder strips from slipping. The cup is a water drop cup that naturally gathers to create the breast shape. The bottom of the cup is designed to have strong support, resembling a “W” shape. It supports the cup on top and connects to the bottom, providing dual stability and shock resistance during exercise. The bottom of the bra is designed to have a crossing stitching to decorate the waistline and enhance the sense of layering. Wing brackets on both sides were intended to retract the breasts inward, to prevent overflow and dispersion, and to hide excessive fat tissue. There was an integrated connection with the shoulder and back, optimized support, and wrapping. The “I” shaped design of the inner back layer provides stable support and balanced pressure distribution, relieves shoulder and neck fatigue, and does not jam the scapula, so the arm can swing freely. The outer layer of the back is designed to have an “H”-shaped reinforcement layer. Four rows of hooks-buckles were applied on the back top and back bottom to enhance breast support. The sizes from small to large are B3¹ (3 cm tight), B3² (1.5 cm tight), B3³ (fitted), and B3⁴ (1.5 cm loose) to cope with changes in girth during the fat reduction process.

Table 2.
The age, body mass, and main body measurements of the test subject

No. Physical indicators Values

1 Age (years) 30

2 Body mass (kg) 50

3 Body height (cm) 162

4 Shoulder width (cm) 40

5 Upper chest girth (cm) 82

6 Chest girth (cm) 83

7 Lower chest girth (cm) 76

8 Upper waist girth (cm) 69

9 Waist girth (cm) 66

10 Abdominal girth (cm) 77

11 Hip girth (cm) 93

Figure 1.
Design schematics of sports bras: (a) front of sports bra B1; (b) back of sports bra B1; (c) structure of sports bra B1; (d) front of sports bra B2; (e) back of sports bra B2; (f) structure of sports bra B2; (g) front of sports bra B3; (h) back of sports bra B3 and (i) structure of sports bra B3.

Pressure evaluations of sports bras

The pressure measurement points were set in some active parts of the upper body, such as the shoulder, the armpit, the chest, the waist, and the back. The breast pads of bras were also included. In total, 12 points located on the bra body and cup were applied for pressure measurement, as shown in Figures 2(a)–(i).

Figure 2.
Distribution of measuring points of sports bras B1, B2, and B3: (a)–(c) front, side, and back of B1; (d)–(f) front, side, and back of B2 and (g)–(i) front, side, and back of B3.

The experiment was conducted in the Clothing Pressure Comfort Laboratory of Donghua University. One subject entered the lab 30 min in advance to adapt to the environment and to decrease experimental variations. This subject wore sports bras B1, B2, and B3 (eight dressing states) in sequence. The testing processes were as follows. (1) Turn on the instrument switch and adjust it to the initial state. (2) Mark the 12 test points on the subject’s body. (3) The subject was in a naked (N) state and airbag sensors were attached to the 12 test areas in sequence. After stabilizing for 10 min, the static initial values of the sensor display screen were read and recorded. (4) The subject wore B1 and the above steps were repeated. (5) The subject took off B1 and rested for 10 min, then wore B2 and the above steps were repeated. (6) After resting for 10 min, the subject wore B3 and the above steps were repeated. Because B2 and B3 are three row hooks-buckles and four row hooks-buckles sports bras, respectively, the above steps were repeated until each dressing state had been measured.

Thermal comfort evaluations of sports bras

P1, P3, P9, and P12 with a significant increase in pressure were selected for skin temperature testing, as indicated by T1, T3, T9, and T12 in Figure 2. One subject was ran while wearing the sports bras, mimicking exercise in the gym (Figure 3). The experiment was conducted in the Sports Biomechanics Lab of Donghua University, and the subject entered the lab 30 min before running to adapt to the environment. A thermocouple temperature sensor was used to record the skin temperature first in the static state. Then, the skin temperature was recorded during 60 min dynamic running. The test subject wore sports bras B1, B2, and B3 (eight dressing states) for 5 min, respectively, and the skin temperature was recorded during running to evaluate the thermal comfort of human dressing. The run included three stages: (1) prepare (balanced for 30 min); (2) run (run at a speed of 5 km/h for 60 min); and (3) rest (balanced for 10 min).

Figure 3.
One subject wore three sports bras and exercised on a treadmill: (a)–(f) sports bra B1; (g)–(l) sports bra B2; (m)–(r) sports bra B3.

Shaping support effectiveness of sports bras

The experiment was conducted in the Human Body Measurement Lab of Donghua University. We measured the basic dimensions of one subject in a natural upright N state using a Martin measuring instrument and a tape (Figures 4(a)–(f)). In order to protect the privacy of this subject, we used the human body diagram in CLO software as the illustration. We first measured and analyzed the human body size change of the subject before and after wearing the sports bras. Then, the shaping support effectiveness regarding the circumference and breast sizes was evaluated for the three types of sports bras. When the size change was negative, it indicates that wearing the bra reduces the size of the area. When the size change was positive, it indicates that wearing the bra increases the size of the area. When the size change was 0, it indicates that the size before and after wearing had not changed. Fourteen parts of the subject wearing B1, B2, and B3 (eight dressing states) were measured to record their height, width, thickness, girth, and length, as shown in Figure 4 (S1: chest height; S2: lower chest height; S3: upper chest width; S4: chest width; S5: lower chest width; S6: waist width; S7: upper chest thickness; S8: chest thickness; S9: lower chest thickness; S10: upper chest girth; S11: chest girth; S12: lower chest girth; S13: waist girth; and S14: breast point spacing).

Figure 4.
Measurement for body sizes of one subject: (a) measurement of the height of the subject body; (b) measurement of the width of the subject body; (c) measurement of the thickness of the subject body; (d), (e) measurement of the girth of the subject body and (f) measurement of the length of the subject body.

Results and discussion

Pressure comfort

Figures 5(a)–(g) show the dressing pressure of one subject who was N and wearing sports bras B1, B2, and B3 (eight dressing states). When this subject was N, the pressure of P1 and P12 remained stable. However, when wearing types of B1, B2, and B3, the overall dressing pressure showed increased values, especially those of P1, P3, P9, and P12. However, all of them were within the comfortable pressure range. Besides, there was no significant difference between P5 and P11. When wearing fitted sports bras of B1, B2², and B3³, the overall pressure from B1 was higher than that from B2² and B3³, indicating that the pressure comfort was improved after sports bra style optimizations. Among them, B3³ exhibits significant pressure at P1 (1.27 kPa) and P12 (0.77 kPa). The design of crossed double-row shoulder straps and four row hooks-buckles increased the dressing pressure. When wearing B2¹, B2², and B2³, the overall dressing pressure changed stepwisely, with B2¹ > B2² > B2³. Due to a reduction of 1.5 cm in the size of the waist back hooks-buckles in B2¹, the dressing pressure increased, especially at the measurement points of P3 (0.83 kPa) and P9 (1.04 kPa) located at the waist. The waist size was increased by 1.5 cm when wearing B2³, resulting in relatively low dressing pressure. When wearing B3¹, B3², B3³, and B3⁴, the overall pressure also illustrated a change stepwisely, with B3¹ > B3² > B3³ > B3⁴. Due to a 3 cm decrease in the size of the chest back hooks-buckles and waist back hooks-buckles in B3¹, the dressing pressure increased, especially in P1 (1.91 kPa), P3 (1.15 kPa), P9 (1.39 kPa), and P12 (0.91 kPa). As the sports bras were loosened gradually, the dressing pressure decreased. Taken together, the design and optimization of the sports bra style can effectively reduce dressing pressure. A sports bra size decrease and complex structural design would increase dressing pressure, while loose sports bras had low dressing pressure.

Figure 5.
The dressing pressure test and distribution of pressure of one subject: (a) dressing pressure test of B1; (b) dressing pressure test of B2; (c) dressing pressure test of B3; (d) distribution of dressing pressure; (e) the pressure distribution of fitted sports bras; (f) pressure distribution of B2 and (g) pressure distribution of B3.

Thermal comfort

Figure 6 shows the skin temperature of one subject during the static state and dynamic running when wearing sports bras B1, B2, and B3 (eight dressing states). When this subject was wearing fitted bras B1, B2², and B3³ in a static state, the skin temperature of B1 at T1, T3, T9, and T12 was higher than those of B2² and B3³, as shown in Figures 6(a)–(e). We found that although the dressing pressure of B3³ was higher at P1 and P12 than those in B1 and B2², the skin temperatures when wearing B3³ and B2² were similar and lower than that when wearing B1. This indicated that B2² and B3³ were superior to B1 in terms of thermal comfort performance. It was due to the optimized design of the hollowed-out and split design of B2² and B3³, which could effectively form airflow channels and dissipate heat in a timely manner. Figures 6(f) and (g) show the skin temperature when wearing B2 (B2¹, B2², B2³) and B3 (B3¹, B3², B3³, B3⁴). We found that pressure had an impact on skin temperature, but comfort pressure has less impact on temperature. The skin temperature when wearing sports bras with decreased size by 3 or 1.5 cm was higher than that of fitted or increased-size ones.

Figure 6.
Skin temperature during the static state and dynamic 60 min running: (a) static skin temperature of B1, B2², and B3³; (b) T1 skin temperature of B1, B2², and B3³ during the static state; (c) T3 skin temperature of B1, B2², and B3³ during the static state; (d) T9 skin temperature of B1, B2², and B3³ during the static state; (e) T12 skin temperature of B1, B2², and B3³ during the static state; (f) static state skin temperature of B2¹, B2², and B2³; (g) static state skin temperature of B3¹, B3², B3³, and B3⁴; (h) dynamic skin temperature of B1, B2², and B3³; (i) T1 skin temperature of B1, B2², and B3³ during the dynamic state; (j) T3 skin temperature of B1, B2², and B3³ during the dynamic state; (k) T9 skin temperature of B1, B2², and B3³ during the dynamic state and (l) T12 skin temperature of B1, B2², and B3³ during the dynamic state.

During dynamic running for 60 min, the skin temperatures of three types of sports bras at T1, T3, T9, and T12 are as shown in Figures 6(h)–(l). The skin temperature first increased to the peak after 30 min and then gradually decreased in all groups. The fabric we selected illustrated moisture absorption and quick-drying properties, but had poor breathability. However, after the style design, the bras can meet the thermal comfort needs of the human body. During continuous running, this subject sweated and dissipated heat through evaporation, gradually bringing their skin temperature closer to the comfortable temperature range. When wearing fitted sports bras of B1, B2², and B3³ during running, the skin temperature change trend was similar to during a static state. The skin temperature while wearing B1 was higher than that while wearing of B2² and B3³, regarding T1, T3, T9, and T12 (Figures 6(h)–(l)). We also found that the skin temperature of B2² and B3³ remained within a comfortable temperature range for both static and dynamic running states. Style design can effectively improve the thermal comfort required by the human body, which confirms the effectiveness of our optimization.

Shaping support effectiveness

Table 3 and Figures 7(a)–(i) show the human body size changes of various parts before and after wearing the three types of sports bras (eight dressing states). The parts with reduced sizes focused on S5, S6, S9, S13, and S14. Among them, S14 showed the highest value, with 23.80% of B2¹. The parts with increased sizes focused on S1, S2, S3, S7, S8, S10, and S11, wherein S7 and S10 showed relatively higher values compared to the other parts. B3¹ increased by 10.66% at S7, while B2¹ increased by of 9.38% at S10. According to the results, B2² had the best shaping support performance, with an increase in chest height and girth and a decrease in chest width, breast point spacing, and waist girth. This indicated that B2² had the ability to lift and gather the breasts and retract the waist. The shaping support effectiveness was B2¹ > B2² > B2³. Besides, the shaping support performance of small-size (high-pressure) bras was better than that of large-size (low-pressure) bras. The shaping support effectiveness of B3 was B3¹ > B3² > B3³ > B3⁴. Taken together, the experimental results verified that the optimized bra styles improved the shaping support. Besides, reducing the size (reasonable pressure) could have a positive effect on shaping the support abilities.

Table 3.
Size changes of the human body before and after dressing

Measuring point Size changes in eight dressing states (%)

B1 B2¹ B2² B2³ B3¹ B3² B3³ B3⁴

Height S1 +0.26 +1.32 +0.70 +0.35 +0.35 +0.35 +0.26 +0.18

S2 +2.38 +2.95 +2.57 +2.00 +1.33 +0.76 +0.38 +0.38

Width S3 +5.86 +1.47 +3.30 +5.49 +1.10 +2.20 +5.13 +5.49

S4 –4.90 –0.70 +0.35 +0.70 0 +1.40 +2.10 +3.50

S5 –3.11 –1.56 0 +1.56 –3.11 –1.56 –1.56 +0.39

S6 –2.31 –3.46 –3.08 –3.08 –5.38 –3.08 –2.69 0

Thickness S7 +7.11 +8.12 +7.61 +7.61 +10.66 +10.15 +9.64 +6.09

S8 +1.87 +4.67 +4.67 +1.87 +4.21 +4.21 +2.34 +2.34

S9 +1.07 –0.53 0 +0.53 –2.14 –1.60 –0.53 +0.53

Girth S10 +5.63 +9.38 +7.50 +6.25 +5.63 +5.00 +4.38 +4.38

S11 +1.81 +5.42 +5.42 +4.82 +4.82 +4.82 +3.61 +2.41

S12 –4.70 –3.90 0 +2.60 0 0 +1.30 +2.60

S13 +0.69 –1.80 –0.41 +0.28 –3.18 –1.80 –0.41 +0.97

Length S14 –19.00 –23.80 –19.00 –9.52 –14.29 –11.90 –9.52 –4.76

Figure 7.
Size changes before and after wearing sports bras: (a) size changes before and after wearing B1, B2 (B2¹, B2², B2³), and B3(B3¹, B3², B3³, B3⁴); (b) size changes before and after wearing B1, B2², and B3³; (c) height size changes before and after wearing B1, B2², and B3³; (d) width size changes before and after wearing B1, B2², and B3³; (e) thickness size changes before and after wearing B1, B2², and B3³; (f) girth size changes before and after wearing B1, B2², and B3³; (g) length size changes before and after wearing B1, B2², and B3³; (h) size changes before and after wearing B2¹, B2², and B2³ and (i) size changes before and after wearing B3¹, B3², B3³, and B3⁴.

Conclusion

In summary, we have designed three different types of sports bras based on the physiological characteristics of the female upper body structure. Their pressure comfort, thermal comfort, and shaping support effectiveness were evaluated. B1, B2 (B2¹, B2², B2³) and B3 (B3¹, B3², B3³, B3⁴) have excellent pressure comfort. In addition, the optimized bras B2 and B3 improved the thermal comfort and shaping support performance. Reducing the sports bra sizes and including complex structures can increase dressing pressure. During the static and dynamic running states of one subject, the skin temperature was higher when wearing sports bras with decreased size, compared to those when wearing fitted or large sports bras. The skin temperatures of B2² and B3³ are similar and both remain within the comfortable temperature range, indicating that B2² and B3³ have better thermal comfort than B1. In addition, the shaping support effectiveness of sports bras has been improved through optimized design, which is beneficial for sportswomen. The subject who wore three types of sports bras had a certain degree of size changes of in their body. The parts with reduced sizes focused on S5, S6, S9, S13, and S14, while the parts with increased sizes focused on S1, S2, S3, S7, S8, S10, and S11. Besides, the shaping support performance of small-size (high-pressure) sports bras was better than that of large-size (low-pressure) sports bras. The shaping support effectiveness was B2¹ > B2² > B2³ and B3¹ > B3² > B3³ > B3⁴. Among B1, B2², and B3³, B2² has the best shaping support performance, with an increase in chest height and girth and a decrease in chest width, breast point spacing, and waist girth. This indicates that B2² has a good ability to lift and gather the breasts and retract the waist. In summary, it has been shown that the style design of sports bras can improve dressing pressure and skin thermal comfort and effectively enhance the shaping support performance. The fact that optimized design through style provides the pressure comfort, thermal comfort, shaping support, and mutual influence required by the human body cannot be ignored in the research and the development of sports clothing and sports fabrics.

Test indicators	Values
Thickness (mm)	0.673
Grams per square meter (g/m²)	200
Transverse density (loops/5 cm)	116
Vertical density (loops/5 cm)	178
Warp/weft stretch resilience (%)	94.4/89.9
Warp/weft softness (cN·cm²/cm)	0.0335/0.0233
Water absorption rate (%)	193
Warp/weft wicking height (mm)	168/145
Drip diffusion time (s)	4.5
Evaporation rate (g/h)	0.21
Water vapor transmission (g/m²·24 h)	8332
Air permeability (mm/s)	83
Thermal resistance (m²·K/W)	0.0118

No.	Physical indicators	Values
1	Age (years)	30
2	Body mass (kg)	50
3	Body height (cm)	162
4	Shoulder width (cm)	40
5	Upper chest girth (cm)	82
6	Chest girth (cm)	83
7	Lower chest girth (cm)	76
8	Upper waist girth (cm)	69
9	Waist girth (cm)	66
10	Abdominal girth (cm)	77
11	Hip girth (cm)	93

Measuring point	Size changes in eight dressing states (%)
Height	S1	+0.26	+1.32	+0.70	+0.35	+0.35	+0.35	+0.26	+0.18
S2	+2.38	+2.95	+2.57	+2.00	+1.33	+0.76	+0.38	+0.38
Width	S3	+5.86	+1.47	+3.30	+5.49	+1.10	+2.20	+5.13	+5.49
S4	–4.90	–0.70	+0.35	+0.70	0	+1.40	+2.10	+3.50
S5	–3.11	–1.56	0	+1.56	–3.11	–1.56	–1.56	+0.39
S6	–2.31	–3.46	–3.08	–3.08	–5.38	–3.08	–2.69	0
Thickness	S7	+7.11	+8.12	+7.61	+7.61	+10.66	+10.15	+9.64	+6.09
S8	+1.87	+4.67	+4.67	+1.87	+4.21	+4.21	+2.34	+2.34
S9	+1.07	–0.53	0	+0.53	–2.14	–1.60	–0.53	+0.53
Girth	S10	+5.63	+9.38	+7.50	+6.25	+5.63	+5.00	+4.38	+4.38
S11	+1.81	+5.42	+5.42	+4.82	+4.82	+4.82	+3.61	+2.41
S12	–4.70	–3.90	0	+2.60	0	0	+1.30	+2.60
S13	+0.69	–1.80	–0.41	+0.28	–3.18	–1.80	–0.41	+0.97
Length	S14	–19.00	–23.80	–19.00	–9.52	–14.29	–11.90	–9.52	–4.76

Footnotes

Declaration of Conflicting Interests

The authors declared no potential conflicts of interest with respect to the research,authorship,and/or publication of this article.

Funding

The authors disclosed receipt of the following financial support for the research,authorship,and/or publication of this article: This work was supported by the National Key R&D Program of China (No. 2017YFB0309100).

ORCID iD

Peihua Zhang

References

Wakefied-Scurr

Sanchez

Jones

A multi-stage intervention assessing, advising and customising sports bras for elite female British athletes. Res Sports Med 2022; 31: 1–17.

Ayres

White

Hedger

, et al. Female upper body and breast skin temperature and thermal comfort following exercise. Ergonomics 2013; 56: 1194–1202.

Brisbine

Steele

Phillips

, et al. Breast pain affects the performance of elite female athletes. J Sports Sci 2020; 38: 528–533.

Burbage

Rawcliffe

Saunders

, et al. The incidence of breast health issues and the efficacy of a sports bra fit and issue service in British army recruits. Ergonomics 2021; 64: 1052–1061.

McGhee

Steele

JR.

Optimising breast support in female patients through correct bra fit a cross-sectional study. J Sci Med Sport 2010; 13: 568–572.

Mcghee

Steele

JR.

Breast elevation and compression decrease exercise-induced breast discomfort. Med Sci Sports Exercise 2010; 42: 1333–1338.

McGhee

Steele

JR.

Biomechanics of breast support for active women. Exercise Sport Sci Rev 2020; 48: 99–109.

Ocran

Zhai

LN.

A study to evaluate pressure distribution of different sports bras. J Eng Fibers Fabr 2022; 17: 1–15.

Yick

Keung

, et al. Sports bra pressure: effect on body skin temperature and wear comfort. Int J Environ Res Publ Health 2022; 19: 1–16.

10.

Liang

Yip

, et al. Numerical simulation of nonlinear material behaviour: application to sports bra design. Mater Des 2019; 183: 1–25.

11.

Clothing pressure and physiological responses according to boning type of non-stretchable corsets. Fibers Polym 2015; 16: 471–478.

12.

Wakefied-Scurr

Sanchez

Jones

, et al. A multi-phase intervention study of sports bra prescription for elite UK female athletes preparing for the Tokyo Olympics and Paralympics. Res Sports Med 2022; 31: 1–16.

13.

Brisbine

Steele

Phillips

, et al. Breast pain affects the performance of elite female athletes. J Sports Sci 2020; 38: 528–533.

14.

Liu

Ocran

, et al. Effects of ventilation design on thermal comfort performance and breast displacement for sports bras. Text Res J 2023; 93: 519–537.

15.

Atasagun

Okur

Psikuta

, et al. The effect of garment combinations on thermal comfort of office clothing. Text Res J 2019; 89: 4425–4437.

16.

Ayres

White

Hedger

, et al. Female upper body and breast skin temperature and thermal comfort following exercise. Ergonomics 2013; 56: 1194–1202.

17.

Shin

Leung

Han

, et al. Thermal and moisture control performance of different mastectomy bras and external breast prostheses. Text Res J 2020; 90: 824–837.

18.

Leung

Shin

Han

, et al. Ergonomic mastectomy bra design: effect on core body temperature and thermal comfort performance. Appl Ergon 2021; 90: 1–12.

19.

Domenico

Hofmann

Collins

PK.

The role of sports clothing in thermoregulation, comfort, and performance during exercise in the heat: a narrative review. Sports Med Open 2022; 8: 1–25.

20.

Liu

Shin

, et al. Emerging materials and strategies for personal thermal management. Adv Energ Mater 2020; 10: 1–23.

21.

Guo

, et al. Hygroscopic and cool boron nitride nanosheets/regenerated flax fiber material microstructure dual-cooling composite fabric. J Colloid Interface Sci 2023; 633: 489–499.

22.

Waldock

KAM

Gibson

Relf

, et al. Exercise heat acclimation and post-exercise hot water immersion improve resting and exercise responses to heat stress in the elderly. J Sci Med Sport 2021; 24: 774–780.

23.

Awais

Krzywinski

Wolfling

, et al. Thermal simulation of close-fitting sportswear. Energies 2020; 13: 1–13.

24.

Yang

Wang

, et al. Thermal comfort properties of cool-touch nylon and common nylon knitted fabrics with different fibre fineness and cross-section. Industria Textila 2021; 72: 217–224.

25.

Broatch

Brophy-Williams

Phillips

, et al. Compression garments reduce muscle movement and activation during submaximal running. Med Sci Sports Exercise 2020; 52: 685–695.

26.

Atasagun

Okur

Psikuta

, et al. Determination of the effect of fabric properties on the coupled heat and moisture transport of underwear-shirt fabric combinations. Text Res J 2018; 88: 1319–1331.

27.

Cheng

Wang

Zeng

, et al. Intelligent research on wearing comfort of tight sportswear during exercise. J Ind Text 2022; 51: 5145S–5168S.

28.

Hsu

Tseng

Chen

, et al. Effects of compression garments on surface EMG and physiological responses during and after distance running. J Sport Health Sci 2020; 9: 685–691.

29.

Liu

Zhang

Zhu

, et al. An analysis of influence factors of sports bra comfort evaluation based on different sizes. J Text Inst 2019; 110: 1792–1799.

30.

Chen

Gho

Wang

, et al. Effect of sports bra type and gait speed on breast discomfort, bra discomfort and perceived breast movement in Chinese women. Ergonomics 2016; 59: 130–142.

31.

Bowles

Steele

JR.

Effects of strap cushions and strap orientation on comfort and sports bra performance. Med Sci Sport Exercise 2013; 45: 1113–1119.

32.

Zhang

, et al. Respiratory mucosa-inspired “sticky-slippery coating” with transparency and structure adaptation based on comb-polymer nanogel. Chem Eng J 2023; 452: 1–9.

33.

Zhao

Tong

Song

, et al. Preparation and characterization of phase change polyester fiber. Integrat Ferroelectr 2022; 228: 238–248.

34.

Liang

Cong

Dong

, et al. Size prediction and electrical performance of knitted strain sensors. Polymers 2022; 14: 1–13.

35.

Norris

Blackmore

Horler

, et al. How the characteristics of sports bras affect their performance. Ergonomics 2021; 64: 410–425.

36.

Bowles

Steele

Munro

BJ.

Features of sports bras that deter their use by Australian women. J Sci Med Sport 2012; 15: 195–200.

37.

Coltman

McGhee

Steele

JR.

Bra strap orientations and designs to minimise bra strap discomfort and pressure during sport and exercise in women with large breasts. Sports Med Open 2015; 1: 21–28.

38.

Umemoto

Ueno

Matsumura

, et al. Ex vivo and in vivo assessment of the non-linearity of elasticity properties of breast tissues for quantitative strain elastography. Ultrasound Med Biol 2014; 40: 1755–1768.

39.

Liu

Miao

Dong

, et al. Enhancing pressure comfort of a bra's under-band. Text Res J 2018; 88: 2250–2257.

40.

Ocran

Zhai

LN.

The impact of sports bra features on measured and perceived pressure for torso movement of the upper body. J Eng Fibers Fabr 2022; 17: 1–12.

41.

Liang

Yip

, et al. Computational modelling methods for sports bra–body interactions. Int J Clothing Sci Technol 2020; 32: 921–934.

42.

Zhou

SP.

Identifying effective design features of commercial sports bras. Text Res J 2013; 83: 1500–1513.

43.

Navalta

Ramirez

Maxwell

, et al. Validity and reliability of three commercially available smart sports bras during treadmill walking and running. Sci Rep 2020; 10: 1–9.

44.

Cheng

Wang

Zeng

, et al. Research on sensory comfort of tight-fitting sportswear based on intelligent models. J Eng Fibers Fabr 2021; 16: 1–15.

45.

McGhee

Steele

Zealey

, et al. Braebreast forces generated in women with large breasts while standing and during treadmill running: implications for sports bra design. Appl Ergon 2013; 44: 112–118.

46.

Norris

Blackmore

Horler

, et al. How the characteristics of sports bras affect their performance. Ergonomics 2021; 64: 410–425.

Measuring point		Size changes in eight dressing states (%)
Measuring point		B1	B2¹	B2²	B2³	B3¹	B3²	B3³	B3⁴
Height	S1	+0.26	+1.32	+0.70	+0.35	+0.35	+0.35	+0.26	+0.18
Height	S2	+2.38	+2.95	+2.57	+2.00	+1.33	+0.76	+0.38	+0.38
Width	S3	+5.86	+1.47	+3.30	+5.49	+1.10	+2.20	+5.13	+5.49
	S4	–4.90	–0.70	+0.35	+0.70	0	+1.40	+2.10	+3.50
	S5	–3.11	–1.56	0	+1.56	–3.11	–1.56	–1.56	+0.39
	S6	–2.31	–3.46	–3.08	–3.08	–5.38	–3.08	–2.69	0
Thickness	S7	+7.11	+8.12	+7.61	+7.61	+10.66	+10.15	+9.64	+6.09
	S8	+1.87	+4.67	+4.67	+1.87	+4.21	+4.21	+2.34	+2.34
	S9	+1.07	–0.53	0	+0.53	–2.14	–1.60	–0.53	+0.53
Girth	S10	+5.63	+9.38	+7.50	+6.25	+5.63	+5.00	+4.38	+4.38
	S11	+1.81	+5.42	+5.42	+4.82	+4.82	+4.82	+3.61	+2.41
	S12	–4.70	–3.90	0	+2.60	0	0	+1.30	+2.60
	S13	+0.69	–1.80	–0.41	+0.28	–3.18	–1.80	–0.41	+0.97
Length	S14	–19.00	–23.80	–19.00	–9.52	–14.29	–11.90	–9.52	–4.76