Objective Evaluation of the Functional Performance of Running Wear by suchenfz

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									   Objective Evaluation of the Functional Performance of Running Wear
               Lei Yao, Ru Lv, Hong Chen, Huang Chao, Ying-Lei Lin, Jun-Yan Hu, Yi Li*

              Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hong Kong
                                   *
                                   Corresponding author: tcliyi@inet.polyu.edu.hk

        Abstract: Physical property of running wear is believed to influence athlete’s performance during high
        intensity exercise and competition. From sports physiology and functional performance of sportswear, it is
        understood that thermal properties of sportswear could influence heat release from human body;
        biomechanical properties of sportswear affect blood circulation and energy expenditure. Properties such as
        light in weight, thin, high heat release capability, moisture management, and specific designed compression
        are regarded to be important in high performance running wear. Based on this understanding, an objective
        evaluation framework is proposed to characterize the functional performance of running wear. This
        framework characterizes the performance of running wear from five aspects, including structural characters,
        thermal function, protection, hand properties and biomechanical function. Further, commercial running wear
        close to skin were purchased from market (including top brands). Their physical properties of the fabric of
        running wear such as weight per unit area, thickness, air resistance, thermal insulation, UPF, moisture
        management properties, hand properties, and biomechanical properties were tested and their functions were
        evaluated.

        Keywords: Running wear; Physical properties; Performance; Evaluation framework.


1. Introduction                                                   dry, and specific designed compression distribution of
                                                                  the sportswear are believed to be important in a high
     With improved living standards and changing life             performance running wear.
style, people want their clothes to be more fashionable               Manufacturers of sportswear always claim that their
and comfortable. People wear performance sportswear               products provide functions such as protection, keeping
not only during sports activity, but also in their daily          cool, keeping warm, moisture management, wind
life. The global market size of performance sportswear            resistance, anti odour, and minimal drag force. All
is currently estimated to be US$6.40bn, and is expected           these functions are familiarize from fabric material,
to reach US$7.6bn by 2014 [1]. Sportswear has the                 structure, finishing, treatment and structure/pattern
fastest sales growth globally. Popular brands such as             design of the sportswear.
Nike, Adidas, Puma, and Mizuno, introduced their                      To well understand the properties of running wear,
performance sportswear highlighting the functions it              based on the understanding of physical, physiological
performs.                                                         and psychological demands of athletes during high
     Performance of athletes is determined or influenced          intensity exercise and competition, this paper proposes
by biomechanics, physiology, nutrition, psychology,               an evaluation framework to objectively test the
medicine, physiotherapy, pedagogy and gene [2, 3]. To             functional properties of running wear, study physical
enhance performance of athletes at cutting into edge,             properties of commercial wear close to skin. Running
sportswear became a hot topic to be studied [4-6].                wear from brands including Nike and Adidas were
Physical property of running wear is believed to                  purchased from market, their performances were
influence athlete’s performance during high intensity             discussed.
exercise and competition. Thermal properties of
running wear could influence heat release from human              2. Objective evaluation framework
body to surrounding atmosphere, and has an impact on
athletes thermal strain; biomechanical properties of                 First of all, physical, physiological and
running wear might affect blood circulation and energy            psychological demands of athletes were studied.
expenditure, influence performance of athletes.                   Linkage between physical properties of running wear
Currently, properties such as light in weight, thin,              and the physical, physiological and psychological
capability of heat release, ability to keep the body skin

doi:10.3993/tbis2009095 www.tbisociety.org


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demands from athletes were reviewed and summarized               fabric influence the hand feeling of the wearer, and
in Fig. 1. Physical properties of sportswear play                biomechanical properties not only impact on hand
multifarious roles in the wearer. It may induce wearer’s         feeling, moreover, it influences deep vein blood flow
physical, physiological and psychological responses.             and muscle pump effect, which may affect on wearer’s
This may be familiarized from fabric’s basic features,           sports performance. UV blocking property can protect
such as weight and thickness, which may be understood            skin from extreme UV exposure. Further, these
as a part of weight of the wearer in sports activities.          properties of fabric induce sensory response of wearer,
Thermal properties of the sportswear, such as air, heat          to generate comfort perception and influence stress
and moisture/water transport properties, manage the              level of the athletes. To summarize, the physical
heat release from our body to external environment,              properties of sportswear may influence performance of
impact on heat strain of wearer during exercise and              athletes from aspects illustrated in Fig. 1.
competition. Mechanical properties of the sportswear




                       Fig. 1. Physical properties of Sportswear and their impact on athletes.

    To scientifically describe the characters of                 Crispness were obtained from KES evaluation system,
sportswear, physical properties of clothing are                  while Prickle was calculated from a equation obtained
classified into five groups:                                     from Dr. Hu’s study [7,8].
    1) Structural characters, which provide basic
information of fabric, such as weight per unit area and
thickness;                                                                                                        (1)
    2) Thermal properties, which provide information
of heat and moisture/water transport characters of               where: EMmean is Tensile strain mean,
fabric, including water vapor permeability, air                  Bmean is Bending B mean,
resistance,     thermal    insulation   and     moisture         MMDmean is Surface MMD mean,
management capacity;
                                                                 RTwarp isTensile Resilience mean.
    3) Protection property which provide information
                                                                     5) Biomechanical properties, which was presented
on protection from UV radiation;
                                                                 by fabric Yong’s modular and hysteresis to describe
    4) Hand properties, which evaluated surface
                                                                 elastic performance of fabric under bi-axial stretched.
properties, compression properties, tensile properties,
                                                                     Testing methods for these properties are listed in
and shearing properties of fabrics, described by indexes
                                                                 Table 1. And a framework to evaluate the physical
such as Stiffness, Fullness and Softness, Crispness, and
                                                                 properties of sportswear is shown in Fig. 2. Each
Prickle. Indexes, Stiffness, Fullness and Softness and




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property is standardized in a scale from 0-1 (minim -            Ys is the standardized property Yi,
maximum).                                                        Yi is the property Y of fabric i,
                                                                 Ymax is the maximum value of Y property,
                                                     (2)         Ymin is the minimum value of Y property.

where:

                       Table 1 Physical property of fabrics and testing methods (instruments)
          No.          Characterization Items                       Test method (instruments)
                 Structure characters
             1   Fabric thickness                     ASTM D 1777 (SDL fabric thickness tester)
             2   Fabric weight per unit area          STM D 3776 (Balance)
                 Thermal properties
             4   Water vapor permeability             ASTM E96 (Balance, wide   -mouse vessels)
             5   Air permeability                     (KES Air-permeability tester)
             6   Moisture management capacity         (Moisture management tester)
             7   Thermal insulation                   (KES thermal LABO II Tester)
                 Protection
             8   UV-blocking property                 AS/NZS 4399 (CARY 300 Conc UV-visible
                                                      spectrophotometer)
               Hand properties
             9 Stiffness
            10 Fullness and softness                   KES hand evaluation system
            11 Smoothness
            12 Prickle
               Biomechanical properties
            14 Bi-Axial tensile properties            (KES Strip Bi-Axial Tensile Tester)


    The first group is structure characters, which               3. Evaluation of commercial running
provides information on fabric weight per unit area, and
thickness. The second group is thermal properties,
                                                                 wear
presents characters of heat insulation and
moisture/water transports from inner surface of fabric           3.1 Material
to outside. The third group is protection capability of
sportswear, which shows the capability of clothing to                Running wears were sourced from market,
protect athletes from UV radiation. The fourth group is          including popular brands, such as Nike, Adidas, and
hand properties, indicating the hand feeling of the              Kiwami. Materials of fabric included polyester, nylon,
sportswear, such as stiffness, fullness and smoothness,          polyamid, and spandex. Most of tested sports garments
smoothness and prickle. The fifth group called                   are made from knitting fabric, including weft knitting
biomechanical properties, suggests the fabric capability         in plain, rib, interlock, and purl structure, and warp
of elasticity, consequently performance of compression           knitting in pillar stitches, tricot lapping, and atlas
of the sportswear. From this evaluation frame work,              lapping structure. Some of running wear fabric was
physical properties of sportswear can be obtained                woven fabric, tensile yarn applied both in warp and
comprehensively.                                                 weft direction.




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                  Technical specification for fabric of sportswear
                Low       Fair     Medium       High    Very High
                                                                                Structural characters
           0                                                             1   Weight per unit area

           0                                                             1   Thickness
                                                                                 Thermal Function
           0                                                             1
                                                                             Water vapor perm eability
           0                                                             1   Air resistance
           0                                                             1   Therm al insulation/Clo

           0                                                             1   Overall moisture m anagement capacity
                                                                                 Protection
           0                                                             1
                                                                             UPF
                                                                                 Hand properties
           0                                                             1   Stiffness

           0                                                             1   Fullness & Softness
           0                                                             1   Smoothness
           0                                                             1   Prickle
                                                                                Biomechanical function
           0                                                             1
                                                                             Elastic modulus foreword warp
           0                                                             1   Elastic modulus return warp
           0                                                                 Elastic modulus foreword weft
                                                                         1
           0                                                             1   Elastic modulus return weft
           0                                                             1   Hysteresis warp
           0                                                             1   Hysteresis weft
                       Fig. 2. Evaluation frame work of physical properties of running wear.


3.2 Evaluation results and discussion                             and competition, which play important role in
                                                                  management of heat strain of athletes. Thermal
    Basic characteristics of the fabric of a commercial           insulation of fabric was distributed from 0 to 0.43 CLO.
running wear, weight per unit area and thickness are              For most commercial running wear, it is around 0.1-0.2
shown in Fig. 3. The weight per unit area of fabric was           CLO (Fig. 3-e), which match thermal insulation
ranged from 50 to 300g/m2. The weight per unit area of            requirements during running even in cold environment.
most fabric is around 150 g/ m2 (Fig. 3-a). The                   Index of moisture management capacity of the fabrics
thickness of fabrics ranges from 0.1 to 1.3 mm, many              is presented in Fig. 3-f. It indicated that commercial
clothes used thin fabric around 0.65 mm thickness (Fig.           running wear provides various moisture management
3-b).                                                             capacity from poor (0.1) to very good (0.8), a lot of
    Thermal properties of the fabric of commercial                fabrics could provide very good moisture management
running wear were illustrated in Fig. (3-c-f). Water              capacity around 0.7. The importance of moisture
vapor permeability (Fig. 3-c) was distributed from 820-           management capacity was getting well recognized and
1700 g/m2/day, peaked around 1000 g/m2/day; with                  hence it became an important index in functions of
strong air permeability, air resistance of the commercial         sportswear.
running wear is very low (Fig. 3-d). This character
promotes heat release during high intensity exercise




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a             b




c         d




e             f




    564
    g                                                                             h




i                                                                          j




                                           Elestic modulus foreward warp



    k                                                                                 l
                      12.5




                      10.0
          Frequency




                       7.5




                       5.0




                       2.5

                                                                                             Mean =0.28
                                                                                          Std. Dev. =0.316
                                                                                                N =46
                       0.0
                             0.00   0.20    0.40   0.60   0.80      1.00   1.20
                                    Elestic modulus foreward warp




        565
                                             Elastic modulus return warp                                                                                        Hysteresis warp at 20%


                     25                                                                                                                20

                                                                                                m                                                                                                 n
                     20
                                                                                                                                       15




                                                                                                                           Frequency
       Frequency




                     15

                                                                                                                                       10

                     10



                                                                                                                                        5
                      5

                                                                                                   Mean =0.18                                                                                        Mean =0.01
                                                                                                Std. Dev. =0.223                                                                                  Std. Dev. =0.011
                                                                                                      N =46                                                                                             N =46
                      0                                                                                                                 0
                          0.00     0.20             0.40          0.60          0.80     1.00                                               0.00   0.01         0.02     0.03      0.04    0.05
                                   Elastic modulus return warp                                                                                            Hysteresis warp at 20%
                                             Elestic modulus forward weft                                                                                    Elestic modulus return weft


                     20                                                                                                              15
                                                                                                o                                                                                                 p
                     15


                                                                                                                                     10
         Frequency




                     10
                                                                                                                         Frequency


                                                                                                                                       5
                      5



                                                                                                   Mean =0.22
                                                                                                Std. Dev. =0.273
                                                                                                      N =46                                                                                          Mean =0.13
                      0                                                                                                                                                                           Std. Dev. =0.123
                                                                                                                                                                                                        N =46
                          0.00   0.20        0.40          0.60          0.80     1.00   1.20
                                                                                                                                       0
                                  Elestic modulus forward weft                                                                              0.00   0.10         0.20     0.30      0.40    0.50
                                                                                                                                                   Elestic modulus return weft

                                                    Hysteresis weft at 20%


                   25
                                                                                                q
                   20
       Frequency




                   15




                   10




                     5

                                                                                                   Mean =0.02
                                                                                                Std. Dev. =0.022
                                                                                                      N =46
                     0
                          0.00    0.02              0.04          0.06          0.08     0.10
                                          Hysteresis weft at 20%

                                                                                Fig. 3. Evaluation of commercial running wear.

     Commercial running wear provided UPF value                                                                           softness were distributed from 2.3-10, where peak
from 10 to 1000 (Fig. 3-g). Some of them can archive                                                                      appears in around 6-8 (Fig. 3-i); it means many
UPF 1000 at which UV radiation will nearly be                                                                             sportswear have stronger fullness and softness feeling.
blocked completely. Due to most of sports activities                                                                      Crispness of fabric are found from 0 to 3.5, where peak
being conducted outdoor, protection from UV radiation                                                                     appears at around 1.5-2 (Fig. 3-j); it means many
needs to be considered in sportswear development.                                                                         sportswear have weak crispness feeling. Sensory of
Based on standard AS/NZS 4399, UPF over 50 can                                                                            prickle was distributed from 3 to 5, while the sensory
provide good protection from UV radiation in our daily                                                                    scale was set from 0-5 (Fig. 3-k); it means many
life. This requirement may need to be modified in                                                                         sportswear provided strong prickle perception.
sportswear as athletes are always exposed to strong                                                                           Elasticity of fabric is widely used in commercial
solar radiation for long time. The hand properties of                                                                     sportswear. From Fig. 3-l-q, Young’s modulus of the
commercial running wear indicate that stiffness was                                                                       commercial sportswear fabrics reaches peak at 0.1-0.2
distributed from 3 to 10 (Fig. 1-h), in many                                                                              GPa both in warp and weft direction. The hysteresis of
sportswear’s stiffness is around 5-6; it means many                                                                       commercial sportswear is arranged from 0.01-0.02 GPa
sportswear have medium stiffness feeling. Fullness and                                                                    both in warp and weft directions (Fig. 3-n and 3-q).




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This shows that most of commercial sportswear fabric          [3] Gaffney GR, Parisotto R. Gene Doping: a review
presented good elastic capability.                                 of performance-enhancing genetics. Pediatric
     It is known that compression therapy to limb                  Clinics of North America 2007; 54(4):807-822.
accelerated the rate of blood velocity in deep venous         [4] Houghton LA, Dawson B, Maloney SK. Effects of
system [9] and improved calf muscle pump [10,11],                  wearing        compression        garments        on
moreover saved energy expenditure [12]. Fabrics with               thermoregulation during simulated team sport
large young’s modulus and small hysteresis were                    activity in temperate environmental conditions.
utilized in commercial sportswear to achieve                       Journal of Science and Medicine in Sport
compression effects on specific part of sportswear.                2009;12(2): 303-309.
                                                              [5] Duffield R, Cannon J, King M. The effects of
4. Conclusions                                                     compression garments on recovery of muscle
                                                                   performance following high-intensity sprint and
    From this study, a comprehensive framework of                  plyometric exercise. Journal of Science and
objective evaluation of functional performance of                  Medicine in Sport. In Press, Corrected Proof.
running wear is proposed, which characterizes                 [6] Pearce AJ, et al. Wearing a sports compression
functions of running wear including structure                      garment on the performance of visuomotor
characters, thermal function, protection, hand                     tracking following eccentric exercise: a pilot study.
properties and biomechanical properties.                           Journal of Science and Medicine in Sport. In Press,
    Further, it was applied to characterize functions of           Corrected Proof.
commercial running wear. Many commercial running              [7] Hu JY. Characterization of sensory comfort of
wear show features of light in weight, thin, high water            apparel products, in Institute of Textiles and
evaporation and air permeability, low thermal                      Clothing. Hong Kong,2006.p. 51-85.
insulation value, high moisture management capacity,          [8] Hu JY, et al. Comparison of Measurements on
high UV blocking capacity, and strong elasticity. Hand             Fabric Tactile Comfort Properties Using Tactile
properties look like need not be highlighted at this               Comfort Tester and KES. In: Textile
stage of sportswear development. However, we found                 bioengineering and Informatics Symposium
the hand properties of sportswear, especially, prickle             Proceedings. Hong Kong,2008.
was not satisfactory, which may significantly influence       [9] Jamieson R, Calderwood CJ, IA G. The effect of
the cutaneous sensation of athletes, which may impact              graduated compression stockings on blood
the comfort perception during exercise and competition.            velocity in the deep venous system of the lower
                                                                   limb in the postnatal period. BJOG: An
Acknowledgments                                                    International Journal of Obstetrics & Gynaecology
                                                                   2007;114:1292-1294.
    We would like to thank The Hong Kong                      [10] Greenfield PJZMCPTWWJBBBLJ. Compression
Polytechnic University for supporting this research                Stockings and Venous Function. Archives of
through project ITP/014/08TP.                                      Surgery 2002;137:1064-1068.
                                                              [11] Agu O, BD, Seifalian AM. Effect of graduated
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