Problem Statement
Compression garments (CGs) significantly enhance training and competition performance by reducing fatigue Research, including a study by Born et al (2014), has shown that athletes experience improved performance in repeated sprints when wearing CGs Additionally, CGs have been linked to increased upper body strength, further underscoring their benefits in athletic contexts.
A study by Morrison et al (2014b) found a 5% improvement in both concentric and eccentric contractions when using compression garments (CGs) Additionally, Hsu et al (2017) reported that wearing CGs during distance running led to significantly higher median frequency and lower muscle activation in key muscles, suggesting that CGs can enhance muscle function, reduce fatigue, and improve overall running performance.
Compression garments (CGs) can enhance athletic performance by reducing fatigue and impact accelerations during activities like running, as noted by Chin-Yi et al (2016) and Lucas-Cuevas et al (2015) They may lower the risk of sports injuries and decrease muscle activation levels during prolonged activities, thereby conserving muscle force for stability, which can improve overall performance (Wang et al 2014) Research has shown that CGs can lead to significant improvements, such as increased countermovement jump height, decreased perceived exertion, and enhanced comfort after exercise For instance, Rugg & Sternlicht (2013) found that lower-limb CGs helped maintain muscle power during endurance running compared to non-CGs Additionally, Pearce et al (2009) reported that upper body CGs improved performance in tracking tasks by reducing tracking errors, highlighting their beneficial effects on functional motor control However, some studies still indicate mixed results regarding the efficacy of CGs.
3 significant results in performance or physiological responses (Barwood et al 2013; Dascombe et al 2013) Therefore, the underlying mechanisms by which the impacts of CGs on performance remain unclear
Pressure significantly influences the effects of CGs on wearers, with the size of the CGs playing a crucial role in determining the pressure level Despite this, there is still a lack of research regarding the recommended sizes of CGs and the optimal pressure for their use (MacRae, Cotter & Laing 2011).
Research has shown a significant relationship between cardiovascular function and athletic performance and recovery, with heart rate variability (HRV) linked to lower risk profiles and fewer risk factors (Thayer, Yamamoto & Brosschot, 2010) Additionally, ECG signals provide critical parameters such as TpTe, QRS, ST, QT, and corrected QT (QTc), beyond just HRV Studies have indicated that prolonged QTc intervals are associated with an increased risk of cardiac arrhythmias (Felix & Dimitriu, 2011b) Furthermore, longer QTc dispersion has been shown to negatively impact athletes' performance during training (Mandyam et al., 2012).
QT interval was associated with an increase in stroke and incidence of atrial fibrillation (Benn et al 2013)
There was a reduction in muscle activation during a test which was responsible for metabolism and brain oxygenation in a maximal protocol The decreased cerebral
Oxygenation may be linked to limiting activity capacity and increasing central fatigue (Rasmussen et al 2010) Research on the impact of acute exercise on EEG suggests that such physical activity can affect mood and brain function in both elderly and younger individuals (Moraes et al 2011) A systematic review of 17 studies found that fatigue leads to increased slow wave activity in the alpha 1 and 2 bands and theta across the cortex (Craig et al.).
Research indicates that pedalling exercises activate the serotonergic system and increase alpha band activity in the ventral prefrontal cortex, leading to adverse mood changes (Fumoto et al 2010) EEG excitation correlates with mood variations, revealing a fundamental mechanism of cortical activity influenced by varying exercise intensities (Schneider et al 2009) Notably, significant shifts in brain wave activity are linked to fatigue conditions (Craig et al 2012) This study aims to investigate the effects of different sizes of CGs on cardiovascular function and to assess changes in brain activity during a treadmill running test with CG application.
Thesis Contribution
The research aims to investigate the optimisation of performance by the application of compression garments based on biosensors The contributions of this thesis can be summarized as follows:
1 The relationship between compression garments and body effects on sports activity was comprehensively investigated, which had been applied to demonstrate the impacts on performance
2 By utilizing wearable sensors, during and post-exercise, two major physiological signals, electrocardiogram (ECG) and electroencephalography (EEG), captured and analysed, which provided an efficient way to evaluate the influence of compression garments
3 This research proposed, examined, and verified the underlying mechanism of cardiovascular function wearing CGs during the exercise and recovery phase by analysing ECG signals
4 Results from theoretical and experimental analysis, ECG signal is an important parameter to assess cardiovascular performance The heart response from the normal activity in a regular heartbeat can reflect some major features Moreover, the intervals in the ECG signal also indicate the electrical activity according to the current state of the heart during a ventricular contraction
5 Based on the effects of ECG signals, the relationship between the applications of compression garments on cardiovascular function has been investigated Specifically, the research revealed the effects of compression garments on heart rate and QTc during the exercise
6 The proposed hypothesize that wearing CGs would result in less fatigue has been statistically verified based on well-designed experiments It is clear that EEG excitation was associated with mood which indicated an elemental
Research indicates a connection between exercise intensity and changes in brain wave activity, particularly in relation to fatigue (Schneider et al., 2009; Craig et al., 2012) However, there is a lack of studies exploring the impact of compression garments (CGs) on brain activity through EEG signals in sports This study investigates the alterations in brain activity while subjects perform a treadmill running test while wearing CGs, concluding that the use of CGs may lead to reduced fatigue.
Thesis Outline
To achieve the above-mentioned objectives, the thesis consists of six chapters that are organized as follows:
Chapter 1-Introduction This chapter introduces the background information, purposes, contribution and outline of the thesis The background of the research problem gives the objectives of this research project Its engineering significances are pointed out The works that were carried out to achieve the project objectives are listed Chapter 2-Literature Review This chapter is a systematic review and meta-analysis of 96 research articles using the RevMan statistical software package The contents included the introduction of compression garments, application of compression garments, properties, and characterization of compression garments, physiological and
7 physical effects of compression garments, compression garments, and exercise, the pressure of compression garments, biosensors in sports
Chapter 3- This chapter indicates the effects of compression garments on cardiovascular function on the exercise by ECG This chapter includes the examination of the application of compression garments during training on cardiovascular function based on the analyzing of ECG signals Eight young and healthy non-athletes, including five men and three women, volunteered for the study The research study revealed the effects of compression garments on heart rate and QTc during the exercise
Chapter 4- This chapter shows the effects of compression garments on cardiovascular function on recovery by ECG This research study investigated the effects of compression garments during recovery phase following the ECG data collection Fourteen healthy participants took part in the protocol Statistical analysis indicated a significant difference between compression garments group and non- compression garments group at the end of the recovery phase
Chapter 5- Effects of compression garments on EEG This chapter illustrated the relationship between compression garments and brain activity by EEG signals analysis Ten subjects participated in a running test on a treadmill with compression garments and without compression garments EEG electrodes were applied on subjects during the protocols The results demonstrated compression garments have effects on brain activity during the exercise
Chapter 6-This chapter includes a conclusion and future work This chapter synthesizes the findings of the thesis Clinical implications are discussed concerning
This chapter discusses the significance of stability and proprioception in rehabilitation and contemporary sports activities It summarizes the thesis contributions, outlines potential future research avenues to build on these findings, and highlights key results from the study Additionally, it offers recommendations for further exploration of compression garments and biosensors in the realm of sports.
Thesis Notes
This thesis comprises distinct chapters interconnected by shared themes, as illustrated in Figure 1.1 Each of the three main chapters employs a unified methodology and begins with a concise executive summary, akin to an abstract for potential publication References are formatted according to the Harvard_UTS style and are provided at the conclusion of each chapter.
Figure 1 2: Overall works of the experiments in the main chapters
Thesis Publications
The study by Thi Nhu Lan Nguyen, David Eager, and Hung Nguyen, presented at the Third IASTED International Conference on Telehealth and Assistive Technology in Switzerland in 2016, investigates the impact of whole body compression garments on cardiovascular function through ECG signal analysis The findings highlight the potential effects of these garments on heart health, emphasizing their relevance in telehealth and assistive technology applications.
[2] Thi Nhu Lan Nguyen, David Eager, Hung Nguyen, "The effect of compression garments on wearers using biosensors," Australian Biomedical Engineering Conference (ABEC), Australia, 2016, A86
The study by Thi Nhu Lan Nguyen, David Eager, and Hung Nguyen, presented at the 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society in 2018, investigates the impact of compression garments on cardiovascular function during the recovery phase The findings, detailed in the conference proceedings, highlight the potential benefits of using compression wear to enhance cardiovascular recovery.
A study by Thi Nhu Lan Nguyen, David Eager, and Hung Nguyen, presented at the 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society in 2018, examined the effectiveness of compression garments on electroencephalogram (EEG) readings during running tests The findings, detailed on pages 3032-3035 of the conference proceedings, contribute valuable insights into the impact of compression wear on athletic performance and neurological responses.
[5] Thi Nhu Lan Nguyen, David Eager, Hung Nguyen, "The relationship between compression garments and electrocardiogram signals during exercise and recovery phase," Journal of Biomedical Engineering OnLine (Revised)
[6] Thi Nhu Lan Nguyen, David Eager, Hung Nguyen, "The biomedical effects of compression garments during a running protocol," British Journal of Sports Medicine (Submitted)
Introduction
This review aims to explore the literature on compression garments (CGs), focusing on their properties, characterization, applications, and physiological effects It examines the impact of CGs on exercise performance and recovery, as well as the pressure exerted by these garments and the underlying mechanisms involved A comprehensive computerized search was conducted across four online databases—Google Scholar, Web of Knowledge, Web of Science, and Medline (PubMed)—covering publications from 2006 to 2018 Key search terms were utilized to identify relevant studies.
Compression garments, including stockings, clothing, and tights, play a crucial role in enhancing performance and recovery strategies for athletes These compressive items help mitigate exercise-induced muscle damage and improve heart rate variability, contributing to overall cardiovascular health By incorporating compression wear into post-exercise routines, individuals can optimize their recovery and performance outcomes, supported by data from ECG and EEG monitoring.
The literature review highlights the significant influences of compression garments (CGs) on sports performance, focusing on key parameters such as their application in therapy and training, properties, and physiological impacts It outlines the various types of CGs, their sizing, and fabric composition The physiological effects measured include thermoregulatory responses, cardiovascular metrics, and muscle function indicators like fatigue and damage Furthermore, the review emphasizes the effectiveness of CGs in enhancing athletic performance across various sports, improving power output, and facilitating recovery by reducing recovery time and enhancing subsequent performance.
15 measures) The pressure of compression garments has been reported the measurement of provided pressure, a comparison between the influences reported and the pressure delivered
Research was based on the following criteria: (1) subjects wore control clothing or compression garments randomly; (2) the study included many other kinds of exercise;
The research participants were free from any metabolic, cardiovascular, or musculoskeletal disorders and included both males and females from various training backgrounds The study examined the duration of compression garment usage, whether worn during the experiment, post-activity, or both, and included a variety of compression garments It compared multiple types of compression garments (CGs) against non-CGs and evaluated their effectiveness under different temperature conditions Additionally, the research involved participants wearing compression garments on one limb while the other limb remained without Any studies that did not meet these criteria were excluded from the research.
(1) participants received multiple treatments on the experimental group; (2) there was insufficient data; (3) participants were patients; (4) subjects had any metabolic, cardiovascular, or musculoskeletal disorder
Abstracts and titles of papers were assessed by the abovementioned search strategy All full text was peer-reviewed, and all tests were classified Exclusion and inclusion
A total of 16 criteria were utilized to select experiments suitable for the meta-analysis based on full publication content After evaluating 53,200 results from the database search, 30,100 publications were excluded through inclusion criteria and abstract screening Ultimately, 190 papers published since 2006 focusing on "compression garments" were identified, but 94 of these were deemed not relevant to the inclusion criteria Consequently, only 96 reviews were included for the meta-analysis.
Figure 2 1: Selection process and search strategy based on excluded and included publications
The mean value (Mean) and standard deviation (SD) were extracted from all included publications, with some values calculated from tables, graphs, or figures Data not represented in these formats or not reported in publications were excluded from the analysis In instances where results were presented with mean and standard error (SE), the data were illustrated using SE parameters.
Data analysis was conducted using RevMan (Review Manager version 5.3) from The Cochrane Collaboration, specifically The Nordic Cochrane Centre in Copenhagen A fixed-effect model was utilized for the review, with effect sizes categorized as large (greater than 0.7), moderate (0.4 to 0.7), and small (less than 0.4) Standardized mean differences were evaluated using Hedges’ g with a 95% confidence interval The I² parameter was used to indicate heterogeneity, reflecting the percentage of variability across the studies A significant difference was determined when the p-value was below 0.05.
Compression garments
Since the 19th century, compression garments have been widely used in therapy, with historical evidence of bandages aiding venous disease dating back to 450-350 BC The introduction of elasticated stockings in the mid-1880s, stemming from the discovery of elastomeric fibers, marked a significant advancement in this field Research indicates that wearing compressive clothing can enhance muscle performance and promote blood circulation, highlighting the numerous benefits of compression therapy.
Reduction of the symptoms related to venous disease (Weller 2007)
There was an enhancement of scar appearance and lessening of scar size (Wienert 2003)
The ability to absorb exudate fluid from injury (Thomas, Fram & Phillips
Compression can be achieved through two primary methods: traditional bandaging techniques and medical elastic compressive stockings (MECS) These methods can be further categorized into elastic and inelastic options Inelastic bandages, which maintain low resting pressure, can be worn continuously for 24 hours In contrast, elastic compressions must be removed after 24 hours due to the buildup of pressure from high resting compression.
Traditional bandaging techniques and medical elastic compression stockings are essential in treating lymphatic and venous disorders, as well as hypertrophic scarring (Demczyszak et al 2017).
Compression therapy is a non-surgical treatment that applies pressure to specific areas of the body, limiting the flow of nutrients, blood, and oxygen to scar tissue, which in turn reduces collagen production This pressure aids in the realignment of collagen bundles and prevents excess collagen accumulation, thereby diminishing the appearance of scars Numerous studies have demonstrated the effectiveness of compression therapy in healing hypertrophic scars, indicating that it can significantly minimize their development, particularly after severe burns Additionally, it has been noted that this method can prevent scar formation in infants with pulmonary issues on the thorax.
Compression therapy has demonstrated beneficial effects not only on hypertrophic scars but also on various other conditions It is effectively used in the treatment of issues arising from long and microgravity flights, as well as in preventing ulcers, edema during pregnancy, thromboembolic events, and deep vein thrombosis (DVT) Applying appropriate pressure to affected areas can mitigate tourniquet effects and prevent vein or capillary occlusion Additionally, compression garments and bandaging have been shown to alleviate edema in pregnancy by enhancing lymphatic fluid flow and improving blood circulation in arteries and veins.
21 which leads to the positive effects in lymphatic drainage, venous pumping, and edema problem
Wearing compression garments has been shown to benefit the healing of venous disease, with studies indicating that they result in fewer adverse effects compared to sclerotherapy (Blọttler & Zimmet 2008; Leopardi et al 2009) Research by Leopardi in 2009 found that compression methods were both effective and safe Additionally, a study on varicose veins revealed that compression therapy maintained its effectiveness over two years (Leung 2010) Given the positive outcomes from various studies, including improved recovery rates in surgical patients (Miller 2011; Miyamoto et al 2011), the use of compressive garments remains a common and beneficial approach in medical treatment.
Inelastic bandages are designed for short-term use, providing low pressure and limited adaptability to the leg, which can lead to discomfort after a few hours (Moffatt 2008; Ramelet 2002) In contrast, long-stretch elastic bandages offer a more flexible structure, allowing for extended wear, although they may result in lower comfort levels (Weller 2007; Ramelet 2002) Medical Compression Stockings (MECS) are available in various pressure levels ranging from 10 mmHg to 49 mmHg, catering to the specific needs of wearers and treatment requirements (Van Geest, Franken & Neumann 2003).
Figure 2 3: Inelastic bandage (left) and elastic bandage (right)
Patients with specific needs for wearing Medical Compression Stockings (MECS) can be accommodated based on individual measurements MECS come in various classifications, and research by Ramelet highlights that some patients find it challenging to wear higher compression garments To assist with this issue, devices such as stocking donnners are available to facilitate easier application of MECS.
Compression therapy is primarily administered through MECS and bandages in medical practice In the early 1970s, alternative compression garments began to be utilized for treating hypertrophic scarring and burns.
(Wienert 2003) There are many forms of compressive clothes involving hand gloves, face masks, chin straps, arm sleeves, boleros, and bodysuits for wearing during a 24- hour period a day
Figure 2 5: Hand gloves, face masks, chin straps, arm sleeves, boleros, and bodysuits
The rising participation in sports has led to a surge in the popularity of performance clothing and sportswear, highlighting the need for further research into innovations that focus on injury prevention and performance enhancement (Wang, Zhang & Zhang 2014) Recently, compression garments have gained traction among athletes, who believe these items can improve athletic performance and aid in recovery (Scally 2015).
Compression garments play a vital role in sports, encompassing a variety of options for both the upper and lower body Upper body choices include full-long sleeve tops, short sleeve tops, and sleeveless tops, while lower body options feature full-leg pants, shorts, and quarter pants Additionally, athletes can benefit from arm sleeves, calf sleeves, and compression socks to enhance performance and recovery.
Figure 2 6: Upper body compression garments (full-long sleeve top, short-sleeve top and without sleeve top)
Figure 2 7: Lower-body compression garments (long-leg pants, quarter pants, short pants)
Figure 2 8: Arm sleeves, calf sleeves, compression socks
Properties and characterization of CGs
Compression garments apply pressure to the trunk and limbs through their elastic properties, utilizing materials such as elastic fabric and synthetic fibers The most commonly used material in these garments is synthetic fiber, primarily composed of polyurethane Additionally, clinical-related compression garments are made from elastic fabrics that include elastodiene and polyamide.
Figure 2 9: Fibres made by chemical synthesis are called synthetic fibres
(polyester, nylon); Elastic fibre elongates under stretching force
The quality standards of compression garments are determined by various factors, including durability, lightweight design, moisture absorbency, pressure application, optimal stretch and fit, comfort level, and skin contact optimization Researchers have referred to compression garments as the "second skin" due to these characteristics (Duffield & Portus 2007a; Kraemer et al 2010; Y 2006).
Many customers express dissatisfaction with garment sizes due to significant variations across different stores and brands (Otieno 2008) Research indicates that companies often focus on a limited range of sizes to meet the needs of a select group rather than the broader population (Loker 2007) While 3D body scanning and anthropometric studies have been employed to streamline body measurement processes, these methods can be time-consuming and expensive (Loker 2007; Otieno 2008) Furthermore, variations in size preferences exist across generations, genders, and races Although custom-made garments can achieve a perfect fit, such solutions are impractical for mass markets due to their associated costs and time requirements (Loker 2007).
Compression garments, including base layers and stretch fabrics, vary in size due to fiber characteristics The high extensibility of stretch materials can complicate sizing, often resulting in patterns designed smaller than actual body sizes for a better fit Interestingly, research indicates that diverse body shapes can wear the same size top because of the fabric's significant elasticity Proper fabric selection is crucial for achieving the desired fit and function in compression garments.
28 plays an essential role in the production; otherwise, the progress may set back to early stages (Xiu-qin 2013)
Research shows that fabric characteristics significantly impact garment size and fit, which can be evaluated using methods like Fabric Assurance by Simple Testing (FAST) and the Kawabata Evaluation System for Fabrics (KES-F) (Yanmei, 2007) These tests help predict fitting issues before pattern making, potentially reducing costly adjustments The FAST and KES-F analyses are enhanced by a computer system developed by McLoughlin and Hayes, which calculates test results efficiently Additionally, the Fabric Sew-ability System provides fabric fingerprints and written material analyses, enabling objective testing without the need for an experienced technician, thus streamlining the process of assessing fabric handle (McLoughlin & Hayes, 2011).
Wearing correctly sized compression garments (CGs) is essential for patients, as highlighted by researchers like Watkins (2010) Miller's study (2011) emphasized the need for a standardized method to measure arms and legs, ensuring patients receive properly fitted garments Incorrect fit can lead to discomfort and ineffective compressive therapy due to inaccurate pressure values Therefore, it is recommended that patients be measured prior to surgery to optimize post-operative outcomes.
29 operative compression garments, excluding when a significant difference in size or body shape is predicted (Watkins 2010)
Research on how shape and body size affect pressure distribution is limited, with previous studies showing inconclusive results regarding garment sizes (Fan & Chan 2005) Recent investigations have shifted focus to the advantages of custom-made garments, which can target pressure application to specific body areas for individual wearers In contrast, improperly sized garments can hinder performance and functionality (Miller 2011).
Previous research investigated the impact of washing on the pressure of compression garments through various methods, including machine washing, hand washing, and washing with moisturizers and detergents (Macintyre 2007) The study found that the pressure exerted by the garments significantly decreased after just 5 minutes of wear, and the extension of elastic fabrics contributed to a notable loss of pressure Additionally, repeated washings resulted in a more significant reduction in pressure, while the use of moisturizer had minimal effect on preserving garment pressure Comparatively, machine washing and hand washing showed no significant difference in their impact on garment performance.
Compression garments can have their pressure levels adjusted by altering the type of elastic fabrics used or by modifying the reduction factor Additionally, employing double or multi-layer construction can further enhance the pressure applied by these garments.
A study conducted in 2006 revealed that using a double-layer bandage can nearly double the pressure compared to a single-layer bandage This finding suggests that increasing the number of fabric layers can enhance the pressure exerted by compression garments However, further research is needed to fully understand the potential benefits of multi-layer compression garments (Macintyre & Baird 2006).
Recent studies indicate a variety of compression garments are utilized in sports activities, yet there is limited information on the pressure range exerted during these activities compared to compression therapy Each study has calculated pressure levels specific to different areas, with summarized results presented in Figure 2.10 and Table 2.1.
Figure 2 10: Position of measurement in pressure
Table 2 1: Pressure of compression garments applied in previous studies (mmHg)
Chest Waist Torso Hip Thigh Knee Calf Ankle
(Sear et al 2010a) Whole body CGs 7.3 5.8 5.3 5.9 9.2 13.1 15.1 17.8
(Piras & Gatta 2017) Whole body CGs 10 13 6 5 8 15
(Dascombe et al 2013) Upper body CGs 5-7 5-7
(Kim, Kim & Lee 2017) Arm sleeves CGs 5-10
(Rider et al 2014) Beneath the knee
(Reed et al 2017) Full lower body
(Hsu et al 2017) Full lower body
(Venckūnas et al 2014) Lower body CGs 17-18 17-18
(Born et al 2014) Lower body CGs 18.3 17.5-
(Born et al 2014) Lower body CGs 20.2 18.2-
(Rugg & Sternlicht 2013) Lower body CGs 7.2 12.6 18
(Driller & Halson 2013b) Full lower body
(Barwood et al 2013) Lower body CGs 11 20
(Hamlin et al 2012b) Full leg length
(Burden & Glaister 2012) Lower body nomionized CGs
(Goh et al 2011) Lower body CGs 8.6 13.6
(Dascombe et al 2011) Lower body CGs 13.7 13.7
(Scanlan et al 2008) Full length lower body CGs
(Upton, Brown & Hill 2017) Lower limb CGs 8.5 14
(Driller & Halson 2013a) Lower body CGs 11.8 20.5
(Hamlin et al 2012b) Full leg length
(Lovell et al 2011) Full lower body
(Webb & Willems 2010) Lower limb compression tights
(Rimaud et al 2010) CGs stocking 22 12
(Vercruyssen et al 2017) CGs stocking 13 18
(Lucas-Cuevas et al 2015) CGs stocking 21 24
(Ali, Creasy & Edge 2011) CGs stocking
(Ali, Creasy & Edge 2011) CGs stocking
(Ali, Creasy & Edge 2011) CGs stocking
(Kemmler et al 2009) CGs stocking 18-20 24
Physiological and physical effects of CGs
A study by Leicht (2010) found that lower body compression garments (CGs) resulted in a higher core temperature compared to a control group during maximal anaerobic running tests However, other research, such as Barwood (2013), indicated no significant difference in core temperature when using lower-body CGs versus running shorts in high heat conditions Chan, Duffield, and Watsford (2016) reported that full-length CGs showed no significant difference in core temperature compared to non-CGs during four hours of manual exercise In a field-hockey skill test, Heath (2008) found no significant temperature changes between traditional sportswear and CGs Similarly, Houghton, Dawson, and Maloney (2009) observed no difference in body temperature with knee-length CGs versus short-sleeved CGs during cycling exercises Lastly, MacRae et al (2012) demonstrated that various sizes of full-length CGs did not affect body temperature during a 60-minute cycling session.
A study by Morrison et al (2014a) found no significant differences in the supine to standing orthostatic test between normothermia and after passive heating when using compression garments (CGs) versus low compression placebo trousers Furthermore, research by Venckūnas et al (2014) indicated that lower CGs did not lead to a notable change in body temperature during a four-kilometer run and two additional laps at temperatures of 20-22°C with 46-53% humidity.
A meta-analysis of previous studies (Barwood et al 2013; Chan, Duffield & Watsford 2016; Houghton, Dawson & Maloney 2009; MacRae et al 2012; Venckūnas et al 2014) revealed no significant differences in the effects of cooling garments (CGs) on core temperature, with an effect size of ES=0.01 (-0.06, 0.07) and a Chi-squared value of 3.95 (df=4, p=0.41, I²=0%) The overall effect test indicated a z-value of 0.2 (p=0.84), with detailed results available in Table 2.2 and Figure 2.10.
Table 2 2: Summary data for the effects of compression garments on thermoregulatory temperature
Figure 2 11: Forest plot representing a comparison between the use of compression garments and control for the measure of thermoregulatory temperature
Research indicates that there was no significant difference in skin temperature between lower compression garments (CGs) and non-compression garments during three treadmill tests at approximately 35.2°C (Barwood et al 2013) Additionally, CG trousers showed no difference compared to placebo trousers in a supine to stand orthostatic test at normothermia and after passive heating (Morrison et al 2014a) However, other studies revealed significant differences when applying CGs; for example, a study on 30 minutes of repeated-sprint exercise found that the skin temperature of 10 male cricket players was significantly higher at 15 ± 3°C (Duffield & Portus 2007b).
Lower body compression garments (CGs) have been shown to increase skin temperature compared to standard athletic training gear during simulated team games, including 20-meter sprints and peak power tests on a cart dynamometer This study involved 14 male rugby players and was conducted in a controlled laboratory environment with temperatures ranging from 16 to 18°C and 30% humidity (Duffield et al., 2008) Additionally, at colder temperatures of 10°C, the effects of these garments were further observed.
A study by Goh et al (2011) found that 20 minutes of running on a treadmill resulted in higher skin temperatures when participants wore long tights CGs compared to non-CGs Additionally, research by Houghton, Dawson, and Maloney (2009) indicated that short-sleeved CGs and knee-length shorts CGs produced significantly better performance results during cycling trials with 10 hockey participants, compared to a control group wearing long socks and knee-length shorts.
Research indicates that wearing full-length body fitted compression garments (CGs) leads to higher skin temperatures during fixed-load cycling compared to gym shorts (MacRae et al 2012) Additionally, during a 4 km run with two extra 400 m laps, the use of lower CGs resulted in significantly elevated skin temperatures compared to not using CGs (Venckūnas et al.).
A meta-analysis of previous studies (Barwood et al 2013; Duffield & Portus 2007b; MacRae et al 2012) revealed that skin temperature can be significantly influenced by the application of cooling garments (CGs), with an effect size of ES=0.70 (0.50, 0.91) The overall effect was statistically significant, indicated by a z-value of 6.68 (p0.05) Additionally, CGs were associated with elevated blood lactate levels, suggesting adverse effects during their use Notably, CGs did not influence proprioception or sweating sensation, yet they resulted in a significantly lower body mass (p