Effects of graduated compression stockings on skin temperature after running

An exploratory, intra- and interindividual comparison of the deep neural network automatically measured calf surface radiation temperature during cardiopulmonary running and cycling exercise testing: A preliminary study

Non-invasive and contactless infrared thermography (IRT) measurements have been claimed to indicate acute neural, cardiovascular, and thermoregulatory adaptations during exercise. Due to challenging comparability, reproducibility, and objectivity, investigations considering different exercise types and intensities, and automatic ROI analysis are currently needed. Thus, we aimed to examine surface radiation temperature (T_sr) variations during different exercise types and intensities in the same individuals, ROI, and environmental conditions. Ten healthy, active males performed a cardiopulmonary exercise test on a treadmill in the first week and on a cycling ergometer the following week. Respiration, heart rate, lactate, rated perceived exertion, the mean, minimum, and maximum T_sr of the right calf (CT_sr (°C)), and the surface radiation temperature pattern (CP_sr) were explored. We executed two-way rmANOVA and Spearman's rho correlation analyses. Across all IRT parameters, mean CT_sr showed the highest association to cardiopulmonary parameters (E.g., oxygen consumption: r_s = -0.612 (running); -0.663 (cycling); p < .001). A global significant difference of CT_sr was identified between all relevant exercise test increments for both exercise-types (p < .001; η²_p = .842) and between both exercise-types (p = .045; η²_p = .205). Differences in CT_sr between running and cycling significantly appeared after a 3-min recovery period, whereas lactate, heart rate, and oxygen consumption were not different. High correlations between the CT_sr values extracted manually and the CT_sr values processed automatically by a deep neural network were identified. The applied objective time series analysis enables crucial insights into intra- and interindividual differences between both tests. CT_sr variations indicate different physiological demands between incremental running and cycling exercise testing. Further studies applying automatic ROI analyses are needed to enable the extensive analysis of inter- and intraindividual factors influencing the CT_sr variation during exercise to allow determine the criterion and predictive validity of IRT parameters in exercise physiology.

Chronic and Acute Effects on Skin Temperature from a Sport Consisting of Repetitive Impacts from Hitting a Ball with the Hands

Valencian handball consists in hitting the ball with the hands and it may contribute to injury development on the hands. This study aimed to analyze skin temperature asymmetries and recovery after a cold stress test (CST) in professional players of Valencian handball before and after a competition. Thirteen professional athletes and a control group of ten physically active participants were measured. For both groups, infrared images were taken at the baseline condition; later they underwent a thermal stress test (pressing for 2 min with the palm of the hand on a metal plate) and then recovery images were taken. In athletes, the images were also taken after their competition. Athletes at baseline condition presented lower temperatures (p < 0.05) in the dominant hand compared with the non-dominant hand. There were asymmetries in all regions after their match (p < 0.05). After CST, a higher recovery rate was found after the game. The regions with the most significant differences in variation, asymmetries and recovery patterns were the index, middle and ring fingers, and the palm of the dominant hand. Taking into account that lower temperatures and the absence of temperature variation may be the consequence of a vascular adaptation, thermography could be used as a method to prevent injuries in athletes from Valencian handball.

Influence of Upper Footwear Material Properties on Foot Skin Temperature, Humidity and Perceived Comfort of Older Individuals

Studying the in-shoe microclimate of older individuals is important for enhancing their foot comfort and preventing foot diseases. However, there is a lack of scientific work that explores the thermo-physiological wear comfort of older individuals with different footwear. This study aims to examine the effects of upper footwear materials on changes and distributions in the foot skin temperature and relative humidity for older individuals. Forty older individuals are recruited to perform sitting and walking activities under four experimental conditions in a conditioning chamber. The findings indicate that footwear upper constructed of highly permeable mesh fabric with large air holes shows fewer changes in foot skin temperature (ranging from 1.3 to 3.3 °C) and relative humidity (ranging from -13.3 to 5.7%) throughout the entire foot during dynamic walking, as well as higher subjective ratings on perceived thermal comfort when compared to footwear made of synthetic leather and composite layers. The findings serve to enhance current understanding of designing footwear with optimum comfort for older adults.

Central and Peripheral Thermal Signatures of Brain-Derived Fatigue during Unilateral Resistance Exercise: A Preliminary Study

Simple Summary

Fatigue is considered a brain-derived emotion that could impact performance during the execution of physical exercises. Infrared thermography is a valuable technique able to measure the psychophysiological state associated with emotions in a contactless manner. The aim of the study is to test the capability of infrared thermography to evaluate the central and peripheral physiological effect of fatigue through facial skin and muscle temperature modulations collected during the execution of a unilateral resistance exercise of the lower limb. Both time- and frequency-domain analyses were performed on the temperature time course of the face and limbs. Particularly, significant correlations between features extracted from the thermal signals and the perceived exertion were found. These findings confirmed the ability of thermal imaging to detect both peripheral and central effects of fatigue in response to physical exercises. These results could foster the employment of infrared thermography to monitor the psychophysiological state of the athletes during training. The possibility to calibrate the training load in accordance with the psychophysiological conditions could improve the performance of the athletes during the training process and competitions.

Abstract

Infrared thermography (IRT) allows to evaluate the psychophysiological state associated with emotions from facial temperature modulations. As fatigue is a brain-derived emotion, it is possible to hypothesize that facial temperature could provide information regarding the fatigue related to exercise. The aim of this study was to investigate the capability of IRT to assess the central and peripheral physiological effect of fatigue by measuring facial skin and muscle temperature modulations in response to a unilateral knee extension exercise until exhaustion. Rate of perceived exertion (RPE) was recorded at the end of the exercise. Both time- (∆T_ROI: pre–post exercise temperature variation) and frequency-domain (∆PSD: pre–post exercise power spectral density variation of specific frequency bands) analyses were performed to extract features from regions of interest (ROIs) positioned on the exercised and nonexercised leg, nose tip, and corrugator. The ANOVA-RM revealed a significant difference between ∆T_ROI (F_(1.41,9.81) = 15.14; p = 0.0018), and between ∆PSD of myogenic (F_(1.34,9.39) = 15.20; p = 0.0021) and neurogenic bands (F_(1.75,12.26) = 9.96; p = 0.0034) of different ROIs. Moreover, significant correlations between thermal features and RPE were found. These findings suggest that IRT could assess both peripheral and central responses to physical exercise. Its applicability in monitoring the psychophysiological responses to exercise should be further explored

Putting the Squeeze on Compression Garments: Current Evidence and Recommendations for Future Research: A Systematic Scoping Review

Background

Compression garments are regularly worn during exercise to improve physical performance, mitigate fatigue responses, and enhance recovery. However, evidence for their efficacy is varied and the methodological approaches and outcome measures used within the scientific literature are diverse.

Objectives

The aim of this scoping review is to provide a comprehensive overview of the effects of compression garments on commonly assessed outcome measures in response to exercise, including: performance, biomechanical, neuromuscular, cardiovascular, cardiorespiratory, muscle damage, thermoregulatory, and perceptual responses.

Methods

A systematic search of electronic databases (PubMed, SPORTDiscus, Web of Science and CINAHL Complete) was performed from the earliest record to 27 December, 2020.

Results

In total, 183 studies were identified for qualitative analysis with the following breakdown: performance and muscle function outcomes: 115 studies (63%), biomechanical and neuromuscular: 59 (32%), blood and saliva markers: 85 (46%), cardiovascular: 76 (42%), cardiorespiratory: 39 (21%), thermoregulatory: 19 (10%) and perceptual: 98 (54%). Approximately 85% (n = 156) of studies were published between 2010 and 2020.

Conclusions

Evidence is equivocal as to whether garments improve physical performance, with little evidence supporting improvements in kinetic or kinematic outcomes. Compression likely reduces muscle oscillatory properties and has a positive effect on sensorimotor systems. Findings suggest potential increases in arterial blood flow; however, it is unlikely that compression garments meaningfully change metabolic responses, blood pressure, heart rate, and cardiorespiratory measures. Compression garments increase localised skin temperature and may reduce perceptions of muscle soreness and pain following exercise; however, rating of perceived exertion during exercise is likely unchanged. It is unlikely that compression garments negatively influence exercise-related outcomes. Future research should assess wearer belief in compression garments, report pressure ranges at multiple sites as well as garment material, and finally examine individual responses and varying compression coverage areas.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40279-021-01604-9.

Short-Term Skin Temperature Responses to Endurance Exercise: A Systematic Review of Methods and Future Challenges in the Use of Infrared Thermography

BACKGROUND

Body temperature is often assessed in the core and the skin. Infrared thermography has been used to measure skin temperature (Tsk) in sport research and clinical practice. This study aimed to explore the information reported to date on the use of infrared thermography to detect short-term Tsk responses to endurance exercise and to identify the methodological considerations and knowledge gaps, and propose future directions.

METHOD

A web search (PubMed, Science Direct, Google Scholar, and Web of Science) was conducted following systematic review guidelines, and 45 out of 2921 studies met the inclusion criteria (endurance sports, since 2000, English, full text available).

RESULTS

A total of 45 publications were extracted, in which most of the sample were runners (n = 457, 57.9%). Several differences between IRT imaging protocols and ROI selection could lead to potential heterogeneity of interpretations. These particularities in the methodology of the studies extracted are widely discussed in this systematic review.

CONCLUSIONS

More analyses should be made considering different sports, exercise stimuli and intensities, especially using follow-up designs. Study-derived data could clarify the underlying thermo physiological processes and assess whether Tsk could be used a reliable proxy to describe live thermal regulation in endurance athletes and reduce their risk of exertional heat illness/stroke. Also more in-depth analyses may elucidate the Tsk interactions with other tissues during exercise-related responses, such as inflammation, damage, or pain.

Effects of 24 h Compression Interventions with Different Garments on Recovery Markers during Running

Compression and temperature manipulation are discussed as strategies to improve performance markers and recovery in sports. Here, we investigate the effects of compression stockings made with fabric, either combined or not with heating and cooling substances, on variables related to running performance and recovery. Ten trained runners (mean ± standard deviation age 45 ± 9 years old, body mass 69 ± 7 kg, height 166 ± 4 cm) with no experience of using compression garments performed an intense running session of 10 km, then wore a stocking for 24 h (randomized; without compression, compression, compression with camphor, and compression with menthol), and were evaluated on the following day, after running 5 km. The different types of compression stockings used 24 h before exercise did not affect running kinematics (p > 0.14), skin temperature (p > 0.05), heart rate (p > 0.12; mean value of maximal heart rate 156 bpm), comfort perception (p = 0.13; mean value of 7/10 points), or perception of recovery (p = 0.13; mean value of 7/10 points). In general, there were no effects of 24 h pre-exercise lower leg compression, including those treated with menthol and camphor applications on running kinematics, skin temperature, heart rate, or recovery perception in athletes undertaking consecutive running exercises.

Thermal Imaging of Exercise-Associated Skin Temperature Changes in Swimmers Subjected to 2-min Intensive Exercise on a VASA Swim Bench Ergometer

An important element of swimming training is the improvement of muscle strength and the technique of swimming movements on dry land. The heat generated by the muscles involved in the effort contributes to a change in the temperature of the skin surface, which can be assessed by the IRT method. The aim of the study was to assess the symmetry and dynamics of changes in surface temperatures of selected areas of the body in swimmers after exercise on a swimming ergometer with the use of IRT. A total of 12 swimmers (aged 19 ± 1.3 years) completed a two-minute stress test (front crawl swimming movements) using a VASA Swim Ergometer, with a load of 5. Using an IRT camera (FLIR E60), postexercise changes in back and upper limbs surface temperature in relation to the resting values were observed. After exercise, the temperature value of all assessed areas decreased, apparently in the area of the back and the back of the arms, returning to the baseline values after 12 min of observation. There was no asymmetry in mean temperature values between the right and left upper limbs. IRT is a noninvasive and sensitive tool for the individual analysis of changes in body surface temperature in swimmers after training on dry land.

Effects of Wearing Compression Stockings on Exercise Performance and Associated Indicators: A Systematic Review

This systematic review investigated the effects of wearing below-knee compression stockings (CS) on exercise performance (or sports activity) and associated physiological and perceived indicators. We searched articles on PubMed using the following terms: "graduated compression stockings"; "compression stockings"; "graduated compression socks"; "compression socks" combined with "performance", "athletes", "exercise", "exercise performance", "fatigue", "sports" and "recovery", resulting in 1067 papers. After checking for inclusion criteria (e.g., original studies, healthy subjects, performance analysis), 21 studies were selected and analyzed. We conclude that wearing CS during exercise improved performance in a small number of studies. However, wearing CS could benefit muscle function indicators and perceived muscle soreness during the recovery period. Future research should investigate the chronic effect of CS on Sports Medicine and athletic performance.

Differences between the most used equations in BAT-human studies to estimate parameters of skin temperature in young lean men

Cold exposure is necessary to activate human brown adipose tissue (BAT), resulting in heat production. Skin temperature is an indirect measure to monitor the body's reaction to cold. The aim of this research was to study whether the most used equations to estimate parameters of skin temperature in BAT-human studies measure the same values of temperature in young lean men (n = 11: 23.4 ± 0.5 years, fat mass: 19.9 ± 1.2%). Skin temperature was measured with 26 ibuttons at 1-minute intervals in warm and cold room conditions. We used 12 equations to estimate parameters of mean, proximal, and distal skin temperature as well as skin temperature gradients. Data were analysed with Temperatus software. Significant differences were found across equations to measure the same parameters of skin temperature in warm and cold room conditions, hampering comparison across studies. Based on these findings, we suggest to use a set of 14 ibuttons at anatomical positions reported by ISO STANDARD 9886:2004 plus five ibuttons placed on the right supraclavicular fossa, right middle clavicular bone, right middle upper forearm, right top of forefinger, and right upper chest.

Dedicated tool to assess the impact of a rhetorical task on human body temperature

INTRODUCTION

Functional infrared thermal imaging is a method widely used in medicine, including analysis of the mechanisms related to the effect of emotions on physiological processes. The article shows how the body temperature may change during stress associated with performing a rhetorical task and proposes new parameters useful for dynamic thermal imaging measurements MATERIALS AND METHODS: 29 healthy male subjects were examined. They were given a rhetorical task that induced stress. Analysis and processing of collected body temperature data in a spatial resolution of 256×512pixels and a temperature resolution of 0.1°C enabled to show the dynamics of temperature changes. This analysis was preceded by dedicated image analysis and processing methods RESULTS: The presented dedicated algorithm for image analysis and processing allows for fully automated, reproducible and quantitative assessment of temperature changes and time constants in a sequence of thermal images of the patient. When performing the rhetorical task, the temperature rose by 0.47±0.19°C in 72.41% of the subjects, including 20.69% in whom the temperature decreased by 0.49±0.14°C after 237±141s. For 20.69% of the subjects only a drop in temperature was registered. For the remaining 6.89% of the cases, no temperature changes were registered CONCLUSIONS: The performance of the rhetorical task by the subjects causes body temperature changes. The ambiguous temperature response to the given stress factor indicates the complex mechanisms responsible for regulating stressful situations. Stress associated with the examination itself induces body temperature changes. These changes should always be taken into account in the analysis of infrared data.

Wearing graduated compression stockings augments cutaneous vasodilation but not sweating during exercise in the heat

The activation of cutaneous vasodilation and sweating are essential to the regulation of core temperature during exercise in the heat. We assessed the effect of graduated compression induced by wearing stockings on cutaneous vasodilation and sweating during exercise in the heat (30°C). On two separate occasions, nine young males exercised for 45 min or until core temperature reached ~1.5°C above baseline resting while wearing either (1) stockings causing graduated compression (graduate compression stockings, GCS), or (2) loose‐fitting stockings without compression (Control). Forearm vascular conductance was evaluated by forearm blood flow (venous occlusion plethysmography) divided by mean arterial pressure to estimate cutaneous vasodilation. Sweat rate was estimated using the ventilated capsule technique. Core and skin temperatures were measured continuously. Exercise duration was similar between conditions (Control: 42.2 ± 3.6 min vs. GCS: 42.2 ± 3.6 min, P = 1.00). Relative to Control, GCS increased forearm vascular conductance during the late stages (≥30 min) of exercise (e.g., at 40 min, 15.6 ± 5.6 vs. 18.0 ± 6.0 units, P = 0.01). This was paralleled by a greater sensitivity (23.1 ± 9.1 vs. 32.1 ± 15.0 units°C⁻¹, P = 0.043) and peak level (14.1 ± 5.1 vs. 16.3 ± 5.7 units, P = 0.048) of cutaneous vasodilation as evaluated from the relationship between forearm vascular conductance with core temperature. However, the core temperature threshold at which an increase in forearm vascular conductance occurred did not differ between conditions (Control: 36.9 ± 0.2 vs. GCS: 37.0 ± 0.3°C, P = 0.13). In contrast, no effect of GCS on sweating was measured (all P > 0.05). We show that the use of GCS during exercise in the heat enhances cutaneous vasodilation and not sweating.

Wearing graduated compression stockings augments cutaneous vasodilation in heat-stressed resting humans

PURPOSE

We investigated whether graduated compression induced by stockings enhances cutaneous vasodilation in passively heated resting humans.

METHODS

Nine habitually active young men were heated at rest using water-perfusable suits, resulting in a 1.0 °C increase in body core temperature. Heating was repeated twice on separate occasions while wearing either (1) stockings that cause graduated compression (pressures of 26.4 ± 5.3, 17.5 ± 4.4, and 6.1 ± 2.0 mmHg at the ankle, calf, and thigh, respectively), or (2) loose-fitting stockings without causing compression (Control). Forearm vascular conductance during heating was evaluated by forearm blood flow (venous occlusion plethysmography) divided by mean arterial pressure to estimate heat-induced cutaneous vasodilation. Body core (esophageal), skin, and mean body temperatures were measured continuously.

RESULTS

Compared to the Control, forearm vascular conductance during heating was higher with graduated compression stockings (e.g., 23.2 ± 5.5 vs. 28.6 ± 5.8 units at 45 min into heating, P = 0.001). In line with this, graduated compression stockings resulted in a greater sensitivity (27.5 ± 8.3 vs. 34.0 ± 9.4 units °C^-1, P = 0.02) and peak level (25.5 ± 5.8 vs. 29.7 ± 5.8 units, P = 0.004) of cutaneous vasodilation as evaluated from the relationship between forearm vascular conductance with mean body temperature. In contrast, the mean body temperature threshold for increases in forearm vascular conductance did not differ between the Control and graduated compression stockings (36.5 ± 0.1 vs. 36.5 ± 0.2 °C, P = 0.85).

CONCLUSIONS

Our results show that graduated compression associated with the use of stockings augments cutaneous vasodilation by modulating sensitivity and peak level of cutaneous vasodilation in relation to mean body temperature. However, the effect of these changes on whole-body heat loss remains unclear.

Validation of the thermophysiological model by Fiala for prediction of local skin temperatures

The most complete and realistic physiological data are derived from direct measurements during human experiments; however, they present some limitations such as ethical concerns, time and cost burden. Thermophysiological models are able to predict human thermal response in a wide range of environmental conditions, but their use is limited due to lack of validation. The aim of this work was to validate the thermophysiological model by Fiala for prediction of local skin temperatures against a dedicated database containing 43 different human experiments representing a wide range of conditions. The validation was conducted based on root-mean-square deviation (rmsd) and bias. The thermophysiological model by Fiala showed a good precision when predicting core and mean skin temperature (rmsd 0.26 and 0.92 °C, respectively) and also local skin temperatures for most body sites (average rmsd for local skin temperatures 1.32 °C). However, an increased deviation of the predictions was observed for the forehead skin temperature (rmsd of 1.63 °C) and for the thigh during exercising exposures (rmsd of 1.41 °C). Possible reasons for the observed deviations are lack of information on measurement circumstances (hair, head coverage interference) or an overestimation of the sweat evaporative cooling capacity for the head and thigh, respectively. This work has highlighted the importance of collecting details about the clothing worn and how and where the sensors were attached to the skin for achieving more precise results in the simulations.

Effect of saddle height on skin temperature measured in different days of cycling

Infrared thermography can be useful to explore the effects of exercise on neuromuscular function. During cycling, it could be used to investigate the effects of saddle height on thermoregulation. The aim of this study was to examine whether different cycling postures, elicited by different knee flexion angles, could influence skin temperature. Furthermore, we also determined whether the reproducibility of thermal measurements in response to cycling differed in the body regions affected or not affected by saddle height. Sixteen cyclists participated in three tests of 45 min of cycling at their individual 50 % peak power output. Each test was performed in a different knee flexion position on the bicycle (20°, 30°, 40° knee flexion when the pedal crank was at 180°). Different knee angles were obtained by changing saddle height. Skin temperatures were determined by infrared thermography before, immediately after and 10 min after the cycling test, in 16 different regions of interest (ROI) in the trunk and lower limbs. Changes in saddle height did not result in changes in skin temperature in the ROI. However, lower knee flexion elicited higher temperature in popliteus after cycling than higher flexion (p = 0.008 and ES = 0.8), and higher knee flexion elicited lower temperature variation in the tibialis anterior than intermediate knee flexion (p = 0.004 and ES = 0.8). Absolute temperatures obtained good and very good intraday reproducibility in the different measurements (ICCs between 0.44 and 0.85), but temperature variations showed lower reproducibility (ICCs between 0.11 and 0.74). Different postures assumed by the cyclist due to different saddle height did not influence temperature measurements. Skin temperature can be measured on different days with good repeatability, but temperature variations can be more sensitive to the effects of an intervention.