Correlation between skin temperature in the lower limbs and biochemical marker, performance data, and clinical recovery scales

Response of infrared thermography related parameters to (non-)sport specific exercise and relationship with internal load parameters in individual and team sport athletes-a systematic review

Introduction

Monitoring internal load is crucial for athletes but often requires invasive methods for muscle-related parameters, limiting practicality. Infrared thermography (IRT) related parameters might overcome this limitation. This systematic review aimed to examine the available literature on the response of IRT related parameters to (non-)sport specific exercise and reveal relationships with internal load parameters in athletic populations.

Methods

Four scientific databases were systematically searched (February 2024) with keywords related to IRT, load, and sports disciplines. Risk of bias was evaluated using QUADAS-2. Main inclusion criteria for studies were i) reporting of IRT related parameters and other internal load parameters prior/post (non-)sport specific exercise ii) inclusion of least Tier 2 athletes ≥ 18 years. After identifying n = 10,538 studies, 13 articles (n = 231 participants) were included.

Results

Following (non-)sport specific exercise in athletic populations, the majority of relevant studies showed a decrease in IRT related parameters within 15 min, while studies showed an increase in IRT related parameters following 30 min, 24 h, 48 h, and 72 h after exercise cessation. Relationships between alterations in IRT related parameters and other internal load parameters are inconsistent across the literature.

Conclusion

While the majority of studies show an increase in IRT related parameters following (non-)sport specific exercise, relationships with other internal load parameters and underlying physiological mechanisms evoking IRT related alterations are not conclusively revealed in athletic populations. Future research needs to assess the relationship of IRT related parameters especially with inflammatory parameters in athletic populations following (non-)sport specific exercise. Practitioners might assess IRT related parameters in conjunction with other load parameters.

Effect of different Volumes of exercise on skin temperature responses over the following 24 hours

Skin temperature responses have been advocated to indicate exercise-induced muscle soreness and recovery status. While the evidence is contradictory, we hypothesize that the presence of muscle damage and the time window of measurement are confounding factors in the skin temperature response. The objective was to determine whether skin temperature is influenced by different workloads and the time course of temperature measurements over the following 24 h. 24 trained male military were assigned to one of three groups: GC group (n = 8) serving as control not performing exercises, GE group (n = 8) performing a simulated military combat protocol in an exercise track with different obstacles but designed not to elicit muscle damage, and the GEMD group (n = 8) performing the simulated military combat protocol plus 5 sets of 20 drop jumps, with 10-sec between repetitions and with 2-min of rest between sets aiming to induce muscle damage. Skin temperature was measured using infrared thermography before exercise (Pre) and 4 (Post4h), 8 (Post8h) and 24h (Post24h) post-exercise. Perception of pain (DOMS) was evaluated Pre, Post24h, and Post48h, and countermovement jump height was evaluated at Pre and Post24h. DOMS did not differ between groups in the Pre and Post24h measures but GEMD presented higher DOMS than the other groups at Post48h (p < 0.001 and large effect size). Jump height did not differ for GEMD and GC, and GE presented higher jump height at Post24h than GC (p = 0.02 and large effect size). Skin temperature responses of GEMD and GG were similar in all measurement moments (p > 0.22), and GE presented higher skin temperature than the GC and the GEMD groups at Post24h (p < 0.01 and large effect sizes). In conclusion, although physical exercise elicits higher skin temperature that lasts up to 24 h following the efforts, muscle soreness depresses this response.

Thermal profile classification of the back of sportive and sedentary healthy individuals

BACKGROUND

Infrared thermography (IRT) is a non-harmful, risk-free imaging technique and it has application for healthy and pathological population.

OBJECTIVE

The aim of this study is to evaluate the thermographic profiles of the back of sport practitioners from different disciplines and compare it with those of sedentary healthy individuals.

METHOD

The back of 160 healthy subjects were evaluated, and participants were grouped considering their sport practice: team sport (TS), individual sport (IS), weight training (WT), inactive (I). Three regions of interest were identified to analyze the cervical, thoracic and lumbar temperatures of the back.

RESULTS

The Multivariate analysis of variance (MANOVA) resulted significant showing statistical differences for the cervical (p < 0.001), dorsal (p = 0.0011), and lumbar areas (p = 0.0366). The Tukey post-hoc test for pairwise comparison showed statistically significant differences between groups. For the cervical area significance was found between the IN and WT group (p = 0.002), the IN and IS group (p < 0.001), IN and TS group (p = 0.020). The dorsal area resulted significant between the IN and WT group (p = 0.007), the IN and IS group (p < 0.001), IN and TS group. The lumbar area showed significant differences only between the IN and WT group and the IN and IS group (p = 0.043).

CONCLUSION

This study demonstrated that inactive individuals manifest a statistically significant higher temperature in the cervical, dorsal and lumbar area of the back compared to sportive individuals.

Thermal resting pattern and acute skin temperature response to exercise in older adults: Role of cardiorespiratory fitness

BACKGROUND

Infrared thermography is a growing area of interest in sports science due to the potential of skin temperature (Tsk) measurements to provide valuable information from rest to exercise. However, limited research exists on Tsk in older adults and the impact of factors such as sex and cardiorespiratory fitness (CRF) on Tsk. This study aims to investigate Tsk at rest and after acute exercise in older adults and assess whether sex or CRF influences Tsk.

METHODS

Ninety-two participants (41 women, 68.48 ± 3.01 years) were examined with a thermographic camera in a conditioned room (23.02 ± 3.01 °C) at rest and after a graded protocol. The Tsk of 25 regions of interest (ROIs) were extracted and analysed.

RESULTS

Men had higher overall Tsk at rest in 76% of ROIs, showing significant differences (p < 0.010) in six specific ROIs, independent of CRF. Both sexes had similar Tsk responses after graded exercise, with increases in distal parts (1.06 ± 0.50 °C), decreases in proximal parts (-0.62 ± 0.42 °C), and stable central Tsk (0.23 ± 0.59 °C). Increases in lower limb Tsk were significantly associated with CRF in men and women (β = 0.438, p = 0.001, and β = 0.535, p < 0.001, respectively), explaining 17% and 27% of the variance, respectively.

CONCLUSIONS

This study demonstrates a sex-specific effect on resting Tsk in older adults, suggesting that sex-specific Tsk patterns should be considered when analysing Tsk in this population. Additionally, the association between increases in lower limb Tsk and CRF suggests that Tsk could be a promising predictor of CRF in older adults.

Acute Recovery after a Fatigue Protocol Using a Recovery Sports Legging: An Experimental Study

Enhancing recovery is a fundamental component of high-performance sports training since it enables practitioners to potentiate physical performance and minimise the risk of injuries. Using a new sports legging embedded with an intelligent system for electrostimulation, localised heating and compression (completely embodied into the textile structures), we aimed to analyse acute recovery following a fatigue protocol. Surface electromyography- and torque-related variables were recorded on eight recreational athletes. A fatigue protocol conducted in an isokinetic dynamometer allowed us to examine isometric torque and consequent post-exercise acute recovery after using the sports legging. Regarding peak torque, no differences were found between post-fatigue and post-recovery assessments in any variable; however, pre-fatigue registered a 16% greater peak torque when compared with post-fatigue for localised heating and compression recovery methods. Our data are supported by recent meta-analyses indicating that individual recovery methods, such as localised heating, electrostimulation and compression, are not effective to recover from a fatiguing exercise. In fact, none of the recovery methods available through the sports legging tested was effective in acutely recovering the torque values produced isometrically.

Association between physical demands, skin temperature and wellbeing status in elite football players

The demanding nature of elite football requires players to be closely monitored to ensure optimal performance and minimize injury risk. This study aimed to evaluate the relationship between physical demands, skin temperature, and well-being status in 30 elite football players over a 12-week competitive period. Thermography assessments, weekly Well-being questionnaires, and daily training and match load recordings were used to gather data. Results indicated that along the microcycles there was a decrease in high-intensity accelerations and decelerations distance completed, while maintaining other high-intensity actions. Furthermore, it was found that high-intensity movements contribute to the generation of thermal asymmetries in the thighs; the adductor thermal asymmetry showed a positive relationship with stress and muscle soreness, the knee thermal asymmetry had a positive relationship with fatigue and a negative relationship with rest and quality of rest, and finally the hamstrings muscles exhibited significant differences between the thermal asymmetry groups, with the high asymmetry completing less high intensity actions than the low asymmetry group. In conclusion, this study highlights the interconnections between physical demands, skin temperature, and well-being in elite football players and provides valuable insights for coaches and trainers in their efforts to optimize performance and health.

Can infrared thermography serve as an alternative to assess cumulative fatigue in women?

Muscle fatigue can limit performance both in sports and daily life activities. Consecutive days of exercise without a proper recovery time may elicit cumulative fatigue. Although it has been speculated that skin temperature could serve as an indirect indicator of exercise-induced adaptations, it is unclear if skin temperature measured by infrared thermography (IRT) could be an outcome related to the effects of cumulative fatigue. In this study, we recruited 21 untrained women and induced cumulative fatigue in biceps brachii over two consecutive days of exercise. We measured delayed onset muscle soreness (DOMS, using a numeric rate scale), maximal strength (using a dynamometer), and skin temperature (using IRT) in exercise and non-exercise muscles. Cumulative fatigue reduced muscle strength and increased DOMS. Skin temperature in the arm submitted to cumulative fatigue was higher for minimum and mean temperature, being asymmetrical in relation to the control arm. We also observed that the variations in the minimum and mean temperatures correlated with the strength losses. In summary, skin temperature measured by IRT seems promising to help detect cumulative fatigue in untrained women, being useful to explain strength losses. Future studies should provide additional evidence for the potential applications not only in trained participants but also in patients that may not be able to report outcomes of scales or precisely report DOMS.

Evaluation of Ibuprofen Use on the Immune System Indicators and Force in Disabled Paralympic Powerlifters of Different Sport Levels

Background: Paralympic powerlifting (PP) training is typically intense and causes fatigue and alterations in the immune system. Objective: To analyze whether IBU would affect performance and the immune system after training in PP. Methodology: 10 athletes at the national level (NL) and 10 at the regional level (RL) participated in the study, where force and blood indicators were evaluated after training. The study took place over three weeks: (1) familiarization and (2 and 3) comparison between recovery methods, with ibuprofen or placebo (IBU vs. PLA), 800 mg. In the evaluation of the force, the peak torque (PT), fatigue index (FI), and blood immune system biomarkers were analyzed. The training consisted of five sets of five repetitions with 80% of one maximum repetition (5 × 5, 80% 1RM) on the bench press. Results: The PT at the national level using IBU was higher than with PLA (p = 0.007, η2p = 0.347), and the FI in the NL was lower with IBU than with PLA (p = 0.002, η2p = 0.635), and when comparing the use of IBU, the NL showed less fatigue than the regional level (p = 0.004, η2p = 0.414). Leukocytes, with the use of IBU in the NL group, were greater than in the RL (p = 0.001, η2p = 0.329). Neutrophils, in the NL with IBU, were greater than in the RL with IBU and PLA (p = 0.025, η2p = 0.444). Lymphocytes, in NL with IBU were lower than in RL with IBU and PLA (p = 0.001, η2p = 0.491). Monocytes, in the NL with IBU and PLA, were lower than in the RL with IBU (p = 0.049, η2p = 0.344). For hemoglobin, hematocrit, and erythrocyte, the NL with IBU and PLA were higher than the RL with IBU and PLA (p < 0.05). Ammonia, with the use of IBU in the NL, obtained values higher than in the RL (p = 0.007), and with the use of PLA, the NL was higher than the RL (p = 0.038, η2p = 0.570). Conclusion: The training level tends to influence the immune system and, combined with the use of the IBU, it tends to improve recovery and the immune system.