The Dynamic and Correlation of Skin Temperature and Cardiorespiratory Fitness in Male Endurance Runners

Exploring the correlation of skin temperature and body composition in athletes undergoing exhaustive physical exercise

During strenuous exercise, skin temperature (Tsk) plays an essential role in thermoregulatory processes. As indicated in the literature, its response might be influenced by body composition, among other factors. Hence, the objectives of this investigation were to determine whether there is a correlation between selected body components, specifically fat tissue and muscle tissue, and Tsk during graded exercise and recovery in athletes, and to identify which body component exhibits the strongest correlation with Tsk. Participants were grouped according to their aerobic capacity (VO2max/kg). A significant main effect was observed for the test stages (p < .001, η2 = 0.71), with Tsk decreasing from the start of the exercise, significantly decreasing at 12 km/h-1 (p < .001), and then increasing after exercise, especially within the first 5 min of recovery. Weak and non-significant effect for group/stage interaction was detected (p = .374, η2 = 0.03). A significant negative correlation was found between Tsk and both total tissue fat [%] (-0.51 < r < -0.63, p < .001) and lower limb tissue fat [%] (-0.50 < r < -0.71, p < .001) across all test stages. The correlation between Tsk and BMI was inconsistent, appearing only during the first stage of exercise and throughout recovery. No correlation was observed between Tsk and skeletal muscle mass, appendicular lean soft tissue, or relative skeletal muscle index. Endurance running to exhaustion leads to a progressive decrease in the Tsk of the lower extremity, followed by rewarming during recovery. The observed inverse correlation between adipose tissue and Tsk, along with the distinct temperature trends in groups with varying levels of fat tissue, could imply that the skin and subcutaneous tissue complex may play a more intricate role in thermal energy exchange beyond its insulating function. This implies a multifaceted involvement of these tissues in thermoregulation.

Exercise-induced changes in lower limbs skin temperature against plasma ATP among individuals with various type and level of physical activity

The objective of the study was to examine the lower limbs skin temperature (TSK) changes in response to exhaustive whole-body exercise in trained individuals in reference to changes in plasma adenosine triphosphate (ATP). Eighteen trained participants from distinct sport type ‒ endurance (25.2 ± 4.9 yr) and speed-power (25.8 ± 3.1 yr), and 9 controls (24,9 ± 4,3 yr) ‒ were examined. Lower limbs TSK and plasma ATP measures were applied in parallel in response to incremental treadmill test and during 30-min recovery period. Plasma ATP kinetics were inversely associated to changes in TSK. The first significant decrease in TSK (76-89% of V˙ O2MAX) occurred shortly before a significant plasma ATP increase (86-97% of V˙ O2MAX). During recovery, TSK increased, reaching pre-exercise values (before exercise vs. after 30-min recovery: 31.6 ± 0.4 °C vs. 32.0 ± 0.8 °C, p = 0.855 in endurance; 32.4 ± 0.5 °C vs. 32.9 ± 0.5 °C, p = 0.061 in speed-power; 31.9 ± 0.7 °C vs. 32.4 ± 0.8 °C, p = 0.222 in controls). Plasma ATP concentration did not returned to pre-exercise values in well trained participants (before exercise vs. after 30-min recovery: 699 ± 57 nmol l-1 vs. 854 ± 31 nmol l-1, p < 0.001, η2 = 0.961 and 812 ± 35 nmol l-1 vs. 975 ± 55 nmol l-1, p < 0.001, η2 = 0.974 in endurance and speed-power, respectively), unlike in controls (651 ± 40 nmol l-1 vs. 687 ± 61 nmol·l-1, p = 0.58, η2 = 0.918). The magnitude of TSK and plasma ATP response differed between the groups (p < 0.001, η2 = 0.410 for TSK; p < 0.001, η2 = 0.833 for plasma ATP). We conclude that lower limbs TSK change indirectly corresponds to the reverse course of plasma ATP during incremental exercise and the magnitude of the response depends on the level of physical activity and the associated to it long-term metabolic adaptation.

Health benefits of short Taichi Qigong exercise (STQE) to University Students' core strength, lower limb explosive force, cardiopulmonary endurance, and anxiety: A Quasi experiment research

BACKGROUND

College students' physical fitness has declined over the past decades. Taichi Qigong exercise offers numerous health benefits and could serve as a suitable option for them. Traditional programs, however, are time-consuming and necessitate long-term commitments. Therefore, a more cost-effective intervention is needed.

METHODS

The study enrolled a total of 31 students who actively participated in a 5-week STQE program, consisting of three 60-minute sessions per week. Physical and mental health assessments included the Plank test, vital capacity measurement, 1000/800 m run test, standing jump, and the Zung Self-Rating Scale. Data analysis was performed using SPSS.

RESULTS

Following the STQE intervention, participants showed improvement in core strength (28.1 seconds in the Plank test, P = .025) and lower limb explosive force (6.52 cm in the standing jump test, P = .011), accompanied by a decrease in anxiety levels (a reduction of 3.41 in the Zung Self-Rating Scale, P = .039). However, no significant improvements were observed in cardiopulmonary endurance, as evidenced by a non-significant increase of 237.84 mL in vital capacity (P = .134) and a non-significant reduction of 1.6 seconds in the 1000/800 m run test (P = .764).

CONCLUSION

The study suggests that the STQE program effectively improves core strength, lower limb explosive force, and reduces anxiety levels among university students.

Response of skin temperature, blood ammonia and lactate during incremental exercise until exhaustion in elite athletes

The study aimed to evaluate the lower limb skin temperature (Tsk) and blood concentrations of lactate (LA) and ammonia (NH3) during exercise and recovery. Eleven elite sprint athletes (25 ± 3.4 yrs) and 11 elite endurance athletes (24.45 ± 5.4 yrs) performed an incremental running test until exhaustion. Body composition was estimated using the DXA method. Thermograms of the anterior and posterior surfaces of the lower limbs were recorded at rest, before each test stage (every 3 min, starting from 10 km h-1 and increasing by 2 km h-1), and in the 5th, 10th, 15th, 20th, and 30th minute of recovery. Endurance athletes had a higher maximum oxygen uptake than sprint athletes (5.0 ± 0.7 vs 4.3 ± 0.4 l·kg-1, p = 0.018), lower percentage of lean content (79 ± 2 vs 83 ± 2%, p < 0.001), and a higher percentage of fat content in the lower limbs (17 ± 2 vs 12 ± 2%, p < 0.001). In both groups, a significant decrease in Tsk was observed compared to resting value (endurance athletes-31.5 ± 0.6 °C; sprint athletes-32.3 ± 0.6 °C), during exercise (p < 0.001) and rewarming during recovery (p < 0.001). However, endurance athletes had a lower Tsk than sprint athletes at the exhaustion point (30.0 ± 1.1 vs 31.6 ± 0.8 °C, p < 0.05) and the pattern of change in Tsk differed between groups (p < 0.001). Tsk in the endurance athletes group decreased throughout the exercise protocol and returned more rapidly to initial values during recovery, while Tsk in the sprint group stabilised between moderate intensity and exhaustion, recovering more slowly after exercise. Both LA (endurance athletes-max 10.2 ± 1.5; sprint athletes-max 10.1 ± 1.4 mmol⋅L-1, p < 0.001) and NH3 (endurance athletes-max 75.6 ± 11.5; sprint athletes-max 76.7 ± 9.0 mmol⋅L-1, p < 0.001) increased during exercise and decreased during recovery (p < 0.001). During exercise, lower levels and slower increases in LA were observed during exercise in the endurance athletes' group (p < 0.05). A negative correlation was revealed between Tsk and fat percentage (r = -0.43 to -0.71, p < 0.05). Tsk was positively correlated with LA during recovery (r = 0.43 to 0.48, p < 0.05), and negatively during recovery (r = -0.45 to -0.54, p < 0.05). Differences between groups in maximum aerobic capacity, the pattern of change in Tsk, and the correlation between Tsk and LA suggest that individuals who decrease less Tsk during exercise and higher Tsk during recovery are those with better aerobic capacity. In addition, athletes with less body fat dissipate heat from their tissues more efficiently.

Assessing aerobic physical efficiency through temple surface temperature measurements during light, heavy exercise, and recovery

The study was conducted to determine thecorrelation between the selected measures of aerobic physical efficiency and changes in the temple surface temperature in response to light and heavy exercise. 25 physically active men aged 19-25 were recruited for the study. They performed a graded exercise test on a cycle ergometer to measure maximum power (Pmax) and a test verifying the value of maximum oxygen uptake (VO2max). Then, two 3-min submaximal efforts with constant-intensity of 2.2 W·kgLBM-1 and 5 W·kgLBM-1, respectively were performed. During the constant-intensity efforts, the temperature of the temple surface was measured. Then, the difference between the temperature of the temple measured at the end of the exercise and the temperature measured at the beginning of the exercise was calculated (ΔT1-2.2, ΔT1-5, respectively). It was shown that ΔT1-2.2 correlated statistically significantly with VO2max (ml·min-1·kg-1) (r = 0.49; p = 0.01) and Pmax (W·kg-1) (r = 0.41, p = 0.04). Moreover, ΔT1-5 correlated statistically significantly with VO2max (l·min-1) (r = - 0.41; p = 0.04). Changes in body surface temperature in response to light exercise positively correlate with measurements of aerobic physical efficiency, such as VO2max and Pmax. When the exercise intensity is high (5 W·kgLBM-1), the correlation between exercise body temperature changes and VO2max becomes negative.

The use of thermal imaging for monitoring the training progress of professional male sweep rowers

This study assesses the thermal profile of the skin in highly trained rowers and investigates the relationship between resting skin temperature (Ts) and the muscle peak torque (PT) measured in statics at the beginning (autumn) and the end (spring) of the preparatory period. Ten professional male sweep rowers, members of the Polish national rowing team, were investigated. A thermal imaging camera was used to analyze the Ts. The PT of the muscles involved in the rowing cycle were measured isometrically. No significant temperature asymmetries were found, except in front of arms after exercise in the spring (p = 0.0228). In contrast, the PT test in the autumn confirmed the significant asymmetry of the knee joint extensors (p = 0.0192). In spring compared to autumn, Ts in many areas of the body were slightly higher, as was PT of underlying muscles. Significant correlations between resting Ts and PT of the underlying muscles were found. Thermal imaging makes it possible to observe changes in skin temperature and symmetry before and after exercise. At this stage, it does not appear to be a method that, without supporting of other methods such as those assessing muscle function, will allow monitoring of training progress.

The Heat Shock Connection: Skeletal Muscle Hypertrophy and Atrophy

Skeletal muscle is an integral tissue system that plays a crucial role in the physical function of all vertebrates and is a key target for maintaining or improving health and performance across the lifespan. Based largely on cellular and animal models, there is some evidence that various forms of heat stress with or without resistance exercise may enhance skeletal muscle growth or reduce its loss. It is not clear whether these stimuli are similarly effective in humans or meaningful in comparison to exercise alone across various heating methodologies. Furthermore, the magnitude by which heat stress may influence whole body thermoregulatory responses and the connection to skeletal muscle adaptation remains ambiguous. Finally, the underlying mechanisms, which may include interaction between relevant heat shock proteins and intracellular hypertrophy and atrophy related factors, remain unclear. In this narrative mini-review we examine the relevant literature regarding heat stress alone or in combination with resistance exercise emphasizing skeletal muscle hypertrophy and atrophy across cellular and animal models, as well as human investigations. Additionally, we present working mechanistic theories for heat shock protein mediated signaling effects regarding hypertrophy and atrophy related signaling processes. Importantly, continued research is necessary to determine the practical effects and mechanisms of heat stress with and without resistance exercise on skeletal muscle function via growth and maintenance.

Practical research on orienteering physical education in universities in northeast China

BACKGROUND AND OBJECTIVE:

Orienteering, which is one of the popular physical educations in the world, is an emerging sport integrating knowledge, competition, fun, and collaborative attributes. Although it started late in China, it has developed rapidly in recent years in most places except the northeast and northwest parts of the country.

METHODS:

In order to accelerate the development of orienteering in the northeast, given the climate and social characteristics of this area, we built a four-in-one orienteering development model including a theory course, a social component, a team, and events based on the longtime practice of Harbin Engineering University.

RESULTS:

The research results have practical reference significance for orienteering at universities in China, as well as at universities and commercial clubs in other areas of the world.

Consequences of police-related personal protective equipment and physical training status on thermoregulation and exercise energy expenditure

BACKGROUND

The aim was to examine the impact of personal protective equipment (PPE) on human thermoregulation and its alteration in groups of different training status.

METHODS

45 men performed a maximum voluntary contraction test in an upright pull position to determine lower body strength and a graded treadmill test to determine maximum oxygen uptake (VO2max). Body composition was estimated via bioelectric impedance analysis. According to specific cutoff values, participants were assigned to a group of endurance-trained, strength-trained, endurance- and strength-trained, or untrained individuals. Subsequently, they completed two graded exercise tests until volitional exhaustion, once wearing sports wear (SPW) and once wearing PPE (20.9 kg). Participants were weighed before and afterward to investigate sweat loss and sweat rate. Body temperature was measured continuously from the tympanic membrane. Energy expenditure was derived from breathing gas analysis.

RESULTS

Sweat rate was 91% higher in PPE than in SPW but not significantly differnt between groups (p > 0.05). Body temperature was significantly higher in PPE during submaximal (+1.14 ± 0.45 °C) and maximal exercise intensity (+0.68 ± 0.57 °C) and was poorely related to VO2max and body composition. Energy expenditure significantly differed between both garments (+37% in PPE) and groups (p < 0.05). Additionally, energy expenditure significantly correlated with body weight (r = 0.84 in SPW and r = 0.68 in PPE).

CONCLUSIONS

Strength training alone does not seem to have any or negligible effects on thermoregulation. Endurance training and weight management might lead to rather small improvements in heat tolerance.