Acute Exercise-Associated Skin Surface Temperature Changes after Resistance Training with Different Exercise Intensities

Abstract

Background: Studies showed, that changes in muscular metabolic-associated heat production and blood circulation during and after muscular work affect skin temperature (T) but the results are inconsistent and the effect of exercise intensity is unclear. Objective: This study investigated the intensity-dependent reaction of T on resistance training. Methods: Ten male students participated. After acclimatization (15 min), the participants completed 3x10 repetitions of unilateral biceps curl with 30, 50 or 70% of their one-repetition-maximum (1RM) in a randomized order. Skin temperature of the loaded and unloaded biceps was measured at rest (Trest), immediately following set 1, 2 and 3 (TS1,TS2,TS3) and 30 minutes post exercise (T1 - T30) with an infrared camera. Results: Two-way ANOVA detected a significant effect of the measuring time point on T (Trest to T30) of the loaded arm for 30% (Eta²=0.85), 50% (Eta²=0.88) and 70% 1RM (Eta²=0.85) and of the unloaded arm only for 30% 1RM (Eta²=0.41) (p<0.05) but time effects were independent of the exercise intensity (p>0.05). The T values at the different measuring time points (Trest - T30) did not differ between the intensities at any time point. The loaded arm showed a mean maximum T rise to Trest of 1.8°C and on average, maximum T was reached approximately 5 minutes after the third set. Conclusion: This study indicate a rise of T, which could be independent of the exercise intensity. Infrared thermography seems to be applicable to identify the primary used functional muscles in resistance training but this method seems not suitable to differentiate between exercise intensity from 30 to 70% 1RM.

Superficial thermal response to CrossFit® workout

“…So, this combination of exercises seems to have been responsible for the increase in temperature found in the aforementioned ROI. Our data is aligned with that in previous studies [37][38][39][40] , however, it is in disagreement with others 41,42 .…”

Effects of Resistance Training on Skin Temperature and Its Relationship with Central Nervous System (CNS) Activation

“…A sample size calculation was initially performed with G*Power software (Heinrich-Heine-Universität, Düsseldorf, Germany). The effect size of exercise on skin temperature changes reported in the literature is large [ 23 , 24 ], considering an effect size of 0.4, a statistical power of 0.80, and three repeated measurements for the repeated measures ANOVA assessing the effects of resistance training on skin temperature, a minimum sample size of 12 was calculated. To account for any dropouts and other unforeseen shortcomings, 20 healthy and trained male volunteers aged 25.39 ± 8.21 years (height: 178.88 ± 8.37 cm; weight: 82.38 ± 6.80 kg; BMI: 25.76 ± 1.45) were recruited.…”

“…Considering that the acute effects of the exercise on skin thermal response are different even after a short recovery time [ 23 ], a last set of thermograms, RPE scores (5.26 ± 1.81) and Omegawave ® were taken 20 min after completion of strength training. During this resting time, the subject remained seated on their gluteus, avoiding any contact of the posterior thigh with the chair to prevent any interference with the Tsk assessment.…”

Infrared Thermography in Wound Care, Surgery, and Sports Medicine: A Review

“…This thermographic pattern reflects the redistribution of the blood flow to muscles during exercise and back to the skin after it to promote heat dissipation (Zaïdi et al, 2007;Balci et al, 2016;Drzazga et al, 2018;Hillen et al, 2020). In contrast, resistance exercise produces an increased skin temperature pattern related to the stressed muscles which is more pronounced in trained athletes, compared to untrained individuals, and in younger people compared to older individuals (Weigert et al, 2018;dos Santos Bunn et al, 2020). These findings can be linked to local and systemic adaptations of myocutaneous blood flow and reflect the muscles' metabolism while under stress, as they have also been seen in individuals experiencing ergonomic injuries (Alexandre et al, 2017).…”