28: Post-exercise systemic heat therapy decreases the inflammation process during recovery: a systematic review and meta-analysis

Freitag, Livia1; Herten, Miriam1; Bianchi, Giannina1; Clijsen, Ron1,2,3,4; Hohenauer, Erich1,2,4,5

  1. University of Applied Sciences and Arts of Southern Switzerland, Rehabilitation and Exercise Science Laboratory (RES lab), Landquart, Switzerland
  2. International University of Applied Sciences THIM, Landquart, Switzerland
  3. Bern University of Applied Sciences, Department of Health, Berne, Switzerland
  4. Vrije Universiteit Brussel, Department of Movement and Sport Sciences, Brussels, Belgium
  5. University of Fribourg, Department of Neurosciences and Movement Science, Fribourg, Switzerland


Systemic heat therapies are often used in the general population for pleasure and relaxation [1]. Forms such as hot water immersion, sauna bathing, steam bathing, and infrared bathing are defined as systemic heat therapies [2]. The effects of these treatments can vary widely including a decrease in mean arterial pressure, systolic pressure, diastolic pressure [3] and an increase in glucose metabolism [4] and insulin sensitivity [5]. Also, an increase in muscle and tendon flexibility [6] and a reduction of subacute and chronic musculoskeletal pain were observed [7]. In sports, systemic heat therapies are regularly used after activities and are recommended as a recovery method [8]. Recovery is linked to a lower injury rate and increased competition performance. To the best of our knowledge, no evidence-based recommendations exist about post-exercise systemic heat therapies. Therefore, our aim was i) to generate an overview of the currently available literature and ii) to establish the results of post-exercise systemic heat therapies.


The following review and meta-analysis were performed according to the current guidelines “Preferred Reporting Items for Systematic Reviews and Meta-Analyses“ (PRISMA) [9]. A systematic literature search was conducted using the four medicinal online databases Pubmed, Ovid, EBSCO, and Cochrane. The following criteria were considered: (1) the participants had to be healthy; (2) the study contained an intervention and control group; (3) the intervention group performed a systemic heat therapy after exercise; (4) the heat intervention was a systemic external application above 36°C; (5) the control group underwent passive rest, sham-heat therapy, or a placebo intervention without heat; (6) the results were reported before and after the intervention; and (7) the article was written in English, Dutch, or German. Two researchers identified independently relevant articles. The methodological quality of the included studies was assessed with the help of the reliable and applicable rating tool Cochrane risk of bias tool 2 (RoB 2). The results were extracted and pooled depending on the outcome and measuring time. If significant results were found, the intensity level of the pre-performed exercise, the heating modality, and the temperature were analysed.


A total of n=17 studies met the inclusion criteria. The results of the meta-analysis revealed that participants of the intervention group had significantly lower inflammation blood levels (p = 0.008) within one hour after application compared to the control group. There is evidence, that systemic heat therapies after exercises with higher intensities benefit more than after medium or low-intensity exercises. Studies using hot water immersion and interventions with higher temperatures showed better effects on inflammation blood levels than those using air-heating or lower temperatures. After 72 hours, endurance performance was significantly higher in the intervention group compared to the control group (p = 0.008). Again, a higher benefit was achieved in studies with exercises of higher intensities compared to medium or low intensive exercises. In contrast to these results, the subjective estimation of the muscle soreness showed significantly better results in the control group (p = 0.004) within one hour after the control intervention compared to the heating group. No significant results were found between the groups for the muscle force, jump performance, maximum oxygen capacity, and blood lactate levels at any time point.


Post-exercise systemic heat therapy can lead to significantly lower blood inflammation markers compared to passive recovery within the first hour after application in a healthy population. The best effects were achieved when higher temperatures and the heating modality water were involved. These findings indicate a short-term anti-inflammatory effect of post-exercise systemic heat applications and give the needed evidence-based recommendations for trainers, therapists, athletes, and the general active population. It remains unclear if studies assessing the effectiveness of post-exercise heat therapy in patients will correspond to the present results. A special interest might be in patients with inflammatory diseases.


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5.         Hesketh K, Shepherd SO, Strauss JA, Low DA, Cooper RJ, Wagenmakers AJM, et al. Passive heat therapy in sedentary humans increases skeletal muscle capillarization and eNOS content but not mitochondrial density or GLUT4 content. American Journal of Physiology-Heart and Circulatory Physiology. 2019;317(1):H114-H23.

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