Whole-Body Cryotherapy: Potential to Enhance Athlete Preparation for Competition?

Cryogenic Media in Biomedical Applications: Current Advances, Challenges, and Future Perspectives

This paper explores the crucial role of cryogenic mediums in driving breakthroughs within the biomedical sector. The objective was to investigate, critically discuss, and present the current knowledge and state-of-the-art practices, along with the challenges and perspectives of the most common applications. Through an extensive literature review, this work aims to supplement existing research, offering a comprehensive and up-to-date understanding of the subject. Biomedical research involving cryogenic mediums is advancing on multiple fronts, including the development of advanced medical technologies, clinical treatments for life-threatening conditions, high-quality biospecimen preservation, and antimicrobial interventions in industrial food processing. These advances open new horizons and present cutting-edge opportunities for research and the medical community. While the current body of evidence showcases the impressive impact of cryogenic mediums, such as nitrogen, helium, argon, and oxygen, on revolutionary developments, reaching definitive conclusions on their efficiency and safety remains challenging due to process complexity and research scarcity with a moderate certainty of evidence. Knowledge gaps further underline the need for additional studies to facilitate cryogenic research in developing innovative technological processes in biomedicine. These advancements have the potential to reshape the modern world and significantly enhance the quality of life for people worldwide.

A single session of whole-body cryotherapy boosts maximal cycling performance and enhances vagal drive at rest

Whole-body cryotherapy (WBC) has been reported to maximize physical recovery after exercise and reduce the ensuing muscle damage. In addition, WBC triggers cardiovascular responses leading to an increased vagal drive. Here we tested whether WBC may boost exercise performance as well as post-exercise recovery. Moreover, we compared the effects of WBC and exercise on sympathovagal balance and tested whether these two factors may interact. ECG was recorded in 28 healthy adults who underwent rest, all-out effort on a cycloergometer, 5 min recovery and again rest. After 3-5 days, WBC (3 min exposure to - 150 °C air) was applied and the whole procedure repeated. Total exercise duration was split into the time needed to reach peak power output (t_PEAK) and the time to exhaustion (t_EXH). The post-exercise exponential decay of HR was characterized by its delay from exercise cessation (t_DELAY) and by its time constant (τ_OFF). Sympathovagal balance was evaluated by measuring HR variability power in the low (LF) and high (HF) frequency bands, both before exercise and after recovery from it. Sympathetic vs. vagal predominance was assessed by the sympathovagal index LFnu. Paired t-tests indicated that WBC increased t_EXH and reduced t_DELAY, speeding up the HR recovery. These results suggest that WBC may be exploited to boost exercise performance by about 12-14%. ANOVA on HR variability confirmed that exercise shifted the sympathovagal balance towards sympathetic predominance, but it also highlighted that WBC enhanced vagal drive at rest, both before exercise and after full recovery, covering ~ 70% of the exercise effect.

Different Cryotherapy Modalities Demonstrate Similar Effects on Muscle Performance, Soreness, and Damage in Healthy Individuals and Athletes: A Systematic Review with Metanalysis

Background: There are extensive studies focusing on non-invasive modalities to recover physiological systems after exercise-induced muscle damage (EIMD). Whole-body cryotherapy (WBC) and Partial-body cryotherapy (PBC) have been recommended for recovery after EIMD. However, to date, no systematic reviews have been performed to compare their effects on muscle performance and muscle recovery markers. Methods: This systematic review with metanalysis compared the effects of WBC and PBC on muscle performance, muscle soreness (DOMS), and markers of muscular damage following EIMD. We used Pubmed, Embase, PEDro, and Cochrane Central Register of Controlled Trials as data sources. Two independent reviewers verified the methodological quality of the studies. The studies were selected if they used WBC and PBC modalities as treatment and included muscle performance and muscle soreness (DOMS) as the primary outcomes. Secondary outcomes were creatine kinase and heart rate variability. Results: Six studies with a pooled sample of 120 patients were included. The methodological quality of the studies was moderate, with an average of 4.3 on a 0–10 scale (PEDro). Results: Both cryotherapy modalities induce similar effects without difference between them. Conclusion: WBC and PBC modalities have similar global responses on muscle performance, soreness, and markers of muscle damage.

Cardiovascular Effects of Whole-Body Cryotherapy in Non-professional Athletes

Objectives:

The study aimed to investigate changes in heart rate, blood pressure, respiratory rate, oxygen saturation, and body temperature in non-professional trained runners during whole body cryotherapy (WBC).

Methods

Ten middle-distance runners received 3 once-a-day sessions of WBC. Subjects underwent BP measurements and ECG recorded before and immediately after the daily WBC session. During WBC we recorded a single lead trace (D1) for heart rhythm control. In addition, the 5 vital signs Blood pressure, heart rate, respiratory rate, oxygen saturation, and body temperature were monitored before, during, and after all WBC session.

Results

We did not report significant changes in ECG main intervals (PR, QT, and QTc). Mean heart rate changed from 50.98 ± 4.43 bpm (before) to 56.83 ± 4.26 bpm after WBC session (p < 0.05). The mean systolic blood pressure did not change significantly during and after WBC [b baseline: 118 ± 5 mmHg, changed to 120 ± 3 mmHg during WBC, and to 121 ± 2 mmHg after session (p < 0.05 vs. baseline)]. Mean respiratory rate did not change during WBC as well as oxygen saturations (98 vs. 99%). Body temperature was slightly increased after WBC, however it remains within physiological values

Conclusion

In non-professional athletes WBC did not affect cardiovascular response and can be safely used. However, further studies are required to confirm these promising results of safety in elderly non-athlete subjects.

The Effect of Repetitive Whole Body Cryotherapy Treatment on Adaptations to a Strength and Endurance Training Programme in Physically Active Males

Despite its potential merit in sport and exercise recovery, the implications of repetitive Whole Body Cryotherapy (WBC) during training programmes require further review due to the possibility of repetitive cold interfering with long term adaptations. This study investigated the impact of two weekly 3 min WBC sessions (30 s at −60°C, 150 s at −120°C) on adaptations to a 6 week strength and endurance training programme. Sixteen male participants (mean ± SD age 33.4 ± 9.8 years, body mass 82.3 ± 9.8 kg) randomly allocated into WBC (n = 7) and non-cryotherapy control (CON, n=9) groups completed the programme consisting of two weekly strength and plyometric training sessions and two weekly 30 min runs (70% VO₂ max). Participants were assessed for body fat, VO₂ max, muscle torque, three repetition maximum barbell squat and countermovement jump height before and after the programme. Resistance and running intensities were progressed after 3 weeks. Participants in both groups significantly improved muscle torque (WBC: 277.1 ± 63.2 Nm vs. 318.1 ± 83.4 Nm, p < 0.01, d = 0.56; CON: 244.6 ± 50.6 Nm vs. 268.0 ± 71.8 Nm, p = 0.05, d = 0.38) and barbell squat (WBC: 86.4 ± 19.5 kg vs. 98.9 ± 15.2 kg, p = 0.03, d = 0.69; CON: 91.1 ± 28.7 kg vs. 106.1 ± 30.0 kg, p < 0.01, d=0.51) following the 6 week programme. For the CON group, there was also a significant reduction in body fat percentage (p = 0.01) and significant increase in jump height (p = 0.01). There was no significant increase in VO₂ max for either group (both p > 0.2). There was no difference between WBC and CON for responses in muscle torque, 3RM barbell squat and body fat, however WBC participants did not increase their jump height (p = 0.23). Repetitive WBC does not appear to blunt adaptations to a concurrent training programme, although there may be an interference effect in the development of explosive power. Sports practitioners can cautiously apply repetitive WBC to support recovery post-exercise without undue concern on athletes' fitness gains or long term performance, particularly throughout training phases focused more on general strength development than explosive power.

Cryostimulation for Post-exercise Recovery in Athletes: A Consensus and Position Paper

Recovery after exercise is a crucial key in preventing muscle injuries and in speeding up the processes to return to homeostasis level. There are several ways of developing a recovery strategy with the use of different kinds of traditional and up-to-date techniques. The use of cold has traditionally been used after physical exercise for recovery purposes. In recent years, the use of whole-body cryotherapy/cryostimulation (WBC; an extreme cold stimulation lasting 1-4 min and given in a cold room at a temperature comprised from -60 to -195°C) has been tremendously increased for such purposes. However, there are controversies about the benefits that the use of this technique may provide. Therefore, the main objectives of this paper are to describe what is whole body cryotherapy/cryostimulation, review and debate the benefits that its use may provide, present practical considerations and applications, and emphasize the need of customization depending on the context, the purpose, and the subject's characteristics. This review is written by international experts from the working group on WBC from the International Institute of Refrigeration.

Pre-Exercise Whole- or Partial-Body Cryotherapy Exposure to Improve Physical Performance: A Systematic Review

Whole- (WBC) and partial-body cryotherapy (PBC) are commonly used sports medicine modalities for the treatment of injury and exercise recovery. Physiological and perceptual effects have the potential to be utilised in a novel application that involves pre-exercise WBC and PBC exposure to improve physical performance. A systematic literature search of multiple databases was conducted in July 2021 to identify and evaluate the effects of pre-exercise exposure of WBC or PBC on physical performance measures, and any potential translational effects. The following inclusion criteria were applied: (1) use of WBC or PBC exposure pre-exercise, (2) use of WBC or PBC in healthy and/or athletic populations, (3) control group was used in the data collection, and (4) investigated physiological, psychosocial or direct physical performance impacts of pre-exercise cryotherapy exposure. A total of 759 titles were identified, with twelve relevant studies satisfying the inclusion criteria after full-text screening. The twelve studies were categorised into three key areas: performance testing (n = 6), oxidative stress response (n = 4) and lysosomal enzyme activity (n = 2). The potential for eliciting favourable physical and physiological responses from pre-exercise WBC or PBC is currently unclear with a paucity of good quality research available. Furthermore, a lack of standardisation of cryotherapy protocols is a current challenge.

Acute Local Cooling to the Lower Body during Recovery Does Not Improve Repeated Vertical Jump Performance

BACKGROUND: Local cooling, or cryotherapy, has received attention due to its effects on athlete recovery before or after strenuous exercise. This study seeks to verify the effectiveness of 3 min applications of acute local cooling to the lower extremities between sets of a repeated vertical jump exercise. METHODS: Using a randomized crossover design, twelve subjects performed a total of 3 sets of 30 consecutive maximal vertical jumps and were allowed a recovery period of 5 min after each set. In the recovery period, subjects rested with or without a cooling suit worn on their lower legs. Changes in heart rate, blood lactate, and rate of perceived exertion were assessed. RESULTS: Vertical jump performance steadily decreased during 30 consecutive vertical jumps in all 3 sets; however, no differences in jump performance were observed among the groups. Heart rate, blood lactate, and rate of perceived exertion tended to be lower in the cooling recovery group relative to the control group. CONCLUSION: The current study provides evidence that acute local cooling recovery after a vertical jump exercise may not add any performance benefits but may provide a psychological benefit. The effectiveness of acute local cooling in other functional performances should be addressed in further research.

Effects of Focal Knee Joint Cooling on Static and Dynamic Strength of the Quadriceps: Innovative Approach to Muscle Conditioning

Recent evidence suggests an innovative approach to muscle conditioning: focal knee joint cooling (FKJC) appears to improve quadriceps function, including static (isometric) strength. However, there is limited evidence on the effects of FKJC on dynamic (concentric and eccentric) strength. Thus, the purpose of the study was to examine dynamic quadriceps strength following FKJC as well as static strength. Twenty-one college-aged participants volunteered. They randomly underwent 20 min of FKJC and control condition at least 72 h apart. FKJC involves two ice bags, placed on the anterior and posterior surfaces of the knee, whereas the control condition received a plastic ice bag filled with candy corn. We assessed isometric and isokinetic (concentric and eccentric) quadriceps strength at two different velocities (60°/s and 180°/s). Participants performed three maximal voluntary contractions for each mode of muscle contraction, before and after each treatment (immediately, 20, and 40 min after). The outcome variable was maximum knee extension peak torque. FKJC did not change peak torque during any mode of muscle contraction (p > 0.05). The current findings suggest that 20 min of FKJC does not change static (isometric) or dynamic (isokinetic) strength of the quadriceps. FKJC was neither beneficial nor harmful to static or dynamic muscular strength.

The Effects of Age and Body Fat Content on Post-Downhill Run Recovery Following Whole Body Cryotherapy

This study explored the effects of age and body fat content on responses to whole body cryotherapy (WBC) following a downhill running bout. Forty-one male participants (mean ± SD age 42.0 ± 13.7 years, body mass 75.2 ± 10.8 kg) were allocated into WBC (n = 26) and control (CON, n = 15) groups. WBC participants were divided into old (OLD, ≥45 years, n = 10) and young (YNG, <40 years, n = 13), as well as high fat (HFAT, ≥20%, n = 10) and low fat (LFAT ≤ 15%, n = 8) groups. Participants completed a 30 min downhill run (15% gradient) at 60% VO2 max. The WBC group underwent cryotherapy (3 min, -120 °C) 1 h post-run and CON participants passively recovered in a controlled environment (20 °C). Maximal isometric leg muscle torque was assessed pre and 24 h post-run. Blood creatine kinase (CK) and muscle soreness were assessed pre, post, one hour and 24 h post-run. Muscle torque significantly decreased in both groups post-downhill run (WBC: 220.6 ± 61.4 Nm vs. 208.3 ± 67.6 Nm, p = 0.02; CON: 239.7 ± 51.1 Nm vs. 212.1 ± 46.3 Nm, p = 0.00). The mean decrease in WBC was significantly less than in CON (p = 0.04). Soreness and CK increased 24 h post for WBC and CON (p < 0.01) with no difference between groups. Muscle torque significantly decreased in OLD participants (p = 0.04) but not in YNG (p = 0.55). There were no differences between HFAT and LFAT (all p values > 0.05). WBC may attenuate muscle damage and benefit muscle strength recovery following eccentrically biased exercises, particularly for young males.

Effects of whole-body cryotherapy on the innate and adaptive immune response in cyclists and runners

The study aimed to identify the effects of whole-body cryotherapy (WBC) on immunological, hormonal, and metabolic responses of non-professional male athletes. Ten cyclists and ten middle-distance runners received 3 once-a-day sessions of WBC. Before initiating and after the final WBC session, a full set of hematologic parameters, serum chemistry profile, hormones, circulating mitochondrial (mt) DNA levels, cytokines, and chemokines concentration were evaluated. The phenotype of monocyte, T cells, and B cells was analyzed. mRNA expression of 6 genes involved in inflammasome activation (NAIP, AIM2, NLRP3, PYCARD, IL-1β, and IL-18) was quantified. WBC reduced glucose and C and S protein and increased HDL, urea, insulin-like growth factor (IGF)-1, follicle-stimulating hormone, IL-18, IL-1RA, CCL2, and CXCL8. Intermediate and non-classical monocyte percentages decreased, and the CD14, CCR5, CCR2, and CXCR4 expressions changed in different subsets. Only IL-1β mRNA increased in monocytes. Finally, a redistribution of B and T cell subsets was observed, suggesting the migration of mature cells to tissue. WBC seems to induce changes in both innate and adaptive branches of the immune system, hormones, and metabolic status in non-professional male athletes, suggesting a beneficial involvement of WBC in tissue repair.

Effects of acute cooling on cycling anaerobic exercise performance and neuromuscular activity: a randomized crossover study

BACKGROUND

While cryotherapy is known for its favorable long-term recovery effects on muscle-damaging eccentric and plyometric exercises, studies showed that cryotherapy when used as an acute recovery mode (same day) had a negligible or negative effect on high-intensity and explosive exercises. However, there is lack of evidence regarding the mechanisms underlying the detrimental effect of acute cooling on the anaerobic performance. We hypothesized that acute cooling for the lower body would reduce anaerobic power output during a subsequent Wingate anaerobic tests (WAnT), which is at least in part due to decreased neuromuscular firing rate as indexed by mean frequency.

METHODS

We performed a randomized crossover design experiment. Eleven young healthy males completed two consecutive 30-sec Wingate anaerobic tests (WAnT 1 and 2). Subjects rested for 10 min between the WAnT 1 and the WAnT 2. Neuromuscular activity on the rectus femoris of both legs was recorded using wireless electromyography (EMG) during WAnT.

RESULTS

Anaerobic power during the first 5 sec of WAnT 2 was decreased in the cooling suit recovery group relative to WAnT 1. Mean frequency (MNF) in WAnT 2 was also lower in a cooled leg during WAnT 2 during the first 10 sec when compared with WAnT 1.

CONCLUSIONS

Acute cooling application blunts the initial phase of anaerobic power output during a subsequent WAnT, which could be explained by a concomitant reduction in neuromuscular firing rate. Given that cryotherapy is widely utilized in a variety of sports, athletes and trainers should pay close attention to the appropriate application of cryotherapy.

Effects of whole-body cryotherapy on 25-hydroxyvitamin D, irisin, myostatin, and interleukin-6 levels in healthy young men of different fitness levels

Skeletal muscle and adipose tissue play an important role in maintaining metabolic homeostasis and thermogenesis. We aimed to investigate the effects of single and repeated exposure to whole-body cryotherapy in volunteers with different physical fitness levels on 25-hydroxyvitamin D (25(OH)D) and myokines. The study included 22 healthy male volunteers (mean age: 21 ± 1.17 years), who underwent 10 consecutive sessions in a cryogenic chamber once daily (3 minutes, −110 °C). Blood samples were collected before and 30 minutes and 24 hours after the first and last cryotherapy sessions. Prior to treatment, body composition and physical fitness levels were measured. After 10 cryotherapy treatments, significant changes were found in myostatin concentrations in the low physical fitness level (LPhL) group. The 25(OH)D levels were increased in the high physical fitness level (HPhL) group and decreased in the LPhL group. The HPhL group had significant changes in the level of high-sensitivity interleukin-6 after the first treatment. The LPhL group had significant changes in 25(OH)D, irisin, and myostatin levels after the tenth treatment. Our data demonstrated that in healthy young men, cryotherapy affects 25(OH)D levels, but they were small and transient. The body’s response to a series of 10 cryotherapy treatments is modified by physical fitness level.