Cold water immersion improves recovery of sprint speed following a simulated tournament

Cold Water Immersion Does Not Enhance Recovery and Performance After High-Intensity Interval Dorsiflexion Exercise

Cold-water immersion (CWI) has become a widely adopted method for post-exercise recovery. However, its effectiveness in restoring neuromuscular function remains inconclusive. This study examined the impact of CWI on recovery following high-intensity interval exercise (HIIE). Twelve young, recreationally active individuals (10 males, 2 females) participated in a randomized crossover study. Each session included six sets of 30-s all-out isokinetic concentric contractions of the ankle dorsiflexor and plantar flexor muscles, followed by 10 min of room temperature rest (RT) or CWI at 10°C. Neuromuscular function and intramuscular temperature were evaluated periodically over 24 h, as well as next-day fatigue resistance of the dorsiflexors. In both conditions, maximal voluntary contraction torque remained impaired for up to 3 h without significant changes in voluntary activation (p > 0.05). Electrically stimulated torque showed no difference in the fatigue-induced decline or recovery of 10 Hz torque, which also remained impaired for up to 3 h. However, 50 Hz torque recovered within 1 h following RT, whereas it remained slightly reduced for up to 3 h following CWI. The 10:50 Hz torque ratio showed immediate recovery with CWI, whereas RT recovery was delayed for up to 1 h. Notably, the ratio was significantly lower with RT at 0-, 0.5-, and 1-h post-intervention. Despite these differences, HIIE performance during a repeat bout conducted 24 h later remained similar. In conclusion, 10 min of CWI at 10°C does not enhance post-exercise recovery or next-day exercise performance following HIIE.

The untapped potential of cold water therapy as part of a lifestyle intervention for promoting healthy aging

Healthy aging is a crucial goal in aging societies of the western world, with various lifestyle strategies being employed to achieve it. Among these strategies, hydrotherapy stands out for its potential to promote cardiovascular and mental health. Cold water therapy, a hydrotherapy technique, has emerged as a lifestyle strategy with the potential capacity to evoke a wide array of health benefits. This review aims to synthesize the extensive body of research surrounding cold water therapy and its beneficial effects on various health systems as well as the underlying biological mechanisms driving these benefits. We conducted a search for interventional and observational cohort studies from MEDLINE and EMBASE up to July 2024. Deliberate exposure of the body to cold water results in distinct physiological responses that may be linked to several health benefits. Evidence, primarily from small interventional studies, suggests that cold water therapy positively impacts cardiometabolic risk factors, stimulates brown adipose tissue and promotes energy expenditure-potentially reducing the risk of cardiometabolic diseases. It also triggers the release of stress hormones, catecholamines and endorphins, enhancing alertness and elevating mood, which may alleviate mental health conditions. Cold water therapy also reduces inflammation, boosts the immune system, promotes sleep and enhances recovery following exercise. The optimal duration and temperature needed to derive maximal benefits is uncertain but current evidence suggests that short-term exposure and lower temperatures may be more beneficial. Overall, cold water therapy presents a potential lifestyle strategy to enhancing physical and mental well-being, promoting healthy aging and extending the healthspan, but definitive interventional evidence is warranted.

A evidence-based approach to selecting post-exercise cryostimulation techniques for improving exercise performance and fatigue recovery: A systematic review and meta-analysis

Rationale

Cryostimulation involves using water environments and low temperatures as intervention mediums, with main methods including CWI (cold water immersion), CWT (contrast water therapy), and WBC (whole-body cryostimulation). Previous systematic reviews focused on the effect of cryostimulation on muscle fatigue and sports performance. However, studies on the selection of different cryostimulation methods and their intervention effects present inconsistent results.

Introduction

To systematically review and methodologically appraise the quality and effectiveness of existing intervention studies that the effects of various cryostimulation methods, including CWI, CWT, and WBC, on exercise performance and fatigue recovery.

Methods

Following PRISMA guidelines, we conducted searches in PubMed, Embase, The Cochrane Library, Web of Science, and EBSCO databases to gather randomized controlled trials or self-controlled trials involving CWI/CWT/WBC and their effects on exercise performance or fatigue recovery. The search period ranged from November 2013 to November 2, 2023. Literature screening was performed using EndNote X9.1, and the quality of included studies was assessed using the Cochrane risk of bias assessment tool. Meta-analysis was conducted using RevMan 5.3 software.

Results

This study included a total of 18 articles, included a total of 499 healthy participants, comprising 479 males and 20 females. Among them, participants underwent cryostimulation, including 102 using CWT, using CWI, and 58 using WBC. Compared to the control group, cryostimulation can significantly alleviate muscle pain intensity (SMD -0.45, 95% CL -0.82 to 0.09, P = 0.01). Specifically, CWI significantly reduced muscle pain intensity (SMD = -0.45, 95% CI: 0.820.09, P = 0.01), WBC significantly decreased C-reactive protein levels (SMD = -1.36, 95% CI: 2.350.36, P = 0.008). While, CWT showed no significant differences from the control group in exercise performance and fatigue recovery indicators (P > 0.05).

Conclusion

Cryostimulation can significantly reduce muscle pain intensity and perceived fatigue. Specifically, CWI significantly alleviates muscle pain intensity, WBC significantly lowers markers of inflammation caused by fatigue after exercise, in contrast, CWT does not significantly improve exercise performance and fatigue recovery. After exercise, compared with rest, using cryostimulation may have more noticeable benefits for muscle fatigue and muscle pain, with recommendations prioritizing WBC and CWI particularly for addressing inflammation and muscle pain. However, all cryostimulation may have no significant influence on exercise performance.

Effect of repeatedly applied cold water immersion on subclinical atherosclerosis, inflammation, fat accumulation and lipid profile parameters of volunteers

Significant acute cardiovascular, metabolic, and endocrine changes have been traced to short-lasting cold water immersion (CWI); however, the long-term impact of recurrent CWI on atherogenesis, lipid parameters, and fat distribution has not yet been studied. The goal of this study was to investigate the alleged protective effect. A total of 35 healthy volunteers were monitored for a period of 5 months during which the CWI was performed under standardized conditions (three times per week for 7-10 min, without neoprene equipment). Volunteers with measured weight or muscle mass increases of more than 5% were ineligible. An analogous control group (N = 30) was included. At the onset and completion of the study, blood samples were obtained, and clinical assessments took place. PCSK9 and hsCRP levels were measured together with other lipid-related and non-lipid-related indicators. Carotid intima-media thickness test (cIMT) and echo-tracking for the identification of arterial stiffness (PWV, AI, and β) were used to identify early vascular alterations. Hepatorenal index (HRI) calculations served to quantify liver steatosis, while changes in subcutaneous and visceral fat thickness were used to quantify fat distribution. The given protocol was successfully completed by 28 volunteers. Long-term repeated CWI resulted in a significant decline in cIMT (p = 0.0001), AI (p = 0.0002), Beta (p = 0.0001), and PWV (p = 0.0001). PCSK9 (p = 0.01) and hsCRP (p = 0.01) showed a significant decrease when compared to initial values. In comparison to the starting values, liver fat accumulation decreased by 11% on average (HRI p = 0.001). LDL, TC, TG, and VLDL levels all significantly decreased as well. We suggest that repeated CWI may have beneficial impact on lipid, non-lipid, and lipid-related indices, as well as atherogenesis and liver fat storage.

Cold-water immersion and whole-body cryotherapy attenuate muscle soreness during 3 days of match-like tennis protocol

PURPOSE

This study aimed to investigate the effect of whole-body cryotherapy (WBC), cold-water immersion (CWI) and passive recovery (PAS) on tennis recovery.

METHODS

Thirteen competitive male tennis players completed three consecutive match-like tennis protocols, followed by recovery (WBC, CWI, PAS) in a crossover design. Five tennis drills and serves were performed using a ball machine to standardize the fatiguing protocol. Maximal voluntary contraction (MVC) peak torque, creatine kinase activity (CK), muscle soreness, ball accuracy and velocity together with voluntary activation, low- and high-frequency torque and EMG activity were recorded before each protocol and 24 h following the third protocol.

RESULTS

MVC peak torque (- 7.7 ± 11.3%; p = 0.001) and the high- to low-frequency torque ratio (- 10.0 ± 25.8%; p < 0.05) decreased on Day 1 but returned to baseline on Day 2, Day 3 and Day 4 (p = 0.052, all p > 0.06). The CK activity slightly increased from 161.0 ± 100.2 to 226.0 ± 106.7 UA L-1 on Day 1 (p = 0.001) and stayed at this level (p = 0.016) across days with no differences between recovery interventions. Muscle soreness increased across days with PAS recovery (p = 0.005), while no main effect of time was neither observed with WBC nor CWI (all p > 0.292). The technical performance was maintained across protocols with WBC and PAS, while it increased for CWI on Day 3 vs Day 1 (p = 0.017).

CONCLUSION

Our 1.5-h tennis protocol led to mild muscle damage, though neither the neuromuscular function nor the tennis performance was altered due to accumulated workload induced by consecutive tennis protocols. The muscle soreness resulting from tennis protocols was similarly alleviated by both CWI and WBC.

TRIAL REGISTRATION

IRB No. 2017-A02255-48, 12/05/2017.

The effect of cold water immersion on the recovery of physical performance revisited: A systematic review with meta-analysis

This review evaluated the effect of CWI on the temporal recovery profile of physical performance, accounting for environmental conditions and prior exercise modality. Sixty-eight studies met the inclusion criteria. Standardised mean differences were calculated for parameters assessed at <1, 1-6, 24, 48, 72 and ≥96 h post-immersion. CWI improved short-term recovery of endurance performance (p = 0.01, 1 h), but impaired sprint (p = 0.03, 1 h) and jump performance (p = 0.04, 6h). CWI improved longer-term recovery of jump performance (p < 0.01-0.02, 24 h and 96 h) and strength (p < 0.01, 24 h), which coincided with decreased creatine kinase (p < 0.01-0.04, 24-72 h), improved muscle soreness (p < 0.01-0.02, 1-72 h) and perceived recovery (p < 0.01, 72 h). CWI improved the recovery of endurance performance following exercise in warm (p < 0.01) and but not in temperate conditions (p = 0.06). CWI improved strength recovery following endurance exercise performed at cool-to-temperate conditions (p = 0.04) and enhanced recovery of sprint performance following resistance exercise (p = 0.04). CWI seems to benefit the acute recovery of endurance performance, and longer-term recovery of muscle strength and power, coinciding with changes in muscle damage markers. This, however, depends on the nature of the preceding exercise.

What Parameters Influence the Effect of Cold-Water Immersion on Muscle Soreness? An Updated Systematic Review and Meta-Analysis

OBJECTIVE

Our objective was to determine the efficacy of cold-water immersion (CWI) on the management of muscle soreness to identify the impact of immersion time, water temperature, CWI protocol, and type of exercise on this outcome.

DESIGN

Intervention systematic review and meta-analysis.

SETTING

MEDLINE/PubMed, Embase, Central, and SPORTDiscus databases were searched from their earliest record to July 30, 2020. Only randomized controlled trials that assessed muscle soreness comparing CWI and control were included. Studies were pooled in different subgroups regarding the used protocol: water temperature (severe or moderate cold), immersion time (short, medium, or longer time), CWI protocol (intermittent or continuous application), and type of exercise (endurance or resistance exercise). Data were pooled in a meta-analysis and described as weighted mean difference (95% confidence interval, P < 0.05).

PARTICIPANTS

Athletes and nonathletes.

INTERVENTIONS

Cold-water immersion and control condition.

MAIN OUTCOME MEASURES

Muscle soreness.

RESULTS

Forty-four studies were included. For immediate effects, CWI was superior to control regardless of water temperature and protocol, and for short and medium immersion times and endurance exercises. For delayed effects, CWI was superior to control in all subgroups except longer immersions time.

CONCLUSIONS

This study suggests that CWI is better than control for the management of muscle soreness and water temperature and CWI protocol do not influence this result, but only short and medium immersions times presented positive effects. Aiming immediate effects, the best results suggest CWI application only after endurance exercises, while delayed effect CWI was superior both after endurance and resistance exercises.

Cold water immersion after a soccer match: Does the placebo effect occur?

Although cold water immersion (CWI) is one of the most widely used post-exercise strategies to accelerate recovery processes, the benefits of CWI may be associated with placebo effects. This study aimed to compare the effects of CWI and placebo interventions on time course of recovery after the Loughborough Intermittent Shuttle Test (LIST). In a randomized, counterbalanced, crossover study, twelve semi-professional soccer players (age 21.1 ± 2.2 years, body mass 72.4 ± 5.9 kg, height 174.9 ± 4.6 cm, V ˙ O_2max 56.1 ± 2.3 mL/min/kg) completed the LIST followed by CWI (15 min at 11°C), placebo (recovery Pla beverage), and passive recovery (Rest) over three different weeks. Creatine kinase (CK), C-reactive protein (CRP), uric acid (UA), delayed onset muscle soreness (DOMS), squat jump (SJ), countermovement jump (CMJ), 10-m sprint (10 mS), 20-m sprint (20 mS) and repeated sprint ability (RSA) were assessed at baseline and 24 and 48 h after the LIST. Compared to baseline, CK concentration was higher at 24 h in all conditions (p < 0.01), while CRP was higher at 24 h only in CWI and Rest conditions (p < 0.01). UA was higher for Rest condition at 24 and 48 h compared to Pla and CWI conditions (p < 0.001). DOMS score was higher for Rest condition at 24 h compared to CWI and Pla conditions (p = 0.001), and only to Pla condition at 48 h (p = 0.017). SJ and CMJ performances decreased significantly after the LIST in Rest condition (24 h: -7.24%, p = 0.001 and -5.45%, p = 0.003 respectively; 48 h: -9.19%, p < 0.001 and -5.70% p = 0.002 respectively) but not in CWI and Pla conditions. 10 mS and RSA performance were lower for Pla at 24 h compared to CWI and Rest conditions (p < 0.05), while no significant change was observed for 20 mS time. These data suggests that CWI and Pla intervention were more effective than the Rest conditions in recovery kinetics of muscle damage markers and physical performance. Furthermore, the effectiveness of CWI would be explained, at least in part, by the placebo effect.

Health effects of voluntary exposure to cold water - a continuing subject of debate

This review is based on a multiple database survey on published literature to determine the effects on health following voluntary exposure to cold-water immersion (CWI) in humans. After a filtering process 104 studies were regarded relevant. Many studies demonstrated significant effects of CWI on various physiological and biochemical parameters. Although some studies were based on established winter swimmers, many were performed on subjects with no previous winter swimming experience or in subjects not involving cold-water swimming, for example, CWI as a post-exercise treatment. Clear conclusions from most studies were hampered by the fact that they were carried out in small groups, often of one gender and with differences in exposure temperature and salt composition of the water. CWI seems to reduce and/or transform body adipose tissue, as well as reduce insulin resistance and improve insulin sensitivity. This may have a protective effect against cardiovascular, obesity and other metabolic diseases and could have prophylactic health effects. Whether winter swimmers as a group are naturally healthier is unclear. Some of the studies indicate that voluntary exposure to cold water has some beneficial health effects. However, without further conclusive studies, the topic will continue to be a subject of debate.

Effect of 3 min whole-body and lower limb cold water immersion on subsequent performance of agility, sprint, and intermittent endurance exercise

The aim of this study was to investigate the effects of whole-body cold-water immersion (WCWI) and lower-limb cold-water immersion (LCWI) employed during a 15-min recovery period on the subsequent exercise performance as well as to determine the physiological and perceptual parameters in the heat (39°C). Eleven males performed team-sports-specific tests outdoors. The exercise program consisted of two identical exercise protocols (1 and 2) separated by a 15-min recovery period. The participants completed the same tests in each exercise protocol, in the following order: agility t test (t-test), 20-m sprint test (20M-ST), and Yo-Yo Intermittent Endurance Test Level 1 (Yo-Yo). During the recovery period, a 3-min recovery intervention of a passively seated rest (control, CON), WCWI, or LCWI was performed. The t-test and 20M-ST for the CON group were significantly longer during exercise protocol 2, but they were not significantly different between the two exercise protocols for the WCWI and LCWI groups. The completed Yo-Yo distance for the CON and LCWI groups was shorter during exercise protocol 2, but it was not significantly different between the two exercise protocols for the WCWI group. The chest temperature (Tchest), upper arm temperature (Tarm), thigh temperature (Tthigh), mean skin temperature (Tskin), and thermal sensation (TS) values were lower for the WCWI group than for the CON group; but only the Tthigh, Tskin, and TS values were lower for the LCWI group compared to the CON group. The Tchest, Tarm, Tskin, and TS values after the intervention were lower for the WCWI group than for the LCWI group. None of the three intervention conditions affected the core temperature (Tcore), heart rate (HR), or rating of perceived exertion (RPE). These results suggest that WCWI at 15°C for 3 min during the 15-min recovery period attenuates the impairment of agility, sprint, and intermittent-endurance performance during exercise protocol 2, but LCWI only ameliorates the reduction of agility and sprint performance. Furthermore, the ergogenic effects of WCWI and LCWI in the heat are due, at least in part, to a decrease of the Tskin and improvement of perceived strain.

The Physiological Profile Following Two Popular Cold Interventions After Activity in Hot and Humid Environment

This research aims to describe and compare the effects of partial-body cryotherapy (PBC) and cold-water immersion (CWI) on the physiological responses of soccer players after cycling in a hot and humid environment. Sixteen elite soccer players participated in three experiments, and received CWI (13°C for 15 min), PBC (110°C−140°C for 3 min), and CON (room temperature: 21°C ± 2°C), respectively, after aerobic and anaerobic cycling in a hot and humid environment (temperature: 35°C–38°C; humidity: 60%–70%). Heart rate (HR), blood lactate (BLa-), perfusion index (PI), oxygen saturation (SaO₂), core temperature (Tc), skin temperature (Ts), and rating of perceived exertion (RPE) were assessed at baseline and through 20 min (5-min intervals). HR was lower in CWI than CON after 20 min (p < .05). SaO₂ was higher in CWI than PBC and CON between 10 and 20 min (p < .05). Tc was lower from CWI and PBC than CON between 10 and 20 min (p < .05). Ts was lower in PBC than CWI between 15 and 20 min (p < .05). RPE was lower in PBC than CON 20 min after the exercise (p < .05). No main group differences for BLa- and PI were observed. The physiological effects of PBC are generally similar to CWI. Compared with CON, both CWI and PBC could promote the recovery of physiological indexes within 20 min of exercise in a hot and humid environment. However, PBC can lead to a decrease in SaO₂ due to excessive nitrogen inhalation.

Impact of Cold-Water Immersion Compared with Passive Recovery Following a Single Bout of Strenuous Exercise on Athletic Performance in Physically Active Participants: A Systematic Review with Meta-analysis and Meta-regression

Background

Studies investigating the effects of cold-water immersion (CWI) on the recovery of athletic performance, perceptual measures and creatine kinase (CK) have reported mixed results in physically active populations.

Objectives

The purpose of this systematic review was to investigate the effects of CWI on recovery of athletic performance, perceptual measures and CK following an acute bout of exercise in physically active populations.

Study Design

Systematic review with meta-analysis and meta-regression.

Methods

A systematic search was conducted in September 2021 using Medline, SPORTDiscus, Scopus, Web of Science, Cochrane Library, EmCare and Embase databases. Studies were included if they were peer reviewed and published in English, included participants who were involved in sport or deemed physically active, compared CWI with passive recovery methods following an acute bout of strenuous exercise and included athletic performance, athlete perception and CK outcome measures. Studies were divided into two strenuous exercise subgroups: eccentric exercise and high-intensity exercise. Random effects meta-analyses were used to determine standardised mean differences (SMD) with 95% confidence intervals. Meta-regression analyses were completed with water temperature and exposure durations as continuous moderator variables.

Results

Fifty-two studies were included in the meta-analyses. CWI improved the recovery of muscular power 24 h after eccentric exercise (SMD 0.34 [95% CI 0.06–0.62]) and after high-intensity exercise (SMD 0.22 [95% CI 0.004–0.43]), and reduced serum CK (SMD − 0.85 [95% CI − 1.61 to − 0.08]) 24 h after high-intensity exercise. CWI also improved muscle soreness (SMD − 0.89 [95% CI − 1.48 to − 0.29]) and perceived feelings of recovery (SMD 0.66 [95% CI 0.29–1.03]) 24 h after high-intensity exercise. There was no significant influence on the recovery of strength performance following either eccentric or high-intensity exercise. Meta-regression indicated that shorter time and lower temperatures were related to the largest beneficial effects on serum CK (duration and temperature dose effects) and endurance performance (duration dose effects only) after high-intensity exercise.

Conclusion

CWI was an effective recovery tool after high-intensity exercise, with positive outcomes occurring for muscular power, muscle soreness, CK, and perceived recovery 24 h after exercise. However, after eccentric exercise, CWI was only effective for positively influencing muscular power 24 h after exercise. Dose–response relationships emerged for positively influencing endurance performance and reducing serum CK, indicating that shorter durations and lower temperatures may improve the efficacy of CWI if used after high-intensity exercise.

Funding

Emma Moore is supported by a Research Training Program (Domestic) Scholarship from the Australian Commonwealth Department of Education and Training.

Protocol registration

Open Science Framework: 10.17605/OSF.IO/SRB9D.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40279-022-01644-9.

The cold truth: the role of cryotherapy in the treatment of injury and recovery from exercise

Cryotherapy is utilized as a physical intervention in the treatment of injury and exercise recovery. Traditionally, ice is used in the treatment of musculoskeletal injury while cold water immersion or whole-body cryotherapy is used for recovery from exercise. In humans, the primary benefit of traditional cryotherapy is reduced pain following injury or soreness following exercise. Cryotherapy-induced reductions in metabolism, inflammation, and tissue damage have been demonstrated in animal models of muscle injury; however, comparable evidence in humans is lacking. This absence is likely due to the inadequate duration of application of traditional cryotherapy modalities. Traditional cryotherapy application must be repeated to overcome this limitation. Recently, the novel application of cooling with 15 °C phase change material (PCM), has been administered for 3-6 h with success following exercise. Although evidence suggests that chronic use of cryotherapy during resistance training blunts the anabolic training effect, recovery using PCM does not compromise acute adaptation. Therefore, following exercise, cryotherapy is indicated when rapid recovery is required between exercise bouts, as opposed to after routine training. Ultimately, the effectiveness of cryotherapy as a recovery modality is dependent upon its ability to maintain a reduction in muscle temperature and on the timing of treatment with respect to when the injury occurred, or the exercise ceased. Therefore, to limit the proliferation of secondary tissue damage that occurs in the hours after an injury or a strenuous exercise bout, it is imperative that cryotherapy be applied in abundance within the first few hours of structural damage.

Effect of cold water immersion on muscle damage indexes after simulated soccer training in young soccer players

Study aim: To investigate the effect of cold water immersion (CWI) on muscle damage indexes after simulated soccer activity in young soccer players.

Material and methods: Eighteen professional male soccer players were randomly divided into two groups: CWI (n = 10, age 19.3 ± 0.5, body mass index 22.2 ± 1.3) and control (n = 8, age 19.4 ± 0.8, body mass index 21.7 ± 1.5). Both groups performed a simulated 90-minute soccer-specific aerobic field test (SAFT90). Then, the CWI group subjects immersed themselves for 10 minutes in 8°C water, while the control group subjects sat passively for the same time period. Blood samples were taken before, immediately after, 10 minutes, 24 hours and 48 hours after the training session in a fasted state. Blood lactate, creatine kinase (CK) and lactate dehydrogenase (LDH) enzyme levels were measured.

Results: Lactate, CK and LDH levels increased significantly after training (p < 0.001). There were significant interactions between groups and subsequent measurements for CK (p = 0.0012) and LDH (p = 0.0471). There was no significant difference in lactate level between the two groups at any aforementioned time.

Conclusion: It seems that CWI after simulated 90-minute soccer training can reduce the values of muscle damage indexes in soccer players.

Don't Lose Your Cool With Cryotherapy: The Application of Phase Change Material for Prolonged Cooling in Athletic Recovery and Beyond

Strenuous exercise can result in muscle damage in both recreational and elite athletes, and is accompanied by strength loss, and increases in soreness, oxidative stress, and inflammation. If the aforementioned signs and symptoms associated with exercise-induced muscle damage are excessive or unabated, the recovery process becomes prolonged and can result in performance decrements; consequently, there has been a great deal of research focussing on accelerating recovery following exercise. A popular recovery modality is cryotherapy which results in a reduction of tissue temperature by the withdrawal of heat from the body. Cryotherapy is advantageous because of its ability to reduce tissue temperature at the site of muscle damage. However, there are logistical limitations to traditional cryotherapy modalities, such as cold-water immersion or whole-body cryotherapy, because they are limited by the duration for which they can be administered in a single dose. Phase change material (PCM) at a temperature of 15°C can deliver a single dose of cooling for a prolonged duration in a practical, efficacious, and safe way; hence overcoming the limitations of traditional cryotherapy modalities. Recently, 15°C PCM has been locally administered following isolated eccentric exercise, a soccer match, and baseball pitching, for durations of 3-6 h with no adverse effects. These data showed that using 15°C PCM to prolong the duration of cooling successfully reduced strength loss and soreness following exercise. Extending the positive effects associated with cryotherapy by prolonging the duration of cooling can enhance recovery following exercise and give athletes a competitive advantage.

Effects of Hyperbaric Oxygen Therapy on Inflammation, Oxidative/Antioxidant Balance, and Muscle Damage after Acute Exercise in Normobaric, Normoxic and Hypobaric, Hypoxic Environments: A Pilot Study

The purpose of this study was to investigate the effects of hyperbaric oxygen therapy (HBOT) on inflammation, the oxidative/antioxidant balance, and muscle damage after acute exercise in normobaric, normoxic (NN) and hypobaric, hypoxic (HH) environments. Eighteen healthy males were selected and randomly assigned to three groups: exercise in NN conditions (NN group, n = 6), HBOT treatment after exercise in NN conditions (HNN group, n = 6), and HBOT treatment after exercise in HH conditions (HHH group, n = 6). All subjects performed treadmill running for 60 min at 75–80% maximum heart rate (HRmax) exercise intensity under each condition. The HBOT treatments consisted of breathing 100% oxygen at 2.5 atmosphere absolute (ATA) for 60 min. Blood samples were collected before exercise (BE), after exercise (AE), and after HBOT (AH) to examine inflammation (fibrinogen, interleukin-6 [IL-6], and tumor necrosis factor-α (TNF-α)), the oxidative/antioxidant balance (derivatives of reactive oxygen metabolites (d-ROMs) and the biological antioxidant potential (BAP)), and muscle damage (creatine kinase (CK) and lactate dehydrogenase (LDH)). Plasma fibrinogen, serum IL-6, CK, and LDH levels were significantly increased AE compared to BE in all groups (p < 0.05). Plasma fibrinogen levels were significantly decreased AH compared to AE in all groups (p < 0.05), and the HNN group had a significantly lower AH compared to BE (p < 0.05). Serum IL-6 levels were significantly decreased AH compared to AE in the HNN and HHH groups (p < 0.05). Serum CK levels were significantly decreased AH compared to AE in the HHH group (p < 0.05). Serum LDH levels were significantly decreased AH compared to AE in the HNN and HHH groups (p < 0.05), and the NN and HNN groups had significantly higher AH serum LDH levels compared to BE (p < 0.05). These results suggest that acute exercise in both the NN and HH environments could induce temporary inflammatory responses and muscle damage, whereas HBOT treatment may be effective in alleviating exercise-induced inflammatory responses and muscle damage.