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Background: Cryotherapy has been widely used for post-exercise recovery for decades. Whole-body cryotherapy (WBC) is a technique that involves brief exposure to extremely cold temperatures to produce therapeutic effects. Its effectiveness in treating exercise-induced impairments is currently under investigation. Purpose: This systematic review aims to assess whether WBC is more, less, or equally effective compared to other recovery interventions in reducing perceived muscle soreness and restoring muscle function after exercise-induced muscle damage (EIMD) in runners. Methods: A systematic literature review was conducted using the following MeSH terms: cryotherapy, whole-body cryotherapy, exercise-induced muscle damage, muscle soreness, muscle recovery, and running. The databases searched included PubMed, CINAHL, EBSCO Host, and Google Scholar. Articles were included if they were published in the last 10 years, had a level of evidence of IIb or higher according to the Centre for Evidence-Based Medicine (CEBM), a PEDro scale score of at least 5, focused on runners, and assessed both perceived muscle soreness and muscle function recovery. Studies were excluded if they did not involve runners, used partial-body cryotherapy (PBC) instead of WBC, or failed to measure both muscle performance and perceived soreness. Results: Among the four studies analyzed: • Two studies found WBC

Medicine (CEBM), a PEDro scale score of at least 5, focused on runners, and assessed both perceived muscle soreness and muscle function recovery. Studies were excluded if they did not involve runners, used partial-body cryotherapy (PBC) instead of WBC, or failed to measure both muscle performance and perceived soreness. Results: Among the four studies analyzed: • Two studies found WBC significantly more effective than other interventions, such as far-infrared radiation and passive recovery, in reducing muscle soreness and restoring muscle power and endurance following simulated trail runs and high-intensity interval running. • One study reported no significant difference between WBC and passive recovery in reducing muscle soreness and restoring muscle power after sprint intervals. • One study indicated that WBC had a negative impact compared to cold water immersion (CWI) and passive recovery, worsening both muscle soreness and muscle strength recovery after a marathon. Conclusion: The findings were inconclusive regarding WBC’s effectiveness in treating exercise-induced muscle damage in runners compared to other recovery methods. However, WBC appears to have a time-dependent positive effect on muscle recovery, particularly after high-intensity interval and endurance running—though this benefit does not extend to marathon recovery. Further research is necessary to establish optimal WBC treatment protocols, including temperature, timing, duration, and frequency. Introduction Running is one of the most widely practiced forms of cardiovascular exercise worldwide, appealing to individuals of all ages and fitness levels. It is highly versatile, encompassing activities such as sprinting, jogging, and marathon running. Despite its many health benefits, running can exert significant stress on the body, leading to injuries and exercise-induced muscle damage (EIMD) (Oja et al., 2015). ISSN 3065-7636 EIMD is a broad term describing the mechanical and metabolic effects of intense or unfamiliar exercise. These effects include muscle soreness, fatigue, weakness, swelling, impaired proprioception, and increased levels of creatine kinase and lactate in the bloodstream (Clarkson & Hubal, 2022; Proske et al., 2005). Symptoms can last from a single day to several weeks after exercise. While repeated concentric contractions can contribute to EIMD, research suggests that eccentric, or

soreness, fatigue, weakness, swelling, impaired proprioception, and increased levels of creatine kinase and lactate in the bloodstream (Clarkson & Hubal, 2022; Proske et al., 2005). Symptoms can last from a single day to several weeks after exercise. While repeated concentric contractions can contribute to EIMD, research suggests that eccentric, or

J Nurs Care Repo; 2025 www.unisciencepub.com Volume 6 | Issue 2 | 2 of 9 muscle-lengthening, contractions—common in running—are the primary cause (Venhorst et al., 2018). To optimize performance and recovery, runners commonly use various pre- and post-exercise strategies. Among these, thermotherapy (heat application) and cryotherapy (cold application) are particularly popular. Cryotherapy, which dates back thousands of years, was historically used for treating wounds, inflammation, and even tumor removal. (Freiman & Bougamin, 2005). Over time, the methods of cryotherapy application have evolved, with whole-body cryotherapy (WBC) gaining popularity in sports medicine. Whole-Body Cryotherapy (WBC) WBC involves brief exposure to extremely cold temperatures for therapeutic purposes. It was invented by Dr. Yamaguchi of Japan in 1978 who first started using freezing treatments of short duration on his Rheumatoid Arthritis patients (Costello et al., 2015). It is currently widely used in Europe with Poland having the highest number of modern cryochambers, primarily for medical use. Unlike the U.S., where cryotherapy chambers are mainly found in sports and wellness centers, Polish rehabilitation facilities commonly incorporate WBC, often under medical supervision (Jamwal, 2017). WBC chambers maintain temperatures between -110°C and -140°C using liquid nitrogen. A typical session involves the participant wearing minimal clothing (such as a swimsuit, socks, and a headband) and first spending 30 seconds in a vestibule chamber at -60°C to acclimate before entering the cryochamber for a maximum of three minutes (Lombardi et al., 2017). A trained professional must always be present to ensure safety and adherence to protocols. While numerous studies have explored the physiological effects of WBC post-exercise, the exact mechanisms underlying its therapeutic benefits remain unclear. The primary physiological response to cryotherapy is a reduction in skin temperature, leading to decreased local blood flow, swelling, metabolic activity, and nerve conduction velocity (White & Wells, 2013). These factors are believed to contribute to cryotherapy’s analgesic and anti-inflammatory effects. Research comparing local cryotherapy (ice packs, ice massage) to whole-body techniques (CWI, WBC) suggests that while ice packs are more effective at lowering skin temperature, WBC and CWI may better reduce core and deep tissue temperatures, including within muscles (White &

nerve conduction velocity (White & Wells, 2013). These factors are believed to contribute to cryotherapy’s analgesic and anti-inflammatory effects. Research comparing local cryotherapy (ice packs, ice massage) to whole-body techniques (CWI, WBC) suggests that while ice packs are more effective at lowering skin temperature, WBC and CWI may better reduce core and deep tissue temperatures, including within muscles (White & Wells, 2013). This could explain their potential effectiveness in treating EIMD. However, WBC research remains less extensive than studies on cold water immersion (CWI). Thus, the objective of this review is to evaluate WBC’s effectiveness in alleviating muscle soreness and enhancing muscle recovery in runners. Research Questions • Is WBC more, less, or equally effective in reducing perceived muscle soreness after exercise-induced muscle damage in runners compared to other recovery methods? • Is WBC more, less, or equally effective in restoring muscle function after exercise-induced muscle damage in runners compared to other recovery methods? Hypotheses • WBC will be more effective than alternative recovery methods in reducing perceived muscle soreness following exercise-induced muscle damage in runners. • WBC will be more effective than alternative recovery methods in promoting muscle function recovery in runners after exercise-induced muscle damage. Methodology Literature Search A systematic review was conducted to address the research questions. Databases searched included PubMed, CINAHL, EBSCO Host, and Google Scholar. The search incorporated the following MeSH terms: cryotherapy, whole-body cryotherapy, exercise-induced muscle damage, muscle soreness, muscle recovery, and running. Inclusion Criteria Studies were included if they • Were randomized controlled trials with free full-text access. • Were published in English within the last 10 years. • Examined both short- and long-distance runners. • Compared WBC to another recovery method or control group. • Measured at least one outcome related to muscle function or perceived muscle soreness. • Had a CEBM evidence level of 2b or higher. • Scored at least 5 on the PEDro scale, ensuring methodological quality. This structured approach ensures a high level of reliability in evaluating WBC’s effectiveness for post-run recovery. Table 1: CEBM Level of Evidence Level Research Design Level 1aSystematic Reviews of Randomized Controlled Trials

muscle function or perceived muscle soreness. • Had a CEBM evidence level of 2b or higher. • Scored at least 5 on the PEDro scale, ensuring methodological quality. This structured approach ensures a high level of reliability in evaluating WBC’s effectiveness for post-run recovery. Table 1: CEBM Level of Evidence Level Research Design Level 1aSystematic Reviews of Randomized Controlled Trials (RCT) Level 1bIndividual RCT with Narrow Confidence Interval Level 2aSystematic Reviews of Cohort Studies Level 2bIndividual Cohort Study and Low Quality RCT Level 3aSystematic Reviews of Case-Control Studies Level 3bIndividual Case-Control Studies Level 4Case-series and Poor Quality Cohort and Case- Control Studies Level 5Expert Opinion

Volume 6 | Issue 2 | 3 of 9J Nurs Care Repo; 2025 www.unisciencepub.com Table 2: PEDro Scale Criterium Eligibility criteria were specified Subjects were randomly allocated to groups Allocation was concealed The groups were similar at baseline regarding the most important prognostic indicators There was a blinding of subjects There was a blinding of the therapists who administered the therapy There was a blinding of assessors who measured at least one key outcome Measures of at least one key outcome were obtained by at least 85% of the subjects allocated to the group All subjects received the treatment or control condition as allocated, or, where this was not the case, data for at least one key outcome was analyzed by “intention to treat” Results of between-group statistical comparisons were reported for at least one key outcome The study provides point measures and measures of variability for at least one key outcome Exclusion Criteria Studies were excluded if they did not involve runners, utilized partial-body cryotherapy (PBC) instead of whole- body cryotherapy (WBC), or failed to assess both muscle performance and perceived muscle soreness. Included Studies This systematic review identified four relevant studies (n=4). Table 3 provides details on each study, including CEBM and PEDro scores, participant demographics, the specific WBC equipment used, and the comparison intervention. All four studies examined perceived muscle soreness and muscle function recovery as key outcome measures. Hausswirth et al. (2011) This study involved nine well-trained runners who completed three simulated trail runs over non- consecutive weeks. Each recovery session included one of three interventions: WBC, far-infrared radiation therapy, or passive recovery. WBC was administered using the Zimmer Elektromedizin unit, consisting of three chambers at -10°C, -60°C, and -110°C. Participants were exposed for three minutes in the coldest chamber after a brief acclimation period. Perceived muscle soreness was measured using the Mindeval questionnaire, while muscle function recovery was assessed through maximal voluntary knee extensor torque (Hausswirth et al., 2011). Kruger et al. (2015) Eleven endurance-trained athletes were randomly assigned to either a WBC or placebo group. The exercise protocol included a treadmill ramp-test followed by

in the coldest chamber after a brief acclimation period. Perceived muscle soreness was measured using the Mindeval questionnaire, while muscle function recovery was assessed through maximal voluntary knee extensor torque (Hausswirth et al., 2011). Kruger et al. (2015) Eleven endurance-trained athletes were randomly assigned to either a WBC or placebo group. The exercise protocol included a treadmill ramp-test followed by high-intensity interval running. Participants in the WBC group underwent three minutes of WBC, while the placebo group performed a three-minute walk in a temperate room. Muscle soreness was evaluated through a two-part questionnaire, and muscle function recovery was measured by comparing time- to-exhaustion between the first and second ramp tests. (Kruger et al., 2015). Russell et al. (2017) Fourteen male soccer players were divided into WBC and control groups. Participants performed sprint repetitions with rapid deceleration to induce muscle damage. The WBC group underwent treatment in a BOC Cryotherapy Chamber (-60°C for 30 seconds, then -135°C for two minutes), while the control group remained seated in a temperate room. Muscle soreness was assessed using a 7-point Likert scale, and muscle function recovery was evaluated through peak power output during a countermovement jump (Russell et al., 2017). Wilson et al. (2018) Thirty-one endurance-trained males were allocated to a WBC, cold-water immersion (CWI), or placebo group following a marathon. WBC participants underwent alternating exposures to -80°C to -90°C cryochambers and temperate rooms. The CWI group immersed their lower limbs in 8°C water for 10 minutes, while the placebo group rested and consumed a fruit-flavored drink mislabeled as a recovery supplement. Muscle soreness was measured using a 10-point Likert scale, and muscle function recovery was assessed via knee extensor torque, maximal voluntary contraction, and reactive strength index from a drop jump test (Wilson et al., 2018).

J Nurs Care Repo; 2025 www.unisciencepub.com Volume 6 | Issue 2 | 4 of 9 Table 3: Articles Included in this Review Article Subjects CEBMPEDroWBC Equipment Comparison Interventions Hausswirth et al. (2011)n=9 (well-trained runners) 2B 7 Zimmer Elektromedizin, Germany Far-infrared modality, passive recovery • In 3 non-adjoining weeks, 9 runners performed 3 repetitions of 48 minute simulated trail run on treadmill • Each runner tested 3 different recovery modalities in random order, all given 1 hour post, 24 hours post, and 48 hours post exercise • All outcome measures taken before, immediately after, 1 hour post, 24 hours post, and 48 hours post exercise • Perceived soreness tested with Mindeval system questionnaire; recovery of muscle function measured with knee extensor torque assessment using isokinetic ergometer Kruger et al. (2015) n=11 (endurance-trained male athletes) 2B 7 Zimmer MedizinSysteme GmbH, Ulm, Germany Placebo (3-minute walk) • Subjects randomly assigned to WBC or placebo group • Two test days separated by at least 1 week; test day started with ramp-test protocol to individual exhaustion (increasing treadmill gradient every 30 seconds until exhaustion), followed by high-intensity interval running on treadmill, followed by 1 hour of passive recovery with either 3 minutes WBC or 3 minutes walking, followed by second ramp-test protocol • PEPS and EZ Scale questionnaires given prior to first ramp-test, directly following high-intensity interval running, half- way through 1-hour rest, directly prior to second ramp-test, and directly after second ramp-test • Perceived soreness measured with PEPS and EZ scales (both questionnaires which include adjectives about perceived physical state with associated 0-5 scales); recovery of muscle function measured by differences in time-to-exhaustion between ramp tests Russell et al. (2017)n=14 (male academy soccer players) 2B 7 BOC Cryotherapy Chamber, Linde, Surrey, United Kingdom Passive recovery • Each subject participated in trials for both WBC modality and passive recovery modality, trials separated by 7 days • Subjects performed short 5 minute warm-up, followed by 2 counter-movement jump attempts, followed by 10 minute dynamic warm-up and 5 minute passive rest, followed by 15 x 30 m timed sprints (each separated by 60 second rest and each

recovery • Each subject participated in trials for both WBC modality and passive recovery modality, trials separated by 7 days • Subjects performed short 5 minute warm-up, followed by 2 counter-movement jump attempts, followed by 10 minute dynamic warm-up and 5 minute passive rest, followed by 15 x 30 m timed sprints (each separated by 60 second rest and each requiring deceleration to a standstill within a 10 m zone), followed by either WBC or passive recovery modality that starts within 20 minutes of exercise termination • Outcome measures taken pre-, immediately post-, 2 hours post, and 24 hours post-exercise • 7-point Likert scale used to measure perceived muscle soreness; recovery of muscle function measured by peak power output during countermovement jumps Wilson et al. (2018)n=31 (endurance-trained males) 2B 7 CryoClinics, London, UK Cold-water immersion, placebo (fruit-flavored drink/passive recovery) • Subjects randomly assigned into placebo (n=10), CWI (n=11), or WBC (n=11) group • Each subject completed marathon, asked to pace run as if it were competitive, allowed to consume fluid and electrolytes during race • Allocated treatment intervention began within 15 minutes of finishing race • Outcome measures taken before race, 24 hours post, and 48 hours post-race • Perceived muscle soreness measured with 11-point Likert scale during body weight squats; recovery of muscle function measured via peak knee extensor torque, maximal voluntary isometric contraction, and reactive strength index Results Perceived Muscle Soreness As summarized in Table 4, two studies demonstrated a statistically significant advantage of whole-body cryotherapy (WBC) in reducing perceived muscle soreness following exercise-induced muscle damage from running. In (Hausswirth et al., 2011) WBC significantly reduced perceived muscle pain/soreness (p < .05) within the first hour post-exercise compared to soreness levels immediately after exercise. In contrast, far-infrared radiation (FIR) only led to a reduction at the 48-hour mark, while passive recovery showed no significant effect (Hausswirth et al., 2011). Kruger et al. reported a significant improvement in perceived muscle recovery following WBC (p < .01, d = 0.95), whereas the placebo group exhibited no improvement (Krüger et al., 2015). Russell et al. (2017) found no significant reduction in

(FIR) only led to a reduction at the 48-hour mark, while passive recovery showed no significant effect (Hausswirth et al., 2011). Kruger et al. reported a significant improvement in perceived muscle recovery following WBC (p < .01, d = 0.95), whereas the placebo group exhibited no improvement (Krüger et al., 2015). Russell et al. (2017) found no significant reduction in perceived muscle soreness in either the WBC or passive recovery groups (Russell et al., 2017). Wilson et al. (2018) observed no significant difference between WBC and cold-water immersion (CWI) in reducing muscle soreness. However, WBC appeared to have a potentially beneficial effect compared to the placebo group after 48 hours (Wilson et al., 2018).

Volume 6 | Issue 2 | 5 of 9J Nurs Care Repo; 2025 www.unisciencepub.com Table 4: Perceived Muscle Soreness Article (Year)Outcome Measure WBC Control InterventionsConfidence Interval Comments Hausswirth et al. (2011) Mindeval System Pre: 0.2 +/- 0.7 Post: 60.6 +/- 20.7 Post 1 h: 31.7 +/- 23.8 Post 24 h: 33.3 +/- 26.1 Post 48 h: 39.0 +/- 24.0 (FIR) Pre: 1.6 +/- 3.2 Post: 61.9 +/- 19.0 Post 1 h: 58.3 +/- 18.4 Post 24 h: 49.3 +/- 29.1 Post 48 h: 45.2 +/- 29.1 (PAS) Pre: 0.1 +/- 0.3 Post: 55.7 +/- 18.2 Post 1 h: 44.3 +/- 23.7 Post 24 h: 53.9 +/- 25.5 Post 48 h: 58.9 +/- 19.0 95% WBC>FIR WBC>PAS The Mindeval questionnaire consists of 3 categories of questions related to pain, tiredness, and well-being. The data displayed in this table represents the results from the questions related to perceived pain, as it most closely correlates to muscle soreness. Kruger et al. (2015) PEPS and EZ Scale R1 pre : 3.3 +/- 1.1 R1 post : 2.8 +/- 1.2 Rest 30 min : 3.0 +/- 1.1 R2 pre : 3.3 +/- 1.0 R2 post : 2.3 +/- 1.0 (PBO) R1 pre : 3.3 +/- 0.5 R1 post : 2.6 +/- 1.1 Rest 30 min : 2.0 +/- 0.7 R2 pre : 2.3 +/- 1.0 R2 post : 2.0 +/- 1.1 95% WBC>PBO The PEPS and EZ scales contain questions pertaining to perceived physical state. The data displayed in this table represent the results from the questions within the category of “perceived sensation of recovery,” as it most closely correlates with muscle soreness. Russell et al. (2017) 7-point Likert Scale Pre: 1+/- 1 Post: 3 +/- 2 Post 2 h: 1 +/- 1 Post 24 h: 2 +/- 2 (CON) Pre: 1+/- 1 Post: 3 +/- 2 Post 2 h: 2 +/- 1 Post 24 h: 2 +/- 2 95% WBC=CON Wilson et al. (2018) 11-point Likert Scale B-24 h: 1 +/- 1 B-48 h: 0 +/- 1 (PL) B-24 h: 2 +/- 1 B-48 h: 1 +/- 1 (CWI) B-24 h: 2 +/- 1