In the realm of sports science and athletic recovery, cold and hot water immersions have long been hailed as practical, accessible methods to mitigate muscle soreness and hasten recovery following intense physical exertion. These hydrotherapy techniques, often championed in gyms and professional training centers alike, are believed to influence physiological parameters that might accelerate muscle healing after damage induced by strenuous exercise. However, a recent randomized controlled trial conducted by Vanessa Wellauer and her team at the University of Applied Sciences and Arts of Southern Switzerland presents compelling evidence questioning the efficacy of these popular recovery strategies specifically in women.
Published in the open-access journal PLOS One on May 7, 2025, this rigorous clinical trial sought to address a notable gap in exercise recovery research by focusing exclusively on female participants. Historically, much of the scientific inquiry into exercise-induced muscle damage (EIMD) and subsequent recovery modalities has underrepresented women, despite physiological and hormonal differences that could profoundly impact outcomes. By enrolling thirty female volunteers, the investigators designed their study to evaluate whether cold- or hot-water immersion—applied immediately following a high-intensity plyometric protocol—would accelerate recovery compared to no intervention.
The chosen exercise regimen involved five sets of 20 drop-jumps from a 0.6-meter-high box, a well-validated method to induce controlled, uniform muscle microtrauma, especially targeting knee extensor muscles. This eccentric loading is known to cause minute muscle fiber damage that triggers inflammatory processes, swelling, and soreness, which together compromise muscle performance over ensuing days. After the exercise session, each participant was randomly allocated to one of three groups: cold-water immersion (approximately 10°C), hot-water immersion (around 39°C), or a control group with no exposure to water baths. Immersions extended to the sternum level and lasted for 10 minutes immediately post-exercise and were repeated two hours later.
Physiological data collected during the recovery window revealed expected thermal and vascular responses: cold immersion resulted in transient reductions in muscle oxygen saturation levels—likely due to vasoconstriction—whereas hot immersion elevated core body temperatures consistent with vasodilation and increased metabolic rate. Non-immersed participants’ values fell between these extremes. Despite these acute physiological modulations, subsequent analyses of muscle recovery markers delivered surprising findings. Key indicators such as muscle swelling assessed via imaging, subjective muscle soreness evaluated through standardized scales, serum creatine kinase (CK) levels—a biomarker for muscle damage—and maximal voluntary isometric contraction (MVIC) strength tests showed no significant differences among the cold, hot, and control groups up to 72 hours post-exercise.
The lack of accelerated recovery in immersion groups challenges widely held assumptions and the anecdotal popularity of water immersion therapies among female athletes and fitness enthusiasts. The authors emphasize that while cold and hot water immersions differentially affect physiological parameters related to blood flow and tissue oxygenation, these effects do not necessarily translate into improved functional recovery or reduced muscle damage. This disconnect highlights the complexity of biological recovery processes, where modulation of singular physiological variables may not be sufficient to influence multifactorial outcomes like inflammation resolution, muscle repair, and neuromuscular function restoration.
An important contribution of this study lies in its exclusive focus on women, a demographic often excluded or underpowered in prior studies. The sex-specific hormonal milieu, including fluctuating estrogen and progesterone levels, alters inflammatory responses, muscle metabolism, and vascular tone, potentially rendering female responses to hydrotherapy distinct from males. Wellauer and colleagues suggest that the absence of benefits from water immersion in their cohort might reflect such sex-specific physiological nuances. Their work calls for further focused investigations probing these sex-based differences to elucidate tailored recovery interventions.
Moreover, the researchers suggest that the exercise task employed, comprising drop jumps, primarily induces eccentric damage localized to specific lower limb muscle groups and may not perfectly reflect all types of physical activities encountered in training or competitive sports. The generalizability of findings to other endurance, strength, or mixed-modal exercise types remains uncertain. Future studies could incorporate more ecologically valid exercise paradigms or real-world sports scenarios, enabling a comprehensive understanding of how hydrotherapy interventions perform across diverse athletic populations and exercise modalities.
This trial also sparks important methodological reflections regarding timing, dosage, and temperature thresholds of water immersion therapy protocols. The current study’s parameters—two 10-minute immersions at fixed temperatures shortly after exercise—may differ from other protocols reported in the literature that vary immersion duration, frequency, or temperature extremes. Such variations could influence the presence or absence of therapeutic benefits. Hence, while the study provides robust evidence against the efficacy of cold and hot water immersion as deployed in this design, these findings should not be interpreted as conclusive repudiation of hydrotherapy as a whole.
In terms of clinical and practical applications, these results urge coaches, athletes, and physiotherapists to critically evaluate the use of cold or hot water immersion in female clients and to consider alternative or adjunctive recovery strategies with more consistently proven benefits. Interventions such as active recovery, nutritional modulation, compression garments, or emerging biologically targeted therapies might hold greater promise and warrant exploration in gender-specific trials. The current findings underline the necessity for evidence-based practices tailored to the female athlete, eschewing one-size-fits-all recommendations often extrapolated from predominantly male-centric research.
Additionally, the study enriches the ongoing dialogue concerning the underlying physiological mechanisms of muscle recovery. The mismatch between observed changes in muscle oxygen saturation or core temperature and the lack of functional recovery improvements suggests that recovery is orchestrated by complex, overlapping pathways involving immune signaling, cellular repair, metabolic restoration, and neuromuscular adaptations. Future research incorporating molecular biomarkers, imaging modalities, and advanced physiological monitoring could decode these intricate interactions, ultimately facilitating the design of targeted interventions.
The neutrality of funding sources and declaration of no competing interests by the authors enhance the credibility and impartiality of this work. Supported by meticulous methodology and transparent reporting standards, Wellauer et al.’s study embodies a valuable contribution to exercise physiology literature and sets a precedent for future studies prioritizing female representation and rigorous clinical trial designs.
As the scientific community continues to grapple with optimizing post-exercise recovery, these findings serve as a critical reminder that intuitive or traditional remedies, such as water immersion therapies, require robust validation within specified populations and contexts. Athletic recovery science is evolving, emphasizing nuanced, personalized approaches, and this investigation pushes the frontier toward gender-specific evidence and mechanistic clarity.
In conclusion, the enticing prospect that cold or hot water plunges serve as expedient, non-pharmacological aids for muscle repair following intense exercise in women appears unsupported by this focused clinical trial. More extensive, diverse, and mechanistically rich investigations are essential to fully elucidate the role, if any, of hydrotherapy in female athletic recovery. Meanwhile, practitioners should integrate such insights cautiously into training regimens, balancing tradition with scientific scrutiny.
Subject of Research: People
Article Title: No acceleration of recovery from exercise-induced muscle damage after cold or hot water immersion in women: A randomised controlled trial
News Publication Date: 7-May-2025
Web References: http://dx.doi.org/10.1371/journal.pone.0322416
References: Wellauer V, Clijsen R, Bianchi G, Riggi E, Hohenauer E (2025) No acceleration of recovery from exercise-induced muscle damage after cold or hot water immersion in women: A randomised controlled trial. PLoS ONE 20(5): e0322416.
Image Credits: Gin Majka, Unsplash, CC0
Keywords: exercise-induced muscle damage, hydrotherapy, cold-water immersion, hot-water immersion, muscle recovery, female athletes, randomized controlled trial, inflammation, creatine kinase, muscle soreness, plyometric exercise, gender differences
