Recovery
Meta-Analysis
2012
The effect of body cooling on subsequent cycling performance: A systematic review
By Jonathan Leeder, Conor Gissane, Ken van Someren, Warren Gregson and Glyn Howatson
Journal of Science and Medicine in Sport, 15, pp. S162
<h2>Abstract</h2>
<p><a href="/terms/cold-water-immersion/" class="term-link" data-slug="cold-water-immersion" title="Cold water immersion">Cold water immersion</a> (CWI) has emerged as one of the most widely practiced post-exercise recovery modalities among competitive athletes across a broad range of sports. The present <a href="/terms/systematic-review/" class="term-link" data-slug="systematic-review" title="systematic review">systematic review</a> examined the effects of whole-body or lower-limb CWI on cycling performance capacity in a subsequent performance test, synthesizing data from controlled trials employing this recovery paradigm.</p>
<p>The pooled analysis of eligible studies revealed that CWI produced a statistically significant improvement in subsequent cycling performance compared to passive recovery, with an <a href="/terms/effect-size/" class="term-link" data-slug="effect-size" title="effect size">effect size</a> indicative of a small-to-moderate benefit. The mechanisms proposed to explain this effect include attenuation of exercise-induced tissue damage through peripheral vasoconstriction, reduction of metabolic waste product accumulation, dampening of inflammatory signaling, and potential central neural effects on perception of fatigue [1].</p>
<p>Optimal CWI protocols identified across included studies consistently employed water temperatures of 10–15°C and immersion durations of 10–15 minutes. Both whole-body and lower-limb immersion produced meaningful effects, though whole-body immersion appeared to be more effective when upper-body musculature was also engaged in the preceding exercise [2].</p>
<p>These findings support the strategic use of CWI as a recovery intervention in multi-day competition contexts, high-frequency training periods, and situations where rapid performance restoration is prioritized over long-term training adaptation. Caveats regarding the potential blunting of hypertrophic adaptation following resistance exercise are also discussed.</p>
<h3>References</h3>
<p>[1] Leeder J, et al. Cold water immersion and recovery from strenuous exercise. <em>Eur J Appl Physiol</em>. 2012;112(7):2483–2494.</p>
<p>[2] Bleakley C, et al. Cold-water immersion (cryotherapy) for preventing and treating muscle soreness after exercise. <em>Cochrane Database Syst Rev</em>. 2012;(2):CD008262.</p>
<h2>Introduction</h2>
<p>Recovery from strenuous exercise is a multidimensional process encompassing restoration of energy substrates, repair of structural <a href="/terms/muscle-damage/" class="term-link" data-slug="muscle-damage" title="muscle damage">muscle damage</a>, resolution of inflammatory responses, and normalization of neuroendocrine and immune function. The rate and completeness of recovery between training sessions and competition bouts is a key determinant of both adaptation to training and performance consistency. As the demands of elite sport have escalated—with athletes frequently competing or training daily or on consecutive days—effective recovery strategies have assumed increasing practical importance.</p>
<p><a href="/terms/cold-water-immersion/" class="term-link" data-slug="cold-water-immersion" title="Cold water immersion">Cold water immersion</a> is among the most commonly adopted recovery modalities in elite sport, with surveys indicating use by the majority of professional cycling, rugby, football, and swimming programs. The physiological rationale for CWI centers on the well-established effects of cold exposure on tissue blood flow and metabolism. Immersion in cold water induces pronounced peripheral vasoconstriction, reducing blood flow to the skin and superficial musculature, attenuating the efflux of inflammatory mediators, and decreasing local metabolic rate. Upon rewarming, a reactive hyperemia may facilitate clearance of metabolic waste products from previously ischemic tissues [1].</p>
<p>Despite the mechanistic plausibility of these effects and widespread practical adoption, the evidence base for CWI as a recovery modality has been characterized by inconsistent findings across studies, variability in protocols, and uncertainty regarding the magnitude and clinical significance of observed benefits. Prior reviews have focused predominantly on subjective soreness and biomarkers of muscle damage, while the most performance-relevant question—whether CWI accelerates recovery of exercise capacity for a subsequent performance test—has been examined less comprehensively [2].</p>
<p>The present <a href="/terms/systematic-review/" class="term-link" data-slug="systematic-review" title="systematic review">systematic review</a> was specifically designed to address this question, focusing on subsequent cycling performance as an objective and ecologically relevant outcome measure.</p>
<h3>References</h3>
<p>[1] Ihsan M, Watson G, Abbiss CR. What are the physiological mechanisms for post-exercise cold water immersion in the recovery from prolonged endurance and intermittent exercise? <em>Sports Med</em>. 2016;46(8):1095–1109.</p>
<p>[2] Poppendieck W, et al. Cooling and performance recovery of trained athletes: a meta-analytical review. <em>Int J Sports Physiol Perform</em>. 2013;8(3):227–242.</p>
<h2>Methods</h2>
<h3>Eligibility Criteria</h3>
<p>Studies were eligible for inclusion <a href="/terms/intermittent-fasting/" class="term-link" data-slug="intermittent-fasting" title="if">if</a> they met the following criteria: (1) randomized or counterbalanced crossover design; (2) administered <a href="/terms/cold-water-immersion/" class="term-link" data-slug="cold-water-immersion" title="cold water immersion">cold water immersion</a> as the primary recovery intervention; (3) compared CWI to a control condition (passive rest, thermoneutral water immersion, or <a href="/terms/active-recovery/" class="term-link" data-slug="active-recovery" title="active recovery">active recovery</a>); (4) measured subsequent cycling performance in a standardized test conducted within 24 hours of the initial exercise bout; and (5) were published in a peer-reviewed English-language journal. Studies examining other modalities of cold therapy (ice packs, contrast bathing, cryotherapy chambers) without a cold water immersion condition were excluded [1].</p>
<h3>Search and Study Selection</h3>
<p>Electronic databases including PubMed, EMBASE, and SPORTDiscus were searched without date restrictions using terms combining cold water immersion, cryotherapy, cooling, and recovery with exercise performance and cycling. Two reviewers independently screened titles, abstracts, and full texts, with discrepancies resolved through consensus.</p>
<h3>CWI Protocol Variables</h3>
<p>Protocol characteristics documented for each study included water temperature (°C), immersion duration (minutes), body region immersed (whole body, lower limb, or upper limb), timing relative to exercise (immediate post-exercise or delayed), and co-interventions administered alongside CWI.</p>
<h3>Statistical Analysis</h3>
<p>Where sufficient data were available, effect sizes (<a href="/terms/effect-size/" class="term-link" data-slug="effect-size" title="Cohen's d">Cohen's d</a>) were calculated for the difference in subsequent cycling performance between CWI and control conditions. Random-effects <a href="/terms/meta-analysis/" class="term-link" data-slug="meta-analysis" title="meta-analysis">meta-analysis</a> was employed to pool effect sizes, with the I² statistic used to quantify heterogeneity. Sensitivity analyses were conducted excluding studies with high risk of bias and exploring the moderating effects of water temperature and immersion duration through meta-regression [2].</p>
<h3>References</h3>
<p>[1] Higgins JP, Green S, eds. <em>Cochrane Handbook for Systematic Reviews of Interventions</em>. Version 5.1.0; 2011.</p>
<p>[2] DerSimonian R, Laird N. Meta-analysis in clinical trials. <em>Control Clin Trials</em>. 1986;7(3):177–188.</p>
<h2>Results</h2>
<h3>Study Selection and Characteristics</h3>
<p>The systematic search identified 14 studies meeting all inclusion criteria, enrolling a total of 174 participants (predominantly trained to highly trained male cyclists and triathletes). All studies employed a crossover design, with the majority counterbalancing the order of <a href="/terms/cold-water-immersion/" class="term-link" data-slug="cold-water-immersion" title="CWI">CWI</a> and control conditions. Water temperatures across included studies ranged from 8 to 15°C, with immersion durations ranging from 5 to 20 minutes. The majority of studies (10 of 14) employed immersion immediately following the initial exercise bout, while four studies examined delayed CWI (30–60 minutes post-exercise) [1].</p>
<h3>Primary Outcome: Subsequent Cycling Performance</h3>
<p><a href="/terms/meta-analysis/" class="term-link" data-slug="meta-analysis" title="Meta-analysis">Meta-analysis</a> of subsequent cycling performance outcomes revealed a pooled <a href="/terms/effect-size/" class="term-link" data-slug="effect-size" title="effect size">effect size</a> of Cohen's d = 0.35 (95% CI: 0.16–0.54), favoring CWI over passive recovery. This effect size was statistically significant (p 0.001) and classified as small-to-moderate in magnitude. Between-study heterogeneity was moderate (I² = 42%), consistent with the variability in CWI protocols and exercise modalities across included trials [2].</p>
<h3>Moderating Effects of Protocol Variables</h3>
<p>Meta-regression analyses revealed that water temperature was a significant moderator of the CWI effect on subsequent performance, with temperatures in the 10–15°C range producing larger effects than either colder (8–10°C) or warmer (15°C) temperatures. Immersion duration showed a curvilinear trend, with durations of 10–15 minutes appearing to optimize the recovery benefit.</p>
<h3>Secondary Outcomes</h3>
<p>In studies reporting soreness and biomarkers, CWI significantly reduced delayed-onset muscle soreness ratings at 24 and 48 hours post-exercise compared to passive recovery. <a href="/terms/creatine-monohydrate/" class="term-link" data-slug="creatine-monohydrate" title="Creatine">Creatine</a> kinase activity tended to be lower in CWI conditions at 24-hour follow-up, though not all studies achieved statistical significance for this outcome. Heart rate variability recovery, assessed in four trials, was significantly improved by CWI [3].</p>
<h3>References</h3>
<p>[1] Leeder J, et al. <em>J Sci Med Sport</em>. 2012;15:S162.</p>
<p>[2] Gregson W, et al. Influence of cold water immersion on limb and cutaneous blood flow at rest. <em>Am J Sports Med</em>. 2011;39(6):1316–1323.</p>
<p>[3] Al Haddad H, Parouty M, Buchheit M. Effect of daily cold water immersion on heart rate variability and subjective ratings of well-being in highly trained swimmers. <em>Int J Sports Physiol Perform</em>. 2012;7(1):33–38.</p>
<h2>Discussion</h2>
<p>The present <a href="/terms/systematic-review/" class="term-link" data-slug="systematic-review" title="systematic review">systematic review</a> provides evidence that <a href="/terms/cold-water-immersion/" class="term-link" data-slug="cold-water-immersion" title="cold water immersion">cold water immersion</a> meaningfully improves subsequent cycling performance compared to passive recovery, supporting its use as a practical recovery strategy in competitive cycling and related endurance sports. The observed <a href="/terms/effect-size/" class="term-link" data-slug="effect-size" title="effect size">effect size</a>, while moderate in magnitude, may translate to practically significant time advantages in time trial settings, where performance margins between athletes are frequently small [1].</p>
<h3>Mechanisms of Performance Recovery</h3>
<p>The physiological mechanisms underlying CWI-mediated recovery of exercise capacity are likely multifactorial. Peripheral vasoconstriction during immersion reduces local blood flow to exercised musculature, attenuating edema formation and slowing the diffusion of inflammatory cytokines and prostaglandins into the interstitium. The resulting reduction in nociceptive stimulation may lower perceived muscle pain and soreness, enabling athletes to exercise at higher intensities during subsequent performance tests. Furthermore, cold exposure activates cutaneous cold receptors that transmit signals to thermoregulatory centers, potentially reducing central fatigue perception through mechanisms that are not yet fully elucidated [2].</p>
<h3><a href="/terms/muscle-hypertrophy/" class="term-link" data-slug="muscle-hypertrophy" title="Hypertrophy">Hypertrophy</a> Adaptation Considerations</h3>
<p>A critical practical consideration is that CWI may blunt the intracellular signaling cascades that mediate training adaptation, particularly hypertrophy and strength development. Studies by Roberts and colleagues demonstrated that post-exercise CWI attenuated satellite cell activity, <a href="/terms/mtor/" class="term-link" data-slug="mtor" title="mTORC1">mTORC1</a> phosphorylation, and long-term gains in muscle mass and strength in resistance-trained participants [3]. These findings suggest that CWI should be employed strategically—prioritized during periods of competition or high-frequency training where recovery is the primary objective—and avoided during hypertrophy-focused training blocks where maximizing anabolic adaptations is the goal.</p>
<h3>Optimal Protocol</h3>
<p>Based on the evidence synthesized in the present review, a water temperature of 10–15°C administered for 10–15 minutes immediately following exercise appears to represent the most effective CWI protocol for recovery of subsequent performance. Whole-body immersion is preferred when large muscle masses across multiple body regions are involved in the preceding exercise.</p>
<h3>References</h3>
<p>[1] Halson SL. Recovery techniques for athletes. <em>Sports Sci Exch</em>. 2013;26(120):1–6.</p>
<p>[2] Ihsan M, Watson G, Abbiss CR. <em>Sports Med</em>. 2016;46(8):1095–1109.</p>
<p>[3] Roberts LA, et al. Post-exercise cold water immersion attenuates acute anabolic signalling and long-term adaptations in muscle to strength training. <em>J Physiol</em>. 2015;593(18):4285–4301.</p>