Effects of cold water immersion on circulating inflammatory markers at the Kona Ironman World Championship

Cold water immersion (CWI) purportedly reduces inflammation and improves muscle recovery after exercise, yet its effectiveness in specific contexts (ultraendurance) remains unclear. Thus, our aim was to study hematological profiles, systemic inflammation, and muscle damage responses to a specific post-race CWI (vs. control) during recovery after the Ironman World Championship, a culmination of ∼100 000 athletes competing in global qualifying Ironman events each year. Twenty-nine competitors were randomized into either a CWI or control (CON) group. Physiological parameters and blood samples were taken at pre-race, after intervention (POST), and 24 (+1DAY) and 48 hours (+2DAY) following the race. Muscle damage markers (plasma myoglobin, serum creatine kinase) were elevated at POST, +1DAY, and +2DAY, while inflammatory cytokines interleukin (IL)-6, IL-8, and IL-10 and total leukocyte counts were increased only at POST. CWI had no effect on these markers. Numbers of the most abundant circulating cell type, neutrophils, were elevated at POST more so in CWI (p < 0.05, vs. CON). Despite that neutrophil counts may be a sensitive marker to detect subtle effects, CWI does not affect recovery markers 24- and 48-hours post-race (vs. CON). Overall, we determined that our short CWI protocol was not sufficient to improve recovery. Novelty: Ironman World Championship event increased circulating muscle damage markers, inflammatory markers, and hematological parameters, including circulating immune cell sub-populations that recover 24-48 hours after the race. 12-min CWI post-ultraendurance event affects the absolute numbers of neutrophils acutely, post-race (vs. CON), but does not impact recovery 24- and 48-hours post-race.

Influence of cold-water immersion on recovery of elite triathletes following the ironman world championship

OBJECTIVES

Cold water immersion (CWI) has been widely used for enhancing athlete recovery though its use following an Ironman triathlon has never been examined. The purpose of this paper is to determine the influence of CWI immediately following an Ironman triathlon on markers of muscle damage, inflammation and muscle soreness.

DESIGN

Prospective cohort study.

METHODS

Thirty three (22 male, 11 female), triathletes participating in the Ironman World Championships volunteered to participate (mean±SD: age=40±11years; height=174.5±9.1cm; body mass=70±11.8kg; percent body fat=11.4±4.1%, finish time=11:03.00±01:25.08). Post race, participants were randomly assigned to a 10-min bout of 10°C CWI or no-intervention control group. Data collection occurred pre-intervention (PRE), post-intervention (POST), 16h (16POST) and 40h (40POST) following the race. Linear mixed model ANOVA with Bonferroni corrections were performed to examine group by time differences for delayed onset muscle soreness (DOMS), hydration indices, myoglobin, creatine kinase (CK), cortisol, C-reactive protein (CRP), IL-6 and percent body mass loss (%BML). Pearson's bivariate correlations were used for comparisons with finishing time. Alpha level was set a priori at 0.05.

RESULTS

No significant group by time interactions occurred. Significant differences occurred for POST BML (-1.7±0.9kg) vs. 16POST, and 40POST BML (0.9±1.4, -0.1±1.2kg, respectively; p<0.001). Compared to PRE, myoglobin, CRP and CK remained significantly elevated at 40POST. Cortisol returned to PRE values by 16POST and IL-6 returned to PRE values by 40POST.

CONCLUSION

A single bout of CWI did not provide any physiological benefit during recovery from a triathlon within 40h post race. Effect of CWI beyond this time is unknown.