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

Abstract

Cold water immersion (CWI) purportedly reduces inflammation and improves muscle recovery post 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 CWI or control (CON) group. Physiological parameters and blood samples were taken pre race (BASE), 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 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 determine 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.

The Influence of Ambient Temperature Changes on the Indicators of Inflammation and Oxidative Damage in Blood after Submaximal Exercise

“…In the case of IL-8, it was noticed that the concentration of this cytokine after CWI-REST was statistically significantly lower than after RT-REST. Contrary to the results obtained in this study, Bartley et al [ 59 ] observed an increase in the concentration of IL-8 after a 12-min CWI in competitors participating in the world triathlon championships. This pro-inflammatory cytokine is released in the early phase of the inflammatory response [ 68 ].…”

“…A similar direction of changes in the concentration of IL-10 in the blood serum was observed in novices. These results are consistent with the findings of Bartley et al [ 59 ], who showed an increase in the concentration of IL-10 after a 12-min CWI in competitors participating in the world triathlon championships. The results obtained in this study seem to confirm the positive effect of a single CWI as a factor regulating the local inflammation caused by exercise.…”

Metabolic and immune/inflammatory alterations induced by a triathlon under extreme conditions

“…These observations are in agreement with other studies in which, soon after high-intensity training sessions and/or a strenuous and prolonged exercise session, there was a significant increase of neutrophils (the main granulocytes cells in the blood) in opposite to a decrease of the lymphocytes accounts (Walsh et al, 2011;Morgado et al, 2016). In an interesting way, these altered number of granulocytes and lymphocytes at IM time point could impact our findings at 12 h after the competitions, in which the number of leucocytes was not completely returned to baseline values, as similarly reported in other studies (Lippi et al, 2010;Bartley et al, 2021).…”

Athlete, coach and practitioner knowledge and perceptions of post-exercise cold-water immersion for recovery: a qualitative and quantitative exploration

“…Belief stems from positive reductions in secondary cell injury and/or reducing inflammation following injury in animal models [59]. However, whilst some research shows post-exercise CWI might positively influence some markers of inflammation post-exercise [60,61], there remains a substantial contrasting volume of research showing a neutral effect, whereby CWI has no influence in moderating the post-exercise inflammatory response [15,[62][63][64][65][66]. This is supported further by cellular and molecular investigations [58].…”

“…The most reported mechanisms associated with benefits of CWI were cardiovascular alterations in blood flow and constriction of blood vessels. To date, a significant amount of work has demonstrated reduced limb blood flow, or reduced blood volume, across the exercised muscle following CWI [47,[53][54][55][56][57][58][59][60][61][62][63][64][65][66][67][68][69][70]. However, more recent data [71] employing positron emission tomography (PET) with an oxygen-15-labelled water radiotracer ([ 15 O]H 2 O) suggests that application of noxious water temperatures (< 8 °C) may actually result in less pronounced reductions in muscle perfusion compared with less noxious (15 °C) immersion (under resting conditions).…”