Effects of endurance fitness on responses to cold water immersion

ArticleinAviation Space and Environmental Medicine 55(8):715-20 · September 1984with11 Reads
Source: PubMed
The purpose of this study was to determine if the changes in selected blood hormones and substrates, metabolic rate, and rectal temperature (Tre) in nine males after immersion in 10 degrees C water, while clad in standard flight suits, were related to the level of aerobic fitness. Fitness was evaluated by the blood lactate response to submaximal exercise. Immersion time (IT) was defined as the time required for a 1 degrees C decrease in Tre and averaged 38.5 (range: 21-62) min. Metabolic rate increased 3.4 times the resting rate. Lactate, free fatty acids, triiodothyronine and thyroxine increased by 81%, 38%, 11%, and 8%, respectively, in contrast to insulin which decreased by 32%, with all changes being statistically significant (p less than 0.05). Glucagon increased slightly but not significantly (p = 0.11) while glucose levels did not change. The IT was correlated directly with a measure of aerobic fitness, with relative body fat, and with the T3 levels postimmersion (p less than 0.05). The results suggest that the aerobic fitness level can significantly influence the cooling rate during water immersion.
    • "Kollias et al. [20] found that cold-exposed, endurance-trained subjects had a low thermogenic threshold. Conversely , others have reported that trained athletes have improved cold tolerance [15] and greater thermoregulatory sensitivity [2]. Cold acclimation may interfere with training adaptations, as it reduces sympathetic responses to the cold and therefore reduces the rates of glycogenolysis and lipolysis, as well as promoting vasoconstric- tion [17]. "
    [Show abstract] [Hide abstract] ABSTRACT: We investigated physiological responses and changes in circulating immune cells following exercise in cold and thermoneutral conditions. Participants were short track skaters (n=9) who were acclimatized to cold conditions, and inline skaters (n=10) who were not acclimatized. All skaters were young, and skating at a recreational level three days per week for at least one year. Using a cross-over design, study variables were measured during 60 min of submaximal cycling (65% [Formula: see text]O2max) in cold (ambient temperature: 5±1°C, relative humidity: 41±9%) and thermoneutral conditions (ambient temperature: 21±1°C, relative humidity: 35±5%). Heart rate, blood lactate and tympanic temperature were measured at rest, during exercise and recovery. Plasma cortisol, calprotectin and circulating blood cell numbers were measured before and after 60 min of cold or thermoneutral conditions, and during recovery from exercise. Heart rate was lower in both groups during exercise in cold versus thermoneutral conditions (P<0.05). The increase in total leukocytes during recovery was primarily due to an increase in neutrophils in both groups. The cold-acclimatized group activated neutrophils after exercise in cold exposure, whereas the non-acclimatized group activated lymphocyte and cortisol after exercise in cold exposure. Lymphocyte subsets significantly changed in both groups over time during recovery as compared to rest. Immediately after exercise in both groups, CD16+ and CD69+ cells were elevated compared to rest or before exercise in both conditions. Acclimatization to exercise in the cold does not appear to influence exercise-induced immune changes in cold conditions, with the possible exception of neutrophils, lymphocytes and cortisol concentration.
    Full-text · Article · Mar 2014
    • "However, Keatinge (1961) found that cold-immersed subjects displayed a reduced metabolic response within the fi rst 30 min of an extended exposure, following endurance training. Others have similarly found that cold-exposed, endurance-trained subjects displayed a reduced thermogenic threshold (Dressendorfer et al. 1977, Kollias et al. 1972), while other investigators have reported improved cold tolerance (Jacobs et al. 1984) and an elevated thermoregulatory sensitivity (Bittel et al. 1988). Notwithstanding these disparate outcomes, it may be argued that endurance training increases metabolic effi ciency during the early stages of cold exposure and, like some cold-adapted ethnic populations, may facilitate enhanced energy conservation during the more stressful stages of exposure. "
    Full-text · Chapter · Jan 2008 · Journal of Sports Sciences
    • "Golden and colleagues (1979) identified that submaximal and maximal shivering were positively correlated to an individual's aerobic power (V ˙ O 2max ). Similarly, Jacobs et al. (1984) identified that the time taken to achieve a 18C drop in rectal temperature when exposed to water of 108C was also related positively to aerobic fitness, as assessed by a blood lactate response to a sub-maximal workload (Fig. 2 ). No such correlation was found by Tikuisis et al. (1999) when their participants were exposed to an air temperature of 108C. "
    [Show abstract] [Hide abstract] ABSTRACT: Exercising in the cold is not an attractive option for many athletes; however, defining what represents cold is difficult and is not standard for all events. If the exercise is prolonged and undertaken at a moderate intensity, environmental temperatures around 11 degrees C can be an advantage. If the intensity is lower than this value and the individual does not generate sufficient metabolic heat to offset the effects imposed by the cold environment, then temperatures of 11 degrees C can be detrimental to performance. Similarly, when the performance involves dynamic explosive contractions, then a Cold ambient temperature can have a negative influence. Additional factors such as the exercising medium, air or water, and the anthropometric characteristics of the athlete will also make a difference to the strategies that can be adopted to offset any negative impact of a cold environment on performance. To plan for a performance in the cold requires an understanding of the mechanisms underpinning the physiological response. This review attempts to outline these mechanisms and how they can be manipulated to optimize performance.
    Full-text · Article · Nov 2004
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