A Mixed-Method Approach of Pre-Cooling Enhances High-Intensity Running Performance in the Heat

Abstract

We investigated whether single or combined methods of pre-cooling could affect high-intensity exercise performance in a hot environment. Seven male athletes were subjected to four experimental conditions for 30 min in a randomised order. The four experimental conditions were: 1) wearing a vest cooled to a temperature of 4 ℃ (Vest), 2) consuming a beverage cooled to a temperature of 4 ℃ (Beverage), 3) simultaneous usage of vest and consumption of beverage (Mix), and 4) the control trial without pre-cooling (CON). Following those experimental conditions, they exercised at a speed of 80% VO2max until exhaustion in the heat (38.1 ± 0.6 ℃, 55.3 ± 0.3% RH). Heart rate (HR), rectal temperature (Tcore), skin temperature (Tskin), sweat loss (SL), urine specific gravity (USG), levels of sodium (Na+) and potassium (K+), rating of perceived exertion (RPE), thermal sensation (TS), and levels of blood lactic acid ([Bla]) were monitored. Performance was improved using the mixed pre-cooling strategy (648.43 ± 77.53 s, p = 0.016) compared to CON (509.14 ± 54.57 s). Tcore after pre-cooling was not different (Mix: 37.01 ± 0.27 ℃, Vest: 37.19 ± 0.33 ℃, Beverage: 37.03 ± 0.35 ℃) in all cooling conditions compared to those of CON (37.31 ±0.29 ℃). A similar Tcore values was achieved at exhaustion in all trials (from 38.10 ℃ to 39.00 ℃). No difference in the level of USG was observed between the conditions. Our findings suggest that pre-cooling with a combination of cold vest usage and cold fluid intake can improve performance in the heat.

Topical Analgesic Containing Methyl Salicylate and L-Menthol Accelerates Heat Loss During Skin Cooling for Exercise-Induced Hyperthermia

“…Individuals who perform intense physical activity in a hot environment, including those who exercise in summer heat, members of the military, and firefighters, are at increased risk for hyperthermia ( Douma et al, 2020 ). To alleviate a hyperthermic state, extensive prior research has focused various cooling strategies including cold water immersion (CWI) ( Armstrong et al, 1996 ; Proulx et al, 2003 ; Luhring et al, 2016 ), topical body cooling ( Scheadler et al, 2013 ; Adams et al, 2016 ; Cuttell et al, 2016 ), cooling garments ( Eijsvogels et al, 2014 ; Abdallah et al, 2015 ; Xu et al, 2021 ), or ice-sheets ( Butts et al, 2017 ), etc. Among those, CWI is considered the current gold standard for treating hyperthermia by most professionals and organizations ( Casa et al, 2007 ; Zhang et al, 2015 ; Nye et al, 2016 ).…”

Modulation of Leukocyte Subsets Mobilization in Response to Exercise by Water Immersion Recovery

“…These effects are influenced by water temperature. Cold water immersion, for example, decreases skin, core, and muscle temperatures ( Peiffer et al, 2009 , 2010 ; Gregson et al, 2011 ), which can account for improved performance in long duration tests, especially in warm/hot temperatures, due to a pre-cooling effect ( Quod, Martin and Laursen, 2006 ; Xu et al, 2021 ). Cold water immersion is also associated with vasoconstriction, which further increases central blood flow ( Choo et al, 2018 ) and promotes a relative decrease in the local blood flow ( Fiscus, Kaminski and Powers, 2005 ; Vaile et al, 2011 ; Seeley, Giersch and Charkoudian, 2021 ).…”

Performance effects of internal pre- and per-cooling across different exercise and environmental conditions: A systematic review

“…The average VO 2 max of the participants was 56.0 mL⋅kg –1 ⋅min –1 (ranging from 46.2 ( 103 ) to 67.2 mL⋅kg –1 ⋅min –1 ( 109 )). Seventeen studies included physically active participants ( 93 , 94 , 97 , 101 , 104 , 105 , 107 , 110 – 118 ), twenty-one included recreational athletes ( 95 , 96 , 98 – 100 , 106 , 108 , 119 – 131 ), and five involved professional athletes ( 102 , 109 , 132 – 135 ).…”

“…VO 2 max speed cycling protocol (131), neither mean power output or total work done in a 60-min fixed 15-RPE (121) and 60-min fixed 55%VO 2 peak cycling protocols (115). Finally, completion time was not significantly lower while pre-cooling with ice or cold beverages in a 30-km (123), 800-kJ (98) and 30min fixed 75% of peak power output (125) cycling time trials, not either in a 5-km running time trial protocol (129).…”

“…This can happen when the environmental temperature is much higher than skin temperature, and also when T core decreases very fast at the beginning of the exercise (93). On the other hand, cooling strategies may provide the most gains in physical performance in stressful environmental conditions (higher temperatures and humidity levels and/or longer duration and greater intensity exercises) (95), that were not observed in some of the included studies (97,99,122,127,131,132,139). As increases in core temperature are proportional to exercise intensity (166), it is easier to avoid an increase in heat strain in exercises protocols whose intensity is not great, or at least is interspersed with moments of lower intensity recovery periods (intermittent efforts), minimizing the benefits of administering an ice or cold beverage.…”