RESEARCH STUDY FROM 2009. HEAT & ATHLETES.
THE EFFECTS OF VARIOUS COOLING METHODS IN REDUCING CORE BODY TEMPERATURE DURING RECOVERY FROM EXERCISE IN THE HEAT.
THE EFFECT OF VARIOUS COOLING METHODS IN REDUCING CORE BODY TEMPERATURE DURING RECOVERY FROM EXERCISE IN THE HEAT.
DEMARTINI JK, RANALLI GF, CASA DJ, LOPEZ RM, GANIO MS, MCDERMOTT BP, STEARNS RL, ARMSTRONG LE, MARESH CM: UNIVERSITY OF CONNECTICUT, STORRS, CT
CONTEXT: HYPERTHERMIA, WHICH CAN BECOME DANGEROUS AND/OR INFLUENCE PERFORMANCE, IS COMMON IN THE ATHLETIC POPULATION AND IN A VARIETY OF ENVIRONMENTS. THIS STUDY WILL PROVIDE SOME DIRECTION FOR CERTIFIED ATHLETIC TRAINERS AND OTHER MEDICAL PERSONNEL AS TO WHAT COOLING METHODS HAVE THE BEST EFFICACY TO COOL HYPER THERMIC ATHLETES DURING A BRIEF RECOVERY PERIOD.
OBJECTIVE: THE PURPOSE OF THIS STUDY WAS TO EVALUATE AND COMPARE THE EFFECTIVENESS OF DIFFERENT COOLING METHODS IN LOWERING THE CORE BODY TEMPERATURE OF INDIVIDUALS FOLLOWING EXERCISE IN THE HEAT.
DESIGN: RANDOMIZED CROSSOVER DESIGN.
SETTING: OUTDOOR SPORTS COMPLEX IN WARM ENVIRONMENT (MEAN ± SD: WBGT:26.64 ± 4.71°C).
PATIENTS OR OTHER PARTICIPANTS: SIXTEEN MALES (N=9) AND FEMALES (N=7) (24 ± 6 YR, 182 ± 7 CM, 74.03 ± 9.17 KG, 17.08 ± 6.23% BODY FAT).
INTERVENTIONS: SUBJECTS EXERCISED FOR TWO TO THREE ONE-HOUR SESSIONS OVER FOUR DAYS. AFTER EACH EXERCISE BOUT, SUBJECTS WERE COOLED FOR 10 MINUTES IN A SHADED PAVILION (WBGT:22.37 ± 4.55OC) BY ONE OF 9 COOLING MODALITIES INCLUDING COLD WATER IMMERSION (CWI), SHADE, PORT-A-COOLÂ (FAN), EMERGENCY COLD CONTAINMENT SYSTEMÂ (ECCS), REHAB HOODÂ (HOOD), NIKE ICE VESTÂ (NIV), GAME READY ACTIVE COOLING VESTÂ (GRV), ICE BUCKETS, AND ICE TOWELS. THESE COOLING RATES WERE COMPARED TO SUN (CONTROL).
MAIN OUTCOME MEASURES: RECTAL TEMPERATURE (TRE), HEART RATE (HR), THIRST SENSATION, THERMAL SENSATION, AND A MODIFIED ENVIRONMENTAL SYMPTOMS QUESTIONNAIRE (ESQ). RESULTS: THE AVERAGE TRE FOLLOWING EXERCISE (PRE-COOLING) ACROSS ALL TRIALS WAS 38.73°C ± .12. AFTER 10 MINUTES OF COOLING CWI (-.65 ± .29°C), ICE BUCKETS (-.74 ± .34°C), AND ECCS (-.68 ± .24°C) HAD SIGNIFICANTLY (P<0.006) GREATER DECREASE IN TRE COMPARED TO SUN (-.42 ± .15°C). HR AT THE TEN-MINUTE MARK WAS SIGNIFICANTLY (P<0.006) LOWER FOR CWI (82 ± 15 BPM), FAN (88 ± 12 BPM), ECCS (87 ± 14 BPM), AND ICE TOWELS (84 ± 15 BPM) AS COMPARED TO SUN (101 ± 15 BPM). THERMAL SENSATION SCORES BETWEEN MODALITIES WERE ALL SIGNIFICANTLY (P<0.006) LOWER (CWI: 1.7 ± .6; FAN: 3.2 ± .8; ECCS: 4.6 ± .7; HOOD: 4.6 ± .6; NIV: 4.5 ± 1; GRV: 4.0 ± .5; ICE BUCKETS: 4.0 ± 1; ICE TOWELS: 3.0 ± 1) WHEN COMPARED TO SUN (5.5 ± .5) EXCEPT FOR SHADE (5.0 ± 0.8). THERE WERE NO SIGNIFICANT DIFFERENCES (P>0.006) IN THIRST SCORES BETWEEN ALL MODALITIES WHEN COMPARED TO SUN. ESQ SCORES WERE SIGNIFICANTLY (P<0.006) LOWER FOR CWI (1 ± 6), FAN (4 ± 5), AND ICE TOWELS (3 ± 8) WHEN COMPARED TO SUN (13 ± 12).
CONCLUSIONS: OUR FINDINGS INDICATE WHEN ATHLETES ARE EXPERIENCING MILD HYPERTHERMIA FOLLOWING INTENSE EXERCISE IN THE HEAT THAT CWI, ICE BUCKETS, AND ECCS OFFER SUPERIOR COOLING RATES (AS COMPARED TO REST IN THE SUN) DURING A BRIEF PERIOD.