title: Cooling vest worn during active warm-up improves 5-km run performance in the heat.
abstract: We investigated whether a cooling vest worn during an active warm-up enhances 5-km run time in the heat. Seventeen competitive runners (9 men, maximal oxygen uptake = 66.7 +/- 5.9 ml x kg(-1) x min(-1); 8 women, maximal oxygen uptake = 58.0 +/- 3.2 ml x kg(-1) x min(-1)) completed two simulated 5-km runs on a treadmill after a 38-min active warm-up during which they wore either a T-shirt (C) or a vest filled with ice (V) in a hot, humid environment (32 degrees C, 50% relative humidity). Wearing the cooling vest during warm-up significantly (P < 0.05) blunted increases in body temperature, heart rate (HR), and perception of thermal discomfort during warm-up compared with control. At the start of the 5-km run, esophageal, rectal, mean skin, and mean body temperatures averaged 0.3, 0.2, 1.8, and 0.4 degrees C lower; HR averaged 11 beats/min lower; and perception of thermal discomfort (5-point scale) averaged 0.6 point lower in V than C. Most of these differences were eliminated during the first 3.2 km of the run, and these variables were not different at the end. The 5-km run time was significantly lower (P < 0.05) by 13 s in V than C, with a faster pace most evident during the last two-thirds of the run. We conclude that a cooling vest worn during active warm-up by track athletes enhances 5-km run performance in the heat. Reduced thermal and cardiovascular strain and perception of thermal discomfort in the early portion of the run appear to permit a faster pace later in the run.
authors.affiliation: Department of Excercise Science, University of Georgia, Athens, Georgia 30602-6554, USA. sarngrim@khi.is
authors.forename: Sigurbjörn A
authors.initials: SA
authors.lastname: Arngrïmsson
authors.forename: Darby S
authors.initials: DS
authors.lastname: Petitt
authors.forename: Matthew G
authors.initials: MG
authors.lastname: Stueck
authors.forename: Dennis K
authors.initials: DK
authors.lastname: Jorgensen
authors.forename: Kirk J
authors.initials: KJ
authors.lastname: Cureton
mesh_terms: D001831:Body Temperature; D005260:Female; D006339:Heart Rate; D006358:Hot Temperature; D006801:Humans; D007053:Ice; D008297:Male; D011481:Protective Clothing; D012420:Running / Q000502:physiology*; D012881:Skin Temperature; D013647:Task Performance and Analysis; D013697:Thermosensing; D013997:Time Factors
chemical_list: D007053:Ice