title: Effect of air-filled vest on exercise-heat strain when wearing ballistic protection.
abstract: OBJECTIVE
  The purpose was to determine if an air-filled vest worn under ballistic protection reduces physiological strain during exercise in the heat either while wearing a tactical military (TM) protective vest or a law enforcement (LE) concealable vest.
  
  
  METHODS
  Sixteen men (24.5±3.9 years; 179.5±5.6 cm; 84.6±12.3kg) performed either two or four trials of treadmill walking (1.34 m s(-1); 2% grade) over 120 min in a hot, dry environment (37°C, 30% relative humidity, wind speed 3.5 m s(-1)). Participants completed trials wearing a TM or LE, with either the air-filled vest (TMa; LEa) or no vest (TMc; LEc) in random order. During trials, participants wore Army Combat Uniform pants. Physiological variables measured every 5min included gastrointestinal temperature (T GI), mean skin temperature (T sk), and heart rate (HR). Sweat rate (SR) was calculated based on fluid intake and body mass measures.
  
  
  RESULTS
  In the tactical trial (TMa versus TMc), no differences in final T GI (38.2±0.4 versus 38.3±0.4°C), T sk (35.0±0.9 versus 35.0±1.0°C), HR (142±19 versus 143±23 bpm) existed (P>0.05). In the LE trials (LEa versus LEc), no differences in final T GI (38.0±0.4 versus 38.1±0.3°C), T sk (35.3±1.1 versus 35.6±0.9°C), HR (132±20 versus 135±20 bpm) existed (P>0.05). Despite slightly higher SR, there was no statistical difference in TM (1.15±1.13 versus 1.54±0.46 l h(-1); P=0.10) or in LE (1.39±0.52 versus 1.37±0.18 l h(-1); P=0.35) during trials.
  
  
  CONCLUSIONS
  When participants exercised with a TM or LE while wearing the air-filled vest, there were no thermoregulatory and physiological differences compared to control trials. In our testing conditions, the air-filled device had little effect on physiological responses during prolonged mild exercise in the heat.
authors.affiliation: Human Performance Laboratory, Department of Health, Human Performance, and Recreation, University of Arkansas, HPER 321, 155 Stadium Drive, Fayetteville, AR 72701, USA.
authors.forename: J D
authors.initials: JD
authors.lastname: Adams
authors.affiliation: Human Performance Laboratory, Department of Health, Human Performance, and Recreation, University of Arkansas, HPER 321, 155 Stadium Drive, Fayetteville, AR 72701, USA brendonm@uark.edu.
authors.forename: Brendon P
authors.initials: BP
authors.lastname: McDermott
authors.affiliation: Human Performance Laboratory, Department of Health, Human Performance, and Recreation, University of Arkansas, HPER 321, 155 Stadium Drive, Fayetteville, AR 72701, USA.
authors.forename: Christian B
authors.initials: CB
authors.lastname: Ridings
authors.affiliation: Human Performance Laboratory, Department of Health, Human Performance, and Recreation, University of Arkansas, HPER 321, 155 Stadium Drive, Fayetteville, AR 72701, USA.
authors.forename: Lacey L
authors.initials: LL
authors.lastname: Mainer
authors.affiliation: Human Performance Laboratory, Department of Health, Human Performance, and Recreation, University of Arkansas, HPER 321, 155 Stadium Drive, Fayetteville, AR 72701, USA.
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Ganio
authors.affiliation: Human Performance Laboratory, Department of Health, Human Performance, and Recreation, University of Arkansas, HPER 321, 155 Stadium Drive, Fayetteville, AR 72701, USA.
authors.forename: Stavros A
authors.initials: SA
authors.lastname: Kavouras
mesh_terms: D000328:Adult; D015444:Exercise / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology; D018882:Heat Stress Disorders / Q000517:prevention & control*; D006801:Humans; D008297:Male; D008889:Military Personnel; D011481:Protective Clothing / Q000009:adverse effects*; D012881:Skin Temperature / Q000502:physiology; D013546:Sweating / Q000502:physiology; D055815:Young Adult
keywords: law enforcement; military; thermoregulation