Details

Autor(en) / Beteiligte

• Chinevere, Troy D.
• Cadarette, Bruce S.
• Goodman, Daniel A.
• Ely, Brett R.
• Cheuvront, Samuel N.
• Sawka, Michael N.

Titel

Efficacy of body ventilation system for reducing strain in warm and hot climates

Ist Teil von

• European journal of applied physiology, 2008-06, Vol.103 (3), p.307-314

Ort / Verlag

Berlin/Heidelberg: Springer-Verlag

Erscheinungsjahr

2008

Quelle

MEDLINE

Beschreibungen/Notizen

• This study determined whether a torso-vest forced ambient air body ventilation system (BVS) reduced physiological strain during exercise-heat stress. Seven heat-acclimated volunteers attempted nine, 2-h treadmill walks at 200 W m −2 in three environments, −40°C, 20% rh (HD), 35°C, 75% rh (HW), and 30°C, 50% rh, (WW) wearing the Army Combat Uniform, interceptor body armor (IBA) and Kevlar helmet. Three trials in each environment were BVS turned on (BVS On ), BVS turned off (BVS Off ), and no BVS (IBA). In HD, BVS On significantly lowered core temperature ( T re ), heart rate (HR), mean skin temperature ( T sk ), mean torso skin temperature ( T torso ), thermal sensation (TS), heat storage ( S ), and physiological strain index (PSI), versus BVS Off and IBA ( P  < 0.05). For HW ( n  = 6), analyses were possible only through 60 min. Exercise tolerance time (min) during HW was significantly longer for BVS On (116 ± 10 min) versus BVS Off (95 ± 22 min) and IBA (96 ± 18 min) ( P  < 0.05). During HW, BVS On lowered HR at 60 min versus IBA, T sk from 30 to 60 min versus BVS Off and IBA, and PSI from 45 to 60 min versus BVS Off and at 60 min versus IBA ( P  < 0.05). BVS On changes in T re and HR were lower in HD and HW. During WW, BVS On significantly lowered HR, T sk , and T torso versus BVS Off and IBA ( P  < 0.05) during late exercise. Sweating rates were significantly lower for BVS On versus BVS Off and IBA in both HD and WW ( P  < 0.05), but not HW. These results indicate that BVS On reduces physiological strain in all three environments by a similar amount; however, in hot-dry conditions the BVS Off increases physiological strain.