Comparison of human stress reactions during parachuting training when dressed two kinds of protection system of paratroops

Objective To compare the human stress reactions during parachuting training when dressed two kinds of protective system of paratroops. Methods Twenty paratroopers were served as subjects. They were randomly divided into two groups (n= 10) and respectively dressed A and B types of protective systems of paratroops for parachuting training and performing tactical exercise for approximate 30 rain after landing. The G load, heart rate and temperature of chest skin were recorded continuously during the parachuting and tactical exercise after landing. The urine samples of baseline, before parachuting and after landing were analyzed. The subjective fatigue feelings at different stages were evaluated by using Rating of perceived exertion(RPE) scale. Results G load was significantly changed along with the process of parachuting. Compared with the baseline, the maximal heart rates at these stages(before parachuting, just jumping, after landing and tactical exercise) were significantly increased(tA =3.75, 4. 90, 19.54, tB=5.66, 4.46, 20. 71, P<0.01). Compared with the baseline, the specific gravity was decreased before and after parachuting (tA = 4.02, 2.77, tB=2.76). Compared with the baseline the RPE scores were enhanced after landing and performing tactical exercise (tA = 3.34, 4.90, 2.89, tB = 3.90, 4.46, 2.90, P< 0.01). However, there were no significant differences of these indices between two groups. Temperature of chest skin in group B was significantly higher than that in group A during parachuting and after landing(tA = 3.99, 2.94, P< 0.05). Conclusions The stress reactions during parachuting training are grossly similar when dressed two kinds of protective system of paratroops ; but the heat stress in group B is higher than that in group A. Key words: Acceleration;  Heart rate;  Urine analysis;  Fatigue;  Paratroops;  Parachuting;  Stress