To provide references for promoting the anti-G ability of flying cadets and improving the training methods by testing the flying cadets′ relaxed +G_z tolerance and analyzing the related factors.

Fifty-seven healthy male flying cadets were tested for anti-G ability by cluster sampling. The indicators included relaxed +G_z tolerance, maximal pedal force of lower limbs, maximal expiratory pressure (MEP) and maximum inspiratory pressure (MIP). The subjects were divided into high and low tolerance groups, and the low tolerance group was divide into 2 groups by judging if they were with or without visual change. The subjects were divided into high and low limbs strength groups by measured maximal pedal force. The questionnaire was used to get the information of human centrifuge test and the physical training of flying cadets at ordinary time. According to the results of the questionnaires, the subjects were divided into low strength (≤3 times/week) and high strength (>3 times/week) physical training groups by aerobic training intensity.

Relaxed +G_z tolerance test results of the flying cadets were 3.5 G and 4.0 G, with an average of (3.56±0.17) G. Maximal pedal force of lower limbs was averagely (449.3±105.6) kgf (1 kgf=9.806 N). MEP was averagely (20.1±3.5) kPa. MIP was averagely (10.5±2.3) kPa. MEP of 4.0 G group was higher than that of 3.5 G group, and the difference was significant (t=2.08, P=0.043). In the subjects of 3.5 G relaxed +G_z tolerance, MEP of unchanged vision group was higher than that of changed vision group, and the difference was significant (t=2.35, P=0.023). Relaxed +G_z tolerance of high pedal force group (≥449.3 kgf) was higher than that of low pedal force group (<449.3 kgf), and the difference was significant (t=2.20, P=0.035). 66.7% of the subjects did not learn correct anti-G maneuver; 91.2% of the subjects took long-distance running; 82.5% of the subjects took strength training; 57.9% of the subjects did lower limbs strength training, but 45.6% of them did not understand the correct methods of training muscle groups. MEP of the high training group was higher than that of low training group, and the difference was significant (t=3.25, P=0.002). Maximal pedal force of lower limbs in the high training group was lower than that in the low training group, and the difference was significant (t=2.35, P=0.022).

The flying cadets′ anti-G ability is not good in centrifuge. They should be arranged to experience and trained in human centrifuge as early as possible. Anti-G physical training should be enhanced based on anaerobic exercise.

Acceleration; Hypergravity; Physical endurance; Questionnaires; Physical training; Flying cadets