Objective:To evaluate the training efficacy of the autonomic nervous system stability assessing and enhancing capsule (hereinafter referred to as the EC), and to study the difference in physiological indicators for autonomic nervous system stability training between the EC and a non-capsule environment.Methods:A total of 1 478 male military pilots under autonomic nervous system stability training between February 2022 and February 2024 were selected before they completed training sessions in both the EC and a non-capsule environment. The pre-training time-domain and frequency-domain indices of heart rate variability (HRV) and the 0.1 Hz index were compared with the post-training ones, and across difficulty levels (low, moderate, and high). The difference that the EC made in relaxation training was analyzed.Results:①Time-domain indices of HRV were of statistical significance in the main effects of training difficulty, those of training environments, and their interactions ( F=4.40-160.80, all P<0.05 or 0.01). Simple effect analysis revealed that in the same phase of training the standard deviation of all NN intervals (SDNN) at the low level of difficulty in the EC was lower than in the non-capsule environment. However, all time-domain indices after training were higher in the EC than in the non-capsule environment. The differences were statistically significant (all P<0.05 or 0.01).②For frequency-domain HRV indices, significant differences were observed in both the main effect of training difficulty and the interactions ( F=4.40-1 524.33, all P<0.01). Very low frequency power (VLF), high frequency (HF), the ratio of low frequency to high frequency (LF/HF), normalized low frequency (LFnorm), and normalized high frequency (HFnorm) were significantly different in the main effect of training environments ( F=4.24, 12.00, 6.91, 23.39, 23.39, P=0.040, <0.001, =0.009, <0.001, <0.001). Simple effect analysis revealed that at the same level of training difficulty, the EC delivered significantly lower values of LF and LFnorm but higher values of HF and HFnorm than the non-capsule environment before training (all P<0.05). VLF across levels of training difficulty and LF/HF at the high level of difficulty level were significantly lower in the EC than in the non-capsule environment. After training, total power, VLF, LF, HF, and HFnorm were significantly higher in the EC than in the non-capsule environment, but LF/HF and LFnorm were significantly lower (all P<0.05). ③For the 0.1 Hz index, significant differences were observed in both the main effect of training difficulty and the interactions ( F=2 147.75, 6.63, both P<0.001). Subsequent simple effect analysis revealed that at the same level of training difficulty, 0.1 Hz indices of pilots in the EC were lower than in the non-capsule environment before and after training (all P<0.01). Conclusions:During the autonomic nervous system stability training, the EC can effectively and quickly regulate and alleviate pilots′ fatigue and stress. Furthermore, it provides sustained autonomic nervous system training, thereby stabilizing pilots′ autonomic nervous system.

Objective:To evaluate the training efficacy of the autonomic nervous system stability assessing and enhancing capsule (hereinafter referred to as the EC), and to study the difference in physiological indicators for autonomic nervous system stability training between the EC and a non-capsule environment.Methods:A total of 1 478 male military pilots under autonomic nervous system stability training between February 2022 and February 2024 were selected before they completed training sessions in both the EC and a non-capsule environment. The pre-training time-domain and frequency-domain indices of heart rate variability (HRV) and the 0.1 Hz index were compared with the post-training ones, and across difficulty levels (low, moderate, and high). The difference that the EC made in relaxation training was analyzed.Results:①Time-domain indices of HRV were of statistical significance in the main effects of training difficulty, those of training environments, and their interactions ( F=4.40-160.80, all P<0.05 or 0.01). Simple effect analysis revealed that in the same phase of training the standard deviation of all NN intervals (SDNN) at the low level of difficulty in the EC was lower than in the non-capsule environment. However, all time-domain indices after training were higher in the EC than in the non-capsule environment. The differences were statistically significant (all P<0.05 or 0.01).②For frequency-domain HRV indices, significant differences were observed in both the main effect of training difficulty and the interactions ( F=4.40-1 524.33, all P<0.01). Very low frequency power (VLF), high frequency (HF), the ratio of low frequency to high frequency (LF/HF), normalized low frequency (LFnorm), and normalized high frequency (HFnorm) were significantly different in the main effect of training environments ( F=4.24, 12.00, 6.91, 23.39, 23.39, P=0.040, <0.001, =0.009, <0.001, <0.001). Simple effect analysis revealed that at the same level of training difficulty, the EC delivered significantly lower values of LF and LFnorm but higher values of HF and HFnorm than the non-capsule environment before training (all P<0.05). VLF across levels of training difficulty and LF/HF at the high level of difficulty level were significantly lower in the EC than in the non-capsule environment. After training, total power, VLF, LF, HF, and HFnorm were significantly higher in the EC than in the non-capsule environment, but LF/HF and LFnorm were significantly lower (all P<0.05). ③For the 0.1 Hz index, significant differences were observed in both the main effect of training difficulty and the interactions ( F=2 147.75, 6.63, both P<0.001). Subsequent simple effect analysis revealed that at the same level of training difficulty, 0.1 Hz indices of pilots in the EC were lower than in the non-capsule environment before and after training (all P<0.01). Conclusions:During the autonomic nervous system stability training, the EC can effectively and quickly regulate and alleviate pilots′ fatigue and stress. Furthermore, it provides sustained autonomic nervous system training, thereby stabilizing pilots′ autonomic nervous system.