Intermittent fasting,as a dietary nutrition program of fasting and eating alternately,mainly includes alternate-day fasting,time-restricted fasting,periodic fasting and Ramadan fasting.Positive effects of intermittent fasting on metabolic disea-ses such as obesity,diabetes and cardiovascular disease has been confirmed,but its effect on exercise performance is yet to be re-vealed.This paper summarizes the effects of intermittent fasting on anaerobic exercise,aerobic endurance exercise and strength alternation as well as related mechanism.It can provide theoretical reference for diet optimization,intermittent fasting selection and scientific exercise amony athletes,sports enthusiasts and patients with chronic diseases.

Objective:To investigate the interventional effect of metformin on pulmonary inflammation and pulmonary fibrosis in silicotic rats.Methods:In April 2019, 48 Wistar male rats of SPF grade were randomly divided into negative control group, metformin control group, silicon dioxide (SiO 2) model group, low, medium and high dose metformin intervention group according to the random number table method, 8 rats in each group. The SiO 2 model group and the low, medium and high dose metformin intervention groups were given 1 ml 50 mg/ml of SiO 2 by intratracheal instillation, the negative control group and the metformin control group were given 1 ml normal saline by intratracheal instillation. 24 hours later, the low, medium and high dose metformin intervention groups and the metformin control group were treated with 100, 200, 400 and 400 mg/kg metformin daily, the control and SiO 2 model groups received normal saline daily. Then the rats were sacrificed at the 28th day after SiO 2 exposure. The changes of rat body weight and pathological examination of rat lung tissue were observed, and the lung organ coefficient, the content of hydroxyproline (HYP) , the expression levels of inflammatory factors transforming growth factor beta1 (TGF-β1) , tumor necrosis factor-alpha (TNF-α) , interleukin-1beta (IL-1β) and the protein expression of E-cadherin (E-Cad) , Vimentin, α-SMA were detected. Results:Compared with the negative control group, SiO 2 model group had a significant decrease in the body weight of rats ( P<0.05) , lung organ coefficient, alveolitis and fibrosis scores, HYP content and the levels of TGF-β1, TNF-α, IL-1β were all significantly increased ( P<0.05) . Compared with the SiO 2 model group, the weights of the rats in the medium and high dose intervention group of metformin increased significantly ( P<0.05) . And after intervention with different doses of metformin, the lung organ coefficient, alveolitis and fibrosis scores, HYP content and the levels of TGF-β1, TNF-α and IL-1β were significantly decreased ( P<0.05) . Immunohistochemistry and Western blotting results showed that compared with the negative control group, the expression of E-Cad of the SiO 2 model group was decreased, and the expression levels of Vimentin and α-SMA were significantly increased ( P<0.05) . After metformin intervention, the expression of E-Cad was significantly increased, the expression levels of Vimentin and α-SMA were significantly decreased ( P<0.05) . Conclusion:Metformin can reduce lung tissue inflammation and fibrosis in rats exposed to SiO 2 dust, which may be related to reducing the expression of inflammatory factors in lung tissue and inhibiting the EMT process.

Objective:To investigate the interventional effect of metformin on pulmonary inflammation and pulmonary fibrosis in silicotic rats.Methods:In April 2019, 48 Wistar male rats of SPF grade were randomly divided into negative control group, metformin control group, silicon dioxide (SiO 2) model group, low, medium and high dose metformin intervention group according to the random number table method, 8 rats in each group. The SiO 2 model group and the low, medium and high dose metformin intervention groups were given 1 ml 50 mg/ml of SiO 2 by intratracheal instillation, the negative control group and the metformin control group were given 1 ml normal saline by intratracheal instillation. 24 hours later, the low, medium and high dose metformin intervention groups and the metformin control group were treated with 100, 200, 400 and 400 mg/kg metformin daily, the control and SiO 2 model groups received normal saline daily. Then the rats were sacrificed at the 28th day after SiO 2 exposure. The changes of rat body weight and pathological examination of rat lung tissue were observed, and the lung organ coefficient, the content of hydroxyproline (HYP) , the expression levels of inflammatory factors transforming growth factor beta1 (TGF-β1) , tumor necrosis factor-alpha (TNF-α) , interleukin-1beta (IL-1β) and the protein expression of E-cadherin (E-Cad) , Vimentin, α-SMA were detected. Results:Compared with the negative control group, SiO 2 model group had a significant decrease in the body weight of rats ( P<0.05) , lung organ coefficient, alveolitis and fibrosis scores, HYP content and the levels of TGF-β1, TNF-α, IL-1β were all significantly increased ( P<0.05) . Compared with the SiO 2 model group, the weights of the rats in the medium and high dose intervention group of metformin increased significantly ( P<0.05) . And after intervention with different doses of metformin, the lung organ coefficient, alveolitis and fibrosis scores, HYP content and the levels of TGF-β1, TNF-α and IL-1β were significantly decreased ( P<0.05) . Immunohistochemistry and Western blotting results showed that compared with the negative control group, the expression of E-Cad of the SiO 2 model group was decreased, and the expression levels of Vimentin and α-SMA were significantly increased ( P<0.05) . After metformin intervention, the expression of E-Cad was significantly increased, the expression levels of Vimentin and α-SMA were significantly decreased ( P<0.05) . Conclusion:Metformin can reduce lung tissue inflammation and fibrosis in rats exposed to SiO 2 dust, which may be related to reducing the expression of inflammatory factors in lung tissue and inhibiting the EMT process.