Author(s): XU, Y., LU, J., TANG, Q., ZHANG, Y., YAO, Y., ZU, J., XIAO, H., Institution: NANJING SPORT INSTITUTE, Country: CHINA, Abstract-ID: 2007

INTRODUCTION:
Both aerobic exercise and intermittent fasting can improve weight loss, yet their effects on heart health differ: exercise primarily enhances antioxidant capacity, whereas fasting modulates energy metabolism[1-2]. This suggests distinct impacts on high-fat diet-induced mitochondrial dysfunction in the myocardium. This study aimed to compare the efficacy of aerobic exercise versus intermittent fasting in improving myocardial mitochondrial function in obese rats.
METHODS:
Fourteen rats were fed with regular diet, while forty-two rats were fed with high-fat diet. They were randomly divided into the normal control group (NC, n=14), the high-fat control group (HC, n=14), the high-fat exercise group (HE, n=14), and the high-fat fasting group (HF, n=14). Rats in the HE group performed treadmill running for 8 weeks (5 days/week, 40–60 minutes/day, at 15 meters/minute). Rats in the HF group were fasted on Wednesday and Friday in odd weeks and on Tuesday and Saturday in even weeks, while they had normal diet at other times. Extract the myocardial mitochondria and conduct tests on their respiratory function, fatty acid oxidation capacity, and membrane potential to evaluate the related functions of myocardial mitochondria.
RESULTS:
1)Compared with NC group, the mitochondrial FAO, RCR, JC-1, ROS, and ATP levels in HC group of rats were significantly lower (3193.63±374.64vs1995.00± 399.15,6.01±1.64vs3.85±0.44,1.84±0.19vs1.61±0.07,8181.14±4474.86vs16307.17±4972.06,15.54 ± 2.21vs6.09±1.52)(P < 0.05).
2)After 8 weeks of exercise and intermittent fasting, the FAO , RCR , JC-1, ROS, and ATP in HE and HF group were significantly improved(2736.63±688.89vs2286.00 ±438.72,6.65±1.73vs7.24±1.22,1.82±0.07vs1.88±0.07,9908.57±2762.11vs12882.71± 7476.29,12.54±2.88vs10.24±3.44), and the changes in HE group were more significant than those in HF group. (P < 0.05).
CONCLUSION:
A high-fat diet leads to dysfunction of the mitochondria in the heart muscle. Both aerobic exercise and intermittent fasting can alleviate oxidative stress in the heart muscle mitochondria, restore respiratory efficiency, stabilize membrane potential, and enhance synthesis, effectively improving the metabolic and bioenergetic functions of the heart muscle mitochondria. The improvement trend of aerobic exercise is more obvious compared to intermittent fasting, suggesting that it may have a more significant effect in directly enhancing the metabolic adaptability and mitochondrial quality of the heart muscle.
References:
[1] Tang X. Sodium butyrate protects against oxidative stress in high-fat-diet-induced obese rats by promoting GSK-3β/Nrf2 signaling pathway and mitochondrial function. J Food Biochem. 2022 Oct;46(10):e14334.
[2] Guevara-Cruz M. Intermittent fasting, calorie restriction, and a ketogenic diet improve mitochondrial function by reducing lipopolysaccharide signaling in monocytes during obesity: A randomized clinical trial. Clin Nutr. 2024 Aug;43(8):1914-1928.