Low to moderate-intensity exercise may prevent metabolic conditions and atherosclerosis in young people

"An acute bout of exercise at 40 %, 60 %, and 70 % VO2 max 12 h before intake of a fat-meal had similar effects on PHTG attenuation," the researchers reported. "Also, there was an improvement in insulin sensitivity among all exercise trials, leading to decreased insulin response to fat-rich meal."

The randomized controlled trial found that compared to no exercise, low-intensity exercise on a treadmill for 1 hour significantly lowered serum triglyceride levels following a fat-rich meal that was ingested 12 hours post-exercise

Cardiovascular disease (CVD) is the foremost cause of death worldwide. Postprandial hypertriglyceridemia is a condition characterized by elevated triglyceride levels after a meal. It is a common lipid abnormality linked to an increased CVD risk.

Previous studies showed that exercising at 40-70% intensities not only attenuates PHTG but also lowers insulin response among physically inactive people with metabolic syndrome. However, there is a need to elucidate the effects of different exercise intensities on insulin resistance and PHTG in healthy individuals (non-hyperlipidemic). Therefore, John Q. Zhang, Department of Kinesiology, The University of Texas at San Antonio, USA, and colleagues aimed to investigate the effects of different exercise intensities on insulin resistance and postprandial lipemia (PHTG) in healthy individuals.

The study included 10 adult males (age = 34 ± 2.8 y, fasting plasma TG = 1.36 ± 0.18 mmol/l, body mass = 72.9 ± 2.4 kg, VO2max = 43.7 ± 3.0 ml/kg/min, fasting Homeostatic Model Assessment for Insulin Resistance (HOMA2-IR) = 1.7 ± 0.3, and fasting glucose = 5.2 ± 0.2 mmol/l) with normal fasting triglyceride (TG) concentrations.

Each participant performed a control trial (Ctr, no exercise), and three exercise trials at 40 % (40%T), 60 % (60%T), and 70 % (70%T) of their VO2 max. In the exercise trials, participants jogged on a treadmill for one hour at a designated intensity. Each participant consumed a fat-rich meal 12 hours after exercise. Blood samples were taken at 0 h (before the meal), and 2 h, 4 h, 6 h, 8 h, and 24 h after the meal. After the meal, they analyzed the plasma TG, HOMA2-IR, and area score under the TG concentration curve over an 8 period (TG tAUC).

The study led to the following findings:

• At 2 h, 4 h, and 6 h after the meal, TG in all exercise trials was lower than Ctr but did not differ.
• All the exercise trials were lower in TG tAUC scores than Ctr, but differences were not observed among the exercise trials.
• Compared to Ctr, a significant difference in HOMA2-IR in both 60 % T and 70 % T was observed, but not in 40 % T.

"These findings indicate that exercising at low to moderate intensity may be sufficient in preventing metabolic conditions and atherosclerosis among young, healthy, and recreationally active individuals," the researchers wrote.

"These results may provide exercise-oriented health promotion measures for communities with healthy and at-risk individuals," they concluded.

Reference:

Ji, L. L., Fretwell, V. S., Escamilla, A., Yao, W., Zhang, T., He, M., & Zhang, J. Q. (2023). An acute exercise at low to moderate intensity attenuated postprandial lipemia and insulin responses. Journal of Exercise Science & Fitness, 22(1), 14-22. https://doi.org/10.1016/j.jesf.2023.10.006