Intense exercise suppresses appetite more strongly than light exercise

Vigorous exercise suppresses hunger in healthy people to a greater extent than moderate exercise, and women may be particularly susceptible to a like response, according to a small study published in the Journal of the Endocrine Society.

The study examined the effect of exercise intensity on ghrelin hormone levels and appetite in men and women. Ghrelin is known as the “hunger hormone” and is related to the feeling of needing to eat.

“We found that high-intensity exercise suppressed ghrelin levels to a greater extent than moderate-intensity exercise,” says lead study author Kara Anderson, PhD, of the University of Virginia in Charlottesville, VA. “In addition, we found that people felt less hungry after high-intensity exercise compared to moderate-intensity exercise.”

Ghrelin circulates in acylated (AG) and deacylated (DAG) forms, which are known to affect appetite. Data on the effects of exercise intensity on AG and DAG levels and their effects on appetite are few and mostly limited to men, the study notes.

To address this gap, eight men and six women participated in the study. Participants fasted overnight and then exercised at various intensities (the degree of which was determined by blood lactate levels), followed by a self-assessment of appetite.

Women had higher levels of total ghrelin at baseline compared to men, the study noted. But according to the study, only women showed a “significant reduction in AH” after intense exercise.

“We found that moderate-intensity exercise either did not alter ghrelin levels or caused them to increase,” the study said. The findings suggest that exercise above the lactate threshold may be necessary to induce suppression of ghrelin levels.

The researchers also acknowledged that more work is needed to determine how much of the effect of exercise depends on gender.

Ghrelin has been shown to have a wide range of biological effects in aspects such as energy balance, appetite, glucose homeostasis, immune function, sleep and memory.

“Exercise should be viewed as a ‘medicine’ where the ‘dose’ should be tailored to the individual’s personal goals,” says Anderson.

This study shows that high-intensity exercise may be important for appetite suppression, which can be especially helpful as part of a weight loss program.