You may turn to exercise as a means to promote weight loss — but it's important to remember that intense physical activity can make you feel hungry. If your goal is to lose weight, you might wonder if exercise can work against you instead of for you. Consult your doctor before beginning any new exercise regimen.
Two chief hormones are responsible for controlling appetite in the body, the Science Daily website reports. Ghrelin stimulates your appetite, causing you to feel hungry. Peptide YY is responsible for suppressing your appetite. Exercise can affect both these hormones.
Research at Loughborough University in the United Kingdom found that various types of exercise affect the appetite differently, Science Daily reported in 2008. The study found that after a 60-minute treadmill exercise session, the body released both ghrelin and peptide YY. A 90-minute weightlifting session, however, released only ghrelin, which stimulates appetite.
Another study, published 2007 in the "Journal of Endocrinology," found that hunger lessened during exercise, but increased afterward — and when the exercisers sat down to eat, they ate more. Researchers theorized this could be because the body was working to equal the calories burned during an exercise session.
Immediately after exercising, the body’s temperature is elevated, the Health and Study website explains. Especially when you perform vigorous exercise, the body temperature can result in reduced hunger. However, as body temperature decreases, appetite increases, the "Boston Globe" reported in 2008. At this time, the body also may be burning more calories due to increased metabolic rate.
Regardless of its effects on appetite, exercise benefits your body in ways besides weight loss, University of Arkansas exercise physiologist William J. Evans told the "Globe." “Even if you do not lose weight, regular exercise will greatly reduce your risk of chronic disease and extend your life expectancy,” Evans said. Evans also noted that you shouldn't use your exercise program as an excuse to get lazy after your workout. “There is also evidence that many people who initiate an exercise program compensate by becoming less active for the rest of the day,” he added.
Because your body works to equalize itself, appetite levels can increase to compensate for calories burned while exercising, the "Globe" reported. For this reason, exercise not complemented by a healthy diet may not contribute to weight loss alone, according to Stanford University professor Dr. James Fries told the newspaper.