The “Secret Sauce” of Exercise?

Have We Discovered the “Holy Grail” Of Hunger Hormones?

We know that sometimes, after exercise, we feel hungry, while, at other times, we don’t want to eat. Why is that? A recent study, published in Nature magazine, offers one answer. Scientists tested multiple chemicals which were released in the bloodstreams of mice after strenuous exercise, and found one had increased dramatically. This compound, a combination of lactic acid and the amino acid phenylalanine, appears to be produced in reaction to the buildup of lactic acid in muscle after strenuous exercise.

The scientists gave this compound, called lac-phe, to obese mice and found they ate much less. The same reaction wasn’t seen in lower-weight mice. The scientists then bred mice who don’t produce lac-phe and found that they, even after strenuous exercise, continued to eat as much as when they were sedentary.

Eight healthy men had their lac-phe measured after three different bouts of exercise: 90 minutes of leisurely biking, lifting weights, and a series of 30-second sprints on a stationary bike. Lac-phe levels were highest after the sprints, followed by weight training.

This research is preliminary, but offers one possible suggestion to help those of use who struggle with appetite after exercise: make your workouts more intense, whether aerobic or using weights.