Activate Your Exercise Hormones

These undercover agents are responsible for almost every benefit you get from working out. Harness their power to burn more fat, build lean muscle, and boost your total health.

- Mirel Ketchiff

Every time you exercise, special hormones in your body spring into action. Released by your system when you move, they give you energy, spark your motivation, and boost your mood. “Hormones are essential for your ability to work out effectively,” says Katarina Borer, a professor of movement science and the director of the Exercise Endocrinology Laboratory at the University of Michigan. “They improve your heart and lung function, they bring fuel to your muscles, and they help your body recover afterwards.” Even so, these exercise hormones are virtually unknown and underappreciated – but that’s about to change.

OSTEOCALCIN

This hormone is produced by your bones when you work out. Its job: to encourage your muscles to absorb the nutrients that help them perform at their peak. “In women, though, osteocalcin production begins to decrease around age 30,” says Gerard Karsenty, the chair of the genetics and development department at Columbia University Medical Center. As levels drop off, he says, your nutrient-depleted muscles can’t work as hard.

Fortunately, regular exercise may bump up your production of osteocalcin, and that extra boost can elevate your performance, Gerard says. His research found that women’s levels were higher after they worked out for 45 minutes; in another study, the muscles of animals that were given a dose of the hormone functioned as effectively as those a fraction of their age. Hit the gym at least every other day to keep your levels up, Gerard suggests.