Training for the Body

ennifer Cassetta, a martial arts instructor in New York City, claims she never gets sick, and neither do her father and grandmother, who also teach martial arts. "I believe it is the holistic approach to exercise that calms the mind and relieves stress," she says. "And the cardio, strengthening, and conditioning help boost the immune system."

Cassetta says her health has changed dramatically after she picked up martial arts eight years ago. Before then, she was a smoking, take-out-every-night, espresso-drinking girl in her 20s.

"As I started to train, I started to change my habits drastically," she says. "I cleaned up my diet, trained more, and quit smoking. Now in my 30s, I have more energy, I look better, and am stronger than I ever have been."

One bout of vigorous exercise can increase circulation, says Christiane Northrup, MD, author of Women's Bodies, Women's Wisdom. "Whenever circulation is increased, you get far more white blood cells," she says, "so they check for foreign germs and are far more apt to be able to gobble them up."