Exercise could be the heart's fountai...(en the researchers looked at fatty acid ...)

"By that gauge, the women had a better response to exercise training than the men," Soto says. "At this point, the significance of that isn't clear. We know that in animal studies low fatty acid oxidation leads to heart muscle thickening and that when men train their heart muscle often gets thicker than women's. It could be that the increase in fatty acid oxidation in women's hearts with training is a reason why their hearts don't thicken as much."

The study is described in an article that appeared in advance online publication on June 20, 2008 in the American Journal of Physiology. The participants were six men and six women, ages 60 to 75, who were not obese but who had been living an inactive lifestyle. They were put on an eleven-month program of endurance exercise under the careful guidance of a trainer.

For the first three months, they were required to exercise to about 65 percent of their maximum capacity. After that, the program was stepped up so participants reached about 75 percent of maximum. Soto says the volunteers enjoyed the experience and told him they felt in the best shape they had been in years.

The researchers tested the volunteers' heart metabolism before and at the end of their exercise programs by using PET scanning techniques. "Here at the School of Medicine, we are uniquely able to look at the metabolism of the heart because we have the right combination of technology and expertise in cardiology, radiology and radiochemistry," Soto says. "We are one of the few places that can do this kind of study."

Next, the research team will investigate exercise training in individuals with heart failure. "In the past heart failure patients were t
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