Keep your heart young. Exercise!

Here’s yet another reason why you should exercise: It makes your heart stay young, says a new research on adults. The study conducted at Washington University School of Medicine in St Louis, showed that older people who did endurance exercise training for about a year ended up with metabolically much younger hearts.

Women benefit more

The researchers also showed that by one metabolic measure, women benefited more than men from the training. “Past research has suggested that exercise can reverse some effects of aging, and we wanted to see what effect it would have specifically on the heart,” said first author Pablo F Soto, MD, instructor in medicine in the Cardiovascular Division. The participants in the study were men and women 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 guidance of a trainer.

The secret’s exercise

To reach the conclusions, the research team measured heart metabolism in sedentary older people both at rest and during administration of dobutamine, a drug that makes the heart race as if a person were exercising vigorously.

For the first three months, the participants were required to exercise to about 65 per cent of their maximum capacity. After that, the program was stepped up so they reached about 75 per cent of maximum. At the start, they found that in response to the increased energy demands produced by dobutamine, the hearts of the study subjects didn’t increase their uptake of energy in the form of glucose (blood sugar).

But after endurance exercise training – which involved walking, running or cycling exercises three to five days a week for about an hour per session – the participants’ hearts doubled their glucose uptake during high-energy demand, just as younger hearts do.

Young at heart!

Soto explains that if heart muscle doesn’t take in glucose in response to increased energy needs, it goes into an energy-deprived state, which may raise the risk of heart attack. But if it can increase glucose uptake, the heart is better protected against ischemia (low oxygen) and heart attack.

Based on heart glucose metabolism, both the men and women in the study had the same rejuvenating benefit from their exercise programs. But the heart uses both glucose and fatty acids for energy. And when the researchers looked at fatty acid metabolism, they found a striking difference in the results of exercise training between women and men.

In the men, the heart’s fatty acid metabolism dropped in response to increased energy demand, but it went up in women. The study has been published in the American Journal of Physiology.