Exercise can help people recover after a heart attack but the benefits vanish when the workout stop, Swiss researchers said. Blood vessel function improved after  four weeks of exercise among people who exercized, but the findings published in the journal Circulation suggest that long-term and continuing physical activity is key to preventing another heart attack.

The Swiss team looked at 209 people who had survived a heart attack to gauge the effects of different types of exercise and what happened when people stopped regular physical activity. Volunteers were assigned to receive training in aerobic exercise , resistance workouts to build strength, or no exercise at all.

After four weeks, blood vessel function in all three exercise group improved, but there were no improvements among those who did not work out. The researchers also found that all positive benefits of working out had vanished among those in the exercise groups who stop physical activity after one month. Doctors know that exercise improves heart function after an attack but how much and what type are unclear.