Intensive exercise may weaken your heart

Confirming that too much of a good thing can be bad, especially for your heart, researchers have found that over-dose of high intensity exercise may in-crease risks of a heart attack or stroke in those with existing heart disease.For the study, researchers tracked the frequency and intensity of physical ac-tivity and the survival of more than 1,000 people with stable coronary artery heart disease for 10 years.All the participants, most of whom were in their 60s, had attended a cardiac re-habilitation programme to help them exercise regularly and ward off a further heart attack or stroke.The most physically inactive were around twice as likely to have a heart at-tack/stroke as those who were regularly physically active and they were around four times as likely to die of cardiovas-cular and all other causes.But somewhat surprisingly, those who did the most strenuous daily exercise were also more than twice as likely to die of a heart attack/stroke, the findings showed.Another study found that young men undertaking endurance exercise for more than five hours a week may in-crease their risk of developing an irregu-lar heart rhythm in later life.While it seems “counterintuitive” to think that physical activity could aggra-vate heart disease, other smaller stud-ies have also suggested this possibility, experts added, with endurance training in particular, linked to an acute (revers-ible) pro-inflammatory state.