When it comes to the health of heart times plays an important role. Myocardial infarction (MI), and sudden cardiac deaths occur most frequently in the morning, especially in the first few hours after waking. This is due to the surge in adrenalin and other hormones as we get up and prepare for the challenges of the day.
It has also been noticed that heart attacks also occur more frequently on Mondays. The Monday risk is often blamed on mental stress of a new work-week and the associated increase in activity. There are other reasons too. Bedtimes are usually delayed on weekends, so you end up going to bed late and you have to wake up also early on the first work day of the week. This causes minor sleep deprivation.
Loss of sleep can result in minor increased adrenalin activity and an increase in proinflammatory molecules. Sleep loss is the real culprit behind heart attacks. The average sleep duration has decreased from nine to seven and a half hours during the 20th century. And now it seems there is a chronic sleep deprivation amongst youngsters.
While routine activity in three hours after waking is associated with heart attacks, strenuous activity at any time during the day can do the same, particularly amongst people who do not exercise regularly. This appears to be limited to the first hour after starting exercise. Sex can trigger the onset of heart attack; the absolute hourly risk is so low that the risk from sex is one chance in a million for a healthy individual. Nor is the relative risk increased in people with a history of heart disease.
Heart diseases are common with people unaccustomed to exercise; the best solution is to exercise regularly while avoiding over-exertion. Build up to more vigorous routines gradually. And catch up with plenty of sleep.