While many people struggle working out a couple of times a week, researchers from McMaster University, Hamilton, Canada, have come up with the exact number to get yourself healthy and stay that way. They basically wanted to find out with how little you could get away with, and still improve your health significantly.
They studied two groups of people, one was middle-aged and out of shape, the other was also middle-aged but had been diagnosed with some kind of cardiovascular disease. The patients were tested to determine how fit they were to start off with. The first group was out of shape, but generally healthy.
The patients tried interval training, which means that they had to integrate short periods of very intense exercise interspersed with cool-down periods on a stationary bike. The overall work out was very short. One minute of pedaling at 90% of their maximum, followed by one minute of easy pedaling. This was repeated ten times. This resulted in a 20 minute workout that was repeated twice a week.
The American Heart Association recommends 30 minutes of moderate-intensity exercise five times a week. However, this study indicates that it might not be necessary to spend that much time training or in the gym.