About four years ago, it was suggested that Americans should exercise an hour a day and that the intensity level should be moderate to vigorous. The US Department of Health and Human Services has recently changed its tune and is suggesting reducing the total amount of time to 2 hours and 30 minutes a week of moderate-intensity or 1 hour and 15 minutes of vigorous-intensity aerobic exercise per week for adults.
What? Are you confused? I am and I teach this stuff.
So four years ago we should have been exercising 6 or 7 hours per week and now the government is telling us we can get the same results by exercising for as little as 1 hour and 15 minutes weekly, as long as it is at a vigorous intensity. And what is the difference between vigorous and moderate exercise? Is walking at a slow pace considered moderate exercise or just low intensity activity and would this type of exercise be enough to achieve results?
Less is Better
Well this time, I have to agree with the government. Less is better. There has been an ongoing debate for decades regarding what gets better results: shorter duration and higher intensity or longer duration and lower intensity workouts. During my experience working with clients, I have seen more people achieve results by exercising in shorter bouts at a much higher intensity versus those working out at lower intensities for longer durations.
The reason higher intensity workouts have been getting better results is simple: It all has to do with recovery. When you work out harder your body needs to spend more time recovering afterwards and that mending process burns a lot of calories. For example, you may burn a fair amount of calories while walking at a moderate pace but because the intensity level is not very high, minimal recovery occurs afterwards. It all comes down to pushing hard for a short duration and recovering longer. The recovery process is where the real results happen, not necessarily when you are actually exercising. So if you were to step up to walking more briskly and possibly include some hills and/or jogging in bouts your body will require more time to recover and burn more calories.
