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.
But let’s say initially you are not able to push all that hard and you might say to yourself well I can’t get the intensity level up so I may as well do nothing. Wrong statement! Doing something is always better than nothing. It is important to progress over time. For example if you can only start out walking at a slow pace for a half hour that is fine but measure the initial distance you are able to cover in that time. After a month of walking for 30 minutes if you are not walking further distances in that same time frame expect minimal changes in your fitness level.
Another benefit of working out for shorter durations is that folks are more likely to stay consistent over the long run. Let’s face it—life is busy with work, family, social events, etc. The list goes on and on. If you can consistently find a half hour a day and are able to push yourself slightly past your comfort zone, you will get results as long as your nutrition is on track. Focusing on longer duration workouts, however, can cause people to get bored easily. Back when the guidelines suggested we should work out longer, folks tended not to exercise at all because trying to fit in 6 or 7 hours of exercise was overwhelming. Focusing on shorter bout durations is far less intimidating and is more realistic to achieve consistently.
Keeping it Simple
How do you know if you are working out hard enough? The most accurate way to measure aerobic intensity is to check your pulse rate manually or to use a heart rate monitor. Remember, however, that what might be moderate for you, might not be moderate for me, depending on our ages and resting heart rates.
One simplified measuring procedure for aerobic intensity is to use the Talk Test. During aerobic exercise if you can talk out loud very easily, you are most likely not working out hard enough. During aerobic exercise if you have to take more frequent rest breaks from talking, the intensity is considered moderate. If you can’t talk at all then most likely you are working too hard and should slow down. The goal is to get to an intensity level where its comfortable to talk, but yet, you’re unable to hold a really long conversation and long sentences without having to pause for deep breaths.
