“If there is any deficiency in food or exercise, the body will fall sick.” Hippocrates Circa 450 BC
There are a number of guidelines out there for activity: be physically active for 30 or more minutes on most days of the week of moderate to vigorous activity- this is the type of activity that makes you sweat and your heart rate increase (World Health Organization) or 150 minutes per week (US Center for Disease Control), or get 10 000 or more steps (recommended by most activity monitor companies).
So which one should be followed and what is good for you?
First, we need to recognize that these guidelines were made when there wasn’t really any studies to say what the best amount of physical activity was. The guidelines were formed by expert opinion. Second, for many of us, we don’t even meet the minimal guidelines so the answer is easy: do more physical activity tomorrow than you are doing today.
The guidelines recommending 30 or more minutes on most days of the week (or 150 minutes per week) were introduced to make it easier to understand. The old guidelines recommended three one hour sessions in your target heart rate range three times per week. These old guidelines gave an all or none impression of activity and were also hard to follow for most people (how many of us know our target heart rate anyway?). It was also believed that even small amounts of activity at a low intensity may be beneficial.
Recent studies have shown that participating in at least 30 minutes or more of activity per day is associated with reductions in early death, heart disease, some cancers (breast, colon) and diabetes compared to people being less active or not active at all. It is also clear that there is a relationship between the amount of activity and the benefits, such that even at activity levels below the guidelines there is a measurable health benefit compared to someone who isn’t active. In addition, participating in more activity than the minimum guidelines results in even greater benefits. As a result, the US Center for Disease Control also suggest that people work towards 300 minutes per week.
But the value of physical activity doesn’t stop there. People participating at levels of activity more than five times the minimum guidelines have even greater benefits to health compared to those who are only just meeting the guidelines. Of note, however, is that the greatest gains appear to be at the low end of activity and that while higher amounts of activity are beneficial, the continued benefit is less pronounced.
With respect to the recommendation of aiming for 10 000 steps per day, this also came about to make it easier to understand and remember (10 000 is a nice round number). How long this may take a person depends mainly on your stride rate (how many steps you take per minute). Let’s say a healthy adult walks 100 steps per minute, therefore it would take this person 100 minutes (1 hour 40 minutes) to accomplish 10 000 steps, which is actually much greater than the activity guidelines of 30 minutes or more per day. Of course, doing that much activity is still very beneficial. The caveat, however, is that the 10 000 steps is a goal of daily total steps not just those during moderate or vigorous activity, so the steps you take while preparing dinner in the kitchen would count, yet that activity wouldn’t count towards the above guidelines of 30 minutes per day. The downside of counting steps is that it doesn’t include activities such as swimming or cycling, so if you like doing those or other non-walking activities, monitoring your step count may not be for you.
When it comes to determining how activity is right for you to improve fitness, mental well-being and health a lot depends on your starting point. If you are already active for more than 30 minutes per day, then you should keep that up (do not lower your activity) and aim for 60 minutes or more per day. Conversely, if you are only walking 2000 steps per day, trying to aim for 10 000 may be a tall order and increasing your activity levels should be done progressively. A good rule of thumb is to increase by no more than 10% per week.
In the next blog I will discuss how to go about fitting physical activity into your life.
This is Part 2 in a series of blog posts entitled Being Active While Living an Active Life.