A simple question deserves a simple answer. Unfortunately, in the case of the amount of Physical Activity we should be doing to stay healthy, this is a difficult thing to do. This situation isn’t helped by the continued publication of confusing and conflicting headlines.
Let’s take the past week or so as an example; two headlines sat side-by-side in a popular online UK newspaper one telling us that 30-minutes of brisk walking five times a week is better than going to the gym for losing weight and the other saying that we should be doing double or even quadruple the recommended 150-minutes of moderate to vigorous intensity exercise each week if we want to keep our hearts healthy. Putting aside the limitations of both studies for a moment, we can probably say that both of these headlines have an element of truth.
Well, the first thing to do is to change the way you think about Physical Activity. Stop thinking only about the 30-minutes of exercise you do five times a week to meet the government guidelines, think instead about everything that makes you move. Physical Activity has many dimensions, each known to have clear biological and health benefits – from the amount of time you spend sedentary each day to your daily calorie burn, not forgetting the time you spend doing moderate-to-vigorous intensity activity each week. They all have a part to play in keeping you healthy.
Most research focuses on structured exercise, just like the report from The London School of Economics which was reported in a number of newspapers to show brisk walking is better than the gym for weight loss. The study didn’t actually compare the effects of the different types of activity directly, so we can’t say for sure which one was best or if one is truly better than the other. In fact, this was a cross-sectional study; it only looked at activity at one time point, so can’t make any conclusions about weight loss over time.
It will come as no surprise that people who did more activity of any kind had the lowest body mass index (BMI) and waist measurements. These effects were strongest in women and in people over the age of 50. Men who walked briskly for 30-minutes five days a week had a BMI on average one unit less than those who didn’t do this amount; the difference was 1.8 units for women. The equivalent amount of sport or exercise, heavy manual work, or heavy housework (for women only) were also linked with a lower BMI, it was just that the difference was smaller.
In fact, to get the most bang for your buck in terms of body weight, another recent study suggests we need to be active for at least 150-minutes a week and stand up for most of the day. The research published this month in the Mayo Clinic Proceedings showed that achieving this amount of activity gave some benefit, but standing up and being active gave additional benefit – the more time people spent standing the lower their odds of obesity and metabolic syndrome.
But remember, the outcome researchers are looking at is really important. These two studies both focused on measures of obesity, whereas the other study I mentioned earlier wanted to know about heart failure – two very different, although undeniably related outcomes (being overweight can increase your risk of heart problems). The amount of activity we need to do probably depends on what we are trying to achieve.
So, what should we do?
Simply put, we should sit less and move more. Research tells us that the more we move, the lower our risk of developing any number of preventable diseases. Importantly, it likely doesn’t matter what specific activity we choose to do, just as long as it increases our calorie burn at least three times our resting rate (i.e. is at least moderate-intensity for us). Chances are we are all doing at least one thing each day that meets this criterion – we just need to find out what that activity is for us – it could be anything from walking the dog or playing with the kids to 18-holes of golf or a Spinning class. We should also spend less time sitting or standing still – moving more will help with this.
The personalised multidimensional physical activity profiles visualised in the KiActiv system, created by our partners at the University of Bath, enhance understanding and inspire confidence to change and optimise your individual physical activity to benefit your health – one size doesn’t fit all!