Archive for May 3rd, 2018

Stand and deliver. One line man

Pretty much everyone knows that taking exercise helps people stay in good health. It staves off chronic ailments like type 2 diabetes and heart disease and – maybe – helps us live longer.

Until recently, however, the prevailing view among both policy people and researchers was that you only got benefits from moderate to vigorous exercise – the kind that gets you at least slightly out of breath, such as brisk walking, doing sport or going to the gym. Health authorities and the media focused their public health messages accordingly.

But while many people are still not doing as much strenuous exercise as they should, another creeping trend has been taking place. The modern way of living has almost removed the need to move: from Netflix to searching for air tickets to holding virtual meetings, so much of what we do now is at the touch of a button.

There has been a dramatic drop in how much we move around our houses and workplaces. Much of the time we used to spend on the move is now spent sitting, as this chart shows:

Adapted from Ng et al (2012). Time use and physical activity: a shift away from movement across the globe.

While we have very good evidence about how vigorous exercise affects our health, little is known about this disappearing background of daily light activity. This is what we wanted to find out in the study we have just published in the British Journal of Sports Medicine. The results may make a big difference to how we view exercise in future.

What we found

We wanted to understand how daily light physical activity affects people’s metabolic health and their risk of premature death. We carried out a meta-analysis, searching through all the research published to date and averaging out the combined results.

We looked at both laboratory studies of groups of around ten to 40 participants, which show what happens immediately to our bodies when we interrupt long periods of sitting; and long-term studies of thousands of people, which provide insight into the effects of light exercise over several years.

We found that doing twice as much light activity cuts your risk of premature death by almost 30%. This was even after accounting for levels of moderate to vigorous activity and other factors such as smoking.

This means that if you increase the amount you move around each day from one hour to two hours, for example, you cut your risk by 30%. But if you currently do three hours and you raise it to six hours, you cut your risk by the same amount. It’s a law of diminishing returns: if you do little to start with, you get a big benefit because your initial risk is so high.

We also found that moving around positively affects the way the human body regulates blood sugar and insulin in the short term. This matters because our bodies only function adequately when blood sugar levels remain constant. If the blood sugar or insulin become too high, it can lead to serious health complications.

Walk of life. Umamuna

When a person interrupts sitting with a few minutes of light activity such as slow walking, we found it reduced blood sugar and insulin levels by about 20% to 25% on average. People with type 2 diabetes enjoy even greater benefits, suggesting this might be a good way for them to control their blood sugar.

It is worth noting some limitations to our study. This is a relatively new research area, so we were aggregating only a modest amount of evidence.

The longer term studies that we incorporated mostly relied on people reporting how much light activity they were doing. People often find it difficult to accurately recollect the time they spend being active.

There is also the possibility that people who are more ill in the first place do less activity: in other words, they’re moving less because they are ill, and the illness rather than the lack of exercise might be the reason they died prematurely. If so, it would be skewing our numbers.

This possibility means we cannot definitively say that light physical activity reduces the risk of premature death. The short-term lab studies do suggest our conclusion is right, but we don’t know if these effects are longlasting. This crucial part of the puzzle still needs resolved.

What now

There is still no doubt that moderate to vigorous activity is more potent: you would perhaps need to do about four minutes of light activity to get the same benefit as one minute of more strenuous activity.

But our study, which is the first meta-analysis in this area, is great news for people who find it hard to add exercise into their weekly routine, as it gives them more options.

We can start thinking about how to help very inactive and sedentary people incorporate more light activity into their daily routine as a stepping stone towards a more active lifestyle. It also raises possibilities for people who are physically unable to do strenuous exercise.

Any which way. C Jones

The next question is how much light exercise we should ideally do. Our study could not answer this because there are not enough research findings yet. The precise amount is likely to depend on how we spend the rest of our day – including how much exercise we take, and how much we sit and sleep.

For now, the message is, “Move more at any intensity – the more the better.” Eminent health authorities in the likes of the US have already started giving this advice, which is very encouraging. While we researchers build up a more detailed picture, readers would be well advised to get vertical.



Read Full Post »

Photo: @shauna_harrison

Getting in shape has become virtually synonymous with “carve the body into a given physical ideal.” We glorify the six-pack, celebrate the bikini body, and are on this hamster wheel chasing aesthetic greatness. Having been part of the fitness industry for 22 years, I am well aware that, from a marketing standpoint, the six-packs, bikini bodies, and booty-lifting appeal affect people’s desires, in terms of imagery as much as verbiage.

I do think that as an industry, though, we have a responsibility to direct the conversation and tell the whole story. Yes, a beautiful body is sexy. But do you know what else is sexy? Living longer. Living fully. Living at our maximum physical and cognitive function. Living at our greatest potential for as long as possible. And none of these things require a sculpted physique to achieve. They can, however, be achieved with regular and consistent physical activity.

The 2018 Physical Activity Guidelines Advisory Committee of the U.S. Department of Health and Human Services has recently released its annual scientific report of the most current evidence about the disease prevention and health promotion benefits of physical activity. Ten more years of research has given further evidence to the breadth of health benefits that can be attributed to physical activity.

Here’s a snapshot of the easily overlooked benefits of working out.

Quality of sleep

Quality of sleep has been linked numerous times to workout patterns, meaning a number of things like deeper and longer sleep cycles have been attributed to greater amounts of moderate to vigorous physical activity. And this applies to those who have sleep-related disorders and those who do not. Many of these benefits can happen almost immediately.

Improved daily activity

Increased physical activity leads to improved physical function across all ages. Those who engage in more physical activity are able to perform daily tasks more easily, and in older populations this also slows the loss of age-related physical function. In other words, you can move better for longer.

Enhanced brain function

Executive function refers to the processes of the brain needed to concentrate and pay attention, often broken down into inhibition, working memory, and cognitive flexibility. Some examples of this process include things such as organization, planning, reasoning, self-monitoring, and controlling emotions. Even a single bout of physical activity can improve your executive function for a period of time. Plus, exercise helps reduce stress levels, which makes for a happy and healthy brain.

Manage mental health

Regular exercise has been said to help reduce depression and anxiety levels—even pregnant women who are more physically active have less risk of postpartum depression as well. Some of these benefits happen almost immediately.

Reduce risk of all-cause mortality

You can decrease your chance of all-cause mortality even with the slightest increase in physical activity. This is even more important if you tend to lead a more sedentary lifestyle. Additionally, consistent exercise can help reduce your risk of cardiovascular mortality and mortality from colorectal cancer, breast cancer, or prostate cancer. For those who already have a chronic condition, exercise may also help with symptoms and chronic conditions.

Even small bouts of activity of any length of time count in a daily accumulated total of activity and contribute to these myriad benefits. Moving your body is incredibly important for your health and even more beneficial when you enjoy doing so. As studies have shown, those who are physically active sleep better, feel better, function better—and ultimately, lead happier and more fulfilled lives.


Read Full Post »

%d bloggers like this: