Lack of exercise 'twice as deadly' as obesity

Just 20 minutes of brisk walking a day may be all it takes to lessen a sedentary person's risk of early death, says a new study. The researchers also found the risk of early death due to lack of exercise is double that posed by obesity and does not necessarily depend on being obese or overweight.

Just 20 minutes a day brisk walking can cut risk of early death in inactive people, study says.

These were the conclusions of the team that analyzed the data on over 334,000 men and women taking part in a large European study looking at the links between cancer and diet that also measured many other variables such as exercise and Body Mass Index (BMI).

When they analyzed the data, the researchers found that compared with the number of deaths linked to obesity, twice as many were linked to lack of physical activity - and, moreover - just a modest increase in physical activity could make a difference, especially among inactive people.

The researchers at the Medical Research Council (MRC) Epidemiology Unit at the University of Cambridge in the UK, and colleagues report their findings in the American Journal of Clinical Nutrition.

This particular study delivers a simple message: "just a small amount of physical activity each day could have substantial health benefits for people who are physically inactive."

Biggest effect was between inactive and moderately inactive groups

To assess the link between lack of exercise and early death - and how it might relate to this via obesity - the team analyzed data on 334,161 men and women across Europe taken between 1992 and 2000 as part of the European Prospective Investigation into Cancer and Nutrition (EPIC) Study.

The dataset included measures of height, weight, waist size and self-reported physical activity levels. The participants were followed for over 12 years, during which time 21,438 of them died.

The research team found the greatest reductions in risk of early death when they compared inactive and moderately active participants. They used a measure of physical activity derived from combining leisure and at work activity.

The links between early death and physical inactivity were observed across all levels of overweight and obesity measures - both in terms of overall BMI and central or abdominal obesity.

The study classed 22.7% of participants as inactive because they reported having no recreational activity and were occupied in sedentary jobs.

The analysis found that doing exercise that burned just 90-110 calories a day - the equivalent of a daily 20-minute brisk walk - was enough to move an individual from the inactive to the moderately inactive group and reduce their risk of early death by 16-30%.

The research team notes that while the effect of this was greatest among participants of normal weight, the analysis showed this also benefited overweight and obese participants.

We should do more than 20 minutes a day

However, the researchers note that while 20 minutes of brisk walking a day can make a difference, we should really do more, as "physical activity has many proven health benefits and should be an important part of our daily life."

In fact, while we need to continue with public health efforts that reduce levels of obesity, we should also be helping people increase physical activity. This might be easier to achieve and maintain, and can have significant health benefits.

The traditional view of exercise need not limit our intention to become more physically active. In addition, yoga is comparable to walking and biking in reducing risks of cardiovascular disease.

References:

1.     Physical activity and all-cause mortality across levels of overall and abdominal adiposity in European men and women: the European Prospective Investigation into Cancer and Nutrition Study (EPIC), Ulf Ekelund, et al., Am J Clin Nutr, doi:10.3945/​ajcn.114.100065, published online 14 January 2015, abstract.

2.     Cambridge University news release, accessed 15 January 2015.