If you are among the millions of people who work at a desk job and don't exercise, a 20-minute walk each day can do wonders for your health. That is one of the findings of a 10-nation study that tracked over 300,000 people for 12 years. The study suggests that getting this small amount of activity boosts the odds of living longer even more than slimming down does.
If good health habits were easy, everyone would be healthy. But between the temptations that lead people into bad habits, and the fact that so many of us spend most of our time sitting in a chair or on the couch, it's not surprising that many people develop a weight problem before they even know it.
Studies have shown that both a lack of exercise and overeating are bad for your health, but it has been difficult to determine which will make you healthier: losing some weight or becoming more active.
The 10-nation study clearly comes down on the side of becoming more active. The more inactive you are, the more you stand to gain by increasing your activity.
The small increase in activity that moved a person from inactive to moderately inactive resulted in a 16-30% drop in mortality risk. The researchers estimate that one brisk 20-minute walk per day is all that people who are inactive need to do to achieve this.
The data were drawn from the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Everyone for whom weight, height, waist circumference and physical activity data were available (334,161 people) was included in the study. They were followed for an average of 12.4 years; their deaths were also tracked.
Based on their activity at work and during leisure time, people in the study were divided into four activity classes: inactive, moderately inactive, moderately active and active.
Researchers looked most closely at how physical activity changed the mortality risk of people who were obese, overweight, and of normal weight; they also analyzed activity in relation to normal and large waist size.
The greatest jump in longevity was seen between the two groups at the low end of the range of activity — between those people who were essentially inactive and those who were slightly higher in activity, the moderately inactive.
The small increase in activity that moved a person from inactive to moderately inactive resulted in a 16-30% drop in mortality risk. The researchers estimate that one brisk 20-minute walk per day would achieve this for people who are inactive. This is about the amount of activity needed to burn 90 to 110 calories. Twenty minutes a day is less time than some phone calls take.
Raising activity a bit more (to the moderately active class) decreased mortality risk by up to 41% in individuals who were normal weight or overweight.
The researchers also estimated that eliminating inactivity would prevent about twice as many deaths as eliminating obesity would. This isn't a license to overeat, but it does suggest that if you are not active, becoming more active is a better first step toward being healthier than cutting calories. Naturally, success at both would be healthiest.
As Nick Wareham, one of the authors, said in a statement, “Helping people to lose weight can be a real challenge, and whilst we should continue to aim at reducing population levels of obesity, public health interventions that encourage people to make small but achievable changes in physical activity can have significant health benefits and may be easier to achieve and maintain.”
The study appears in the American Journal of Clinical Nutrition and is freely available.