A NEW paper published in the Lancet on July 18th, timed to coincide with the Olympics, compares countries’ rates of physical activity. The study it describes, led by Pedro Hallal of the Federal University of Pelotas, is the most complete portrait yet of the world’s busy bees and couch potatoes. Dr Hallal and his colleagues pooled data from health surveys for 122 countries, home to 89% of the world’s population. They found that 31% of adults do not get enough physical activity—defined as 30 minutes of moderate exercise five days a week, or 20 minutes of vigorous exercise three days a week, or some combination of the two. Women tend to get less exercise—34% are inactive, compared with 28% of men—but there are exceptions and regional variations, as the maps below show. Women in Russia, Croatia, Luxembourg, Greece and Iraq (to name a few) move more than their male counterparts. Malta wins the race for the most slothful nation, with 72% of adults getting too little exercise. Swaziland and Saudi Arabia slouch close behind, with 69%. In Bangladesh, by contrast, just 5% of adults fail to get enough exercise. Surprisingly, America does not live up to its sluggish reputation. Six in ten Americans are sufficiently active, compared with less than four in ten Britons. These figures are worrying. According to another paper in the Lancet,insufficient activity has about the same effect on life expectancy as smoking.