Let's start with the fact that American office workers don't move much. They sit on average anywhere from 7 to 13 hours a day, depending on which stat you read. The habit could be elevating our risk of mortality, obesity, and, of course, heart disease—the number one killer of Americans—according to the Cochrane group.
Indeed, the people in America are living much different lives than we were even a few hundred years ago. To find out how our modern, sedentary lifestyles have affected our heart health, scientists studied a completely unmodern group: Hadza hunter-gatherers in Tanzania. The tribe members wore wear heart rate monitors for two weeks, a way to determine their activity levels. The result: The Hadza move about 14 times more than the average American. In fact, they log about 138 daily minutes of moderate-intensity activity, such as walking at a quick pace, or lifting and carrying things.
The scientists found that the tribe members' tickers were all Swiss watches. Even the oldest among them displayed excellent markers of heart health.
Does this mean we could solve the American heart crisis if we just had everyone increase their activity 14-fold? No. First of all, that wouldn't be practical. Second, the study had a large confounding variable: the tribe's diet. The Hadza people subsist on hunted meats, fruits, tubers, and honey (read: not Doritos, Chalupas, Milky Ways, and Pepsi).
And studies on Australian workers suggest diet might play a larger roll compared to movement. Blue collar workers from Down Under each day sit just 1.6 hours and take 11,784 steps—roughly 5.5 to 6.5 miles of walking—according to researchers at the University of Queensland. If you assume it takes most people 15 minutes to walk a brisk (moderate intensity) mile, that's 82.5 to 97.5 minutes of exercise. Not quite Hadza level, but it still puts these workers anywhere from 3.85 to 4.55 times above the CDC recommendation of logging 150 weekly minutes of moderate exercise.
Australian white collar workers, on the other hand, sit about 6.2 hours and take just 7,883 steps each day. But does that relative lack of physical activity affect their heart heath more? Maybe not, according to this study. Here's the data:
As you can see, Aussie blue collar workers die from heart disease at about double the rate of white collar workers. What's going on here? Studies suggest blue collar workers consume lower-quality diets and are more likely to smoke.
Americans are smoking less, so is diet is the cure-all? Probably not. Most Americans will never eat a "perfect" diet. And among people of the same socio-economic status, more moderate and vigorous physical activity has a clear association with living longer.
So what does the Hadza study tell us? That heart health is determined by a variety of lifestyle factors. We're moving far less at eating differently than we used to, and that "old way"—the Hadza way—seems to be better for our hearts. So move more (walking counts!), and try to follow the CDC's diet guidelines. Don't try to make those changes all at once, which experts say only sets you up for failure. Here's a painless, sustainable way to overhaul your lifestyle.