At the end of 2011, Rita Tretter set out to lose weight, and at first she did. Without changing her diet, she dropped 17 pounds in three months by taking a one-hour power walk every day. But at 152 pounds she hit a plateau—and then started to gain. So in April 2012 she changed her strategy: She added running intervals to her morning walks and began to build other mini bursts of movement into her life. A St. Paul, Minnesota, medical biller who works at home, Tretter typically spent 70 to 80 hours a week sitting at her desk. For her new regimen, she paced her house for a few minutes every hour, bounced in her chair while studying a spreadsheet and replaced her 2 pm coffee-and-chocolate break with a leisurely 15-minute walk outdoors. She found other means to be active as well. “I changed the way I do pretty much everything,” she says. Four months later, she’s 133 pounds, her weight at age 35.
Tretter’s behavior changes raised her level of what Mayo Clinic researcher James Levine has dubbed NEAT, or non-exercise activity thermogenesis. Basically, NEAT is all the movement you engage in that isn’t actually -exercise—so while Tretter’s morning run counts as a workout, all her other changes fall into the NEAT category. In this way, Levine says, the average person can boost her daily energy expenditure by 350 calories. “Just getting off your bottom and standing up requires so much muscular activity that your metabolism spikes immediately,” says Levine. Tretter’s new strategy was inspired by a compact-size gadget called the Gruve Personal Activity Monitor (gruve.com), which was specifically created to keep track of NEAT. The device counts the calories you burn throughout the day, and as the number rises, the Gruve changes color from red to orange to yellow to blue to—yay!—green. You can customize it with your own target: For example, to lose one pound a week, you have to burn roughly 3,500 calories a week, or 500 a day. Sit too long at your desk, and the device vibrates, reminding you to get moving. “Sometimes I hit green by 2 o’clock, but sometimes it’s 7:30 at night and I’m not at green yet, so I’ll take the dogs for an extra walk,” Tretter says. She isn’t the only one surprised, and heartened, by how effective mini bursts of exercise can be. In a new study, a team of researchers from the University of Copenhagen found that participants who worked out at moderate intensity for 30 minutes a day actually lost more weight than those who worked out vigorously for 60 minutes a day. In 13 weeks, the hour-a-day exercisers dropped five pounds, whereas those who exercised half as long dropped seven. Why? The study suggests that the latter group was deliberately more active throughout the day. “When people work out for an hour, consciously or not they tell themselves, Great, now I can sit on my butt the rest of the day,” says Mark Blegen, PhD, a researcher on the effectiveness of exercise on metabolism at St. Catherine University in St. Paul, Minnesota.
Also lifting Tretter’s metabolism: She has started sleeping through the night for the first time in decades. The reason that helps, says David Katz, MD, director of Yale University Prevention Research Center, is that when you’re sleep deprived, your hormones go haywire, leading to surging levels of insulin and cortisol, which in turn contribute to the accumulation of body fat. Furthermore, getting less than six hours’ sleep for just a couple of nights pumps up the hormone ghrelin, which tells us we’re hungry, and causes a slump in leptin, the satiety hormone that promotes sensations of fullness. “I feel younger than I did at 40,” Tretter says. “At 35, before my daughter was born, I felt perfect—slim and curvy—and I feel pretty much the same way now.”
Kelly Boyer's Secret: Frequent Meals
Used to weigh: 137 lb.
Now weights: 109 lb.