BACKGROUND: 
 
 The relationship between metabolic risk and time spent sitting, standing and stepping has not been well established. The present study aimed to determine associations of objectively measured time spent siting, standing and stepping, with coronary heart disease (CHD) risk. 
 
 METHODS: 
 
 A cross-sectional study of healthy non-smoking Glasgow postal workers, n=111 (55 office workers, 5 women, and 56 walking/delivery workers, 10 women), who wore activPAL physical activity monitors for 7 days. Cardiovascular risks were assessed by metabolic syndrome categorisation and 10-year PROCAM (prospective cardiovascular Munster) risk. 
 
 RESULTS: 
 
 Mean (s.d.) age was 40 (8) years, body mass index 26.9 (3.9) kg m-2 and waist circumference 95.4 (11.9) cm. Mean (s.d.) high-density lipoprotein cholesterol (HDL cholesterol) 1.33 (0.31), low-density lipoprotein cholesterol 3.11 (0.87), triglycerides 1.23 (0.64) mmol l-1 and 10-year PROCAM risk 1.8 (1.7)%. The participants spent mean (s.d.) 9.1 (1.8) h per day sedentary, 7.6 (1.2) h per day sleeping, 3.9 (1.1) h per day standing and 3.3 (0.9) h per day stepping, accumulating 14 708 (4984) steps per day in 61 (25) sit-to-stand transitions per day. In univariate regressions-adjusting for age, sex, family history of CHD, shift worked, job type and socioeconomic status-waist circumference (P=0.005), fasting triglycerides (P=0.002), HDL cholesterol (P=0.001) and PROCAM risk (P=0.047) were detrimentally associated with sedentary time. These associations remained significant after further adjustment for sleep, standing and stepping in stepwise regression models. However, after further adjustment for waist circumference, the associations were not significant. Compared with those without the metabolic syndrome, participants with the metabolic syndrome were significantly less active-fewer steps, shorter stepping duration and longer time sitting. Those with no metabolic syndrome features walked >15 000 steps per day or spent >7 h per day upright. 
 
 CONCLUSIONS: 
 
 Longer time spent in sedentary posture is significantly associated with higher CHD risk and larger waist circumference. 

 So for the new study, which was published this month in The International Journal of Obesity, researchers at the University of Warwick in England and other institutions decided to refer back to but also advance and expand upon the results of that foundational Transit Workers Study by examining another group of employees whose workdays involve mostly walking or sitting. They turned to postal workers in Glasgow, Scotland. 
 
 The Glaswegian mail carriers generally cover their routes on foot, not by driving, and spend many hours each day walking, the scientists knew. But the mail service’s office workers, like office workers almost everywhere, remain seated at their desks during the bulk of the workday. 
 
 This sharp contrast between the extent to which the workers move or sit during the day could provide new insights into the links between activity and health, the scientists felt. 
 
 They began by recruiting 111 of the postal-service workers, both men and women, and most between the ages of 40 and 60. None had a personal history of heart disease, although some had close relatives with the condition. 
 
 The researchers measured volunteers’ body mass indexes, waist sizes, blood sugar levels and cholesterol profiles, each of which, if above normal, increases the chances of cardiac disease. 
 
 Then they had each volunteer wear a sophisticated activity tracker for a week, while at work and at home and during the weekend. 
 
 Afterward, the researchers determined how many waking hours each day the volunteers had spent seated or on foot. They also calculated how many steps each person had taken each day. 
 
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 The variations turned out to be considerable. Some of the office workers sat for more than 15 hours each day between work and home, while most of the mail carriers barely sat at all during working hours. 
 
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 These differences were echoed in the volunteers’ risk factors for heart disease, the researchers found. Those workers who sat for most of each day tended to have much larger waistlines, higher B.M.I.’s and worse blood sugar control and cholesterol profiles than those who frequently stood and moved, even after scientists controlled for age, family history, late-night shift work (which is known to affect heart health) and other factors. 
 
 The risks were magnified at the extremes. For every hour beyond five that workers sat each day, the researchers found, they added about two-tenths of a percentage point to their likelihood of developing heart disease, based on their cumulative risk factors. 
 
 Meanwhile, almost any amount of standing and walking reduced a worker’s chances of having a large waistline and other risk factors for heart disease. 
 
 But the greatest benefits came from the most exaggerated amounts of activity. Those mail carriers who walked for more than three hours a day, covering at least 15,000 steps, which is about seven miles, generally had normal body mass indexes, waistlines and metabolic profiles. Together, these factors meant that they had, effectively, no heightened risk for cardiac disease. 
 
 Of course, this study provides a single, limited snapshot of people’s health and lives. The researchers did not follow their volunteers for decades to see who actually developed heart disease. This kind of study also cannot prove that walking or sitting caused the differences in people’s risks factors for heart disease, only that there were associations between activity and risks. 
 
 But the findings do imply that there are good reasons to get up from our desk chairs and move, even more than many of us may already be trying to do, said Dr. William Tigbe, a physician and public health researcher at the University of Warwick who led the study. 
 
 “It takes effort,” he said, but we can accumulate 15,000 steps a day by walking briskly for two hours at about a four-mile-per-hour pace, he said. 
 
 “This can be done in bits,” he adds, perhaps with a 30-minute walk before work, another at lunch, and multiple 10-minute bouts throughout the day. 
 
 “Our metabolism is not well-suited to sitting down all the time,” he concluded.
– Feeling smug when you clock 10,000 steps each day? Not so fast: While that target has widely been hailed as a goal to beat cardiovascular disease, a new study suggests upping it to 15,000 steps. UK researchers who studied 111 postal workers in Glasgow found profound differences in the health markers for those who were on their feet the longest each day, the New York Times reports. Some of the workers, who were mostly aged 40 to 60, sat for 15 hours or more daily at office jobs and at home, and others were mail carriers who walked their routes. The volunteers wore an activity monitor for a week, at work and off duty, that measured how many steps each took and how much time they spent seated. Writing in the International Journal of Obesity, the scientists reported that those who walked at least 15,000 steps each day, or about seven miles, showed no increased risk of heart disease. Those who moved the most had normal waistlines and BMIs, but any amount of walking or even standing shrank a worker's waistline and risk of cardiovascular disease. For the sedentary workers, the picture was the opposite. After five hours of sitting a day, each additional hour in the chair boosted their chance of developing heart disease by .2%. The results highlight the importance of moving around—a lot. For 15,000 steps, that means walking for two hours at a very brisk pace of 4mph, lead author Dr. William Tigbe tells the Times. He suggests tackling that target "in bits" by doing 30-minute walks a couple of times a day, with shorter walks in between. "Our metabolism," he says, "is not well-suited to sitting down all the time." (There's a new daily recommendation for fruits and veggies.)