MUNICH — “No thanks, I'll take the stairs instead.”
This was the cry that rang through the corridors of University Hospital, Geneva, last year as physicians and nurses participating in the Geneva stair study eschewed elevators in favor of foot power.
The study was set up to test a population-based strategy for increasing physical activity that's designed to be easy to incorporate into everyday life—namely, taking the stairs instead of elevators in the workplace, where most adults spend half their waking hours, Dr. Philippe Meyer explained at the annual congress of the European Society of Cardiology.
The payoff from the 3-month intervention was significant reductions in waist circumference, body weight, fat mass, diastolic blood pressure, and LDL cholesterol. These changes were accompanied by increased aerobic capacity as measured by maximum oxygen uptake, or VO2 max, reported Dr. Meyer of the University of Geneva.
The need to develop novel approaches aimed at increasing physical activity in the broad population arises from surveys indicating that fewer than half of Europeans and Americans meet current public health guidelines recommending a minimum of 30 minutes of moderate-intensity aerobic activity 5 days per week. Meanwhile, rates of obesity, dyslipidemia, and diabetes continue to climb.
The Geneva stair study included 77 physicians and nurses with a sedentary lifestyle, defined as less than 2 hours of exercise per week and less than 10 flights of stairs covered per day. The participants were asked to use stairs exclusively instead of elevators at work for 12 weeks. The hospital building is 12 stories; most study participants worked on the first 7 floors. Participants wore badges with a staircase diary printed on the back.
The 42 women and 35 men in the study averaged 43 years of age, with a mean body mass index of 25.7 kg/m
The participants' combined daily ascent and descent of stairs jumped from a mean of 5.1 floors at baseline to 22.7 floors daily. Over the course of 12 weeks, the 69 subjects who completed the study experienced a significant reduction in waist circumference, from a mean of 87.9 cm to 86.4 cm. Their mean weight dropped from 74.4 kg to 73.9 kg; this included a 350-g mean reduction in body fat.
Particularly impressive was the participants' gain in aerobic capacity: Mean VO2 max rose from 37.3 mL/kg per minute to 40.5 mL/kg per minute, an 8.6% increase. This corresponds to a gain of nearly 1 metabolic equivalent. When maintained long-term, an increase of this magnitude has been shown to confer a 14%-15% reduction in all-cause mortality, Dr. Meyer noted.
In addition, participants experienced a mean 1.8-mm Hg decrease in diastolic blood pressure, a 3.9% reduction in LDL level, and favorable but nonsignificant trends with regard to systolic blood pressure, triglycerides, and HDL cholesterol.
“At the population level, all this could lead to significant cardiovascular preventive effects,” he observed.
At 6 months' follow-up—3 months after the intervention's end—the mean number of floors of stairs covered daily had declined to 10. The only benefits at 3 months that remained statistically significant at 6 months were the gain in aerobic capacity—VO2 max was still 5.6% improved over baseline—and the reduction in fat mass. However, the somewhat disappointing 6-month data are misleading because right after the end of the 12-week intervention the building's main staircase was closed for renovation. “We didn't know that was coming. Many people no longer used the stairs. It affected the 6-month results,” Dr. Meyer said.
He noted that a major study limitation was the lack of a control group. Asked how he'd go about designing a large confirmatory, randomized, controlled trial, Dr. Meyer said he'd recruit multiple businesses located in separate buildings. “You cannot choose a control group in the same environment because the control group will be contaminated by the promotional campaign that you do,” he said, explaining that as part of the campaign, posters urging people to take the stairs had been placed in the building at points of choice.
ELSEVIER GLOBAL MEDICAL NEWS
ELSEVIER GLOBAL MEDICAL NEWS