Standing good for heart health
Spending too much time sitting cannot be good for the body, and rising to one's feet breaks up such a behaviour and yields small, but meaningful, reductions in certain cardiovascular disease (CVD) risk factors, according to the results of a meta-analysis.
“[R]eplacing an average of 1.33 hours of sitting per day with standing for an average of 4 months can modestly decrease fasting blood glucose (FBG) and body fat mass (BFM) values,” the investigators said.
They pointed out that the effects may have to do with energy expenditure and muscle contraction. Theoretically, standing can cut BFM over time, as the activity “expends significantly more energy (0.15 kcal/min) than sitting, and standing for 6 hours per day for a year could have a significant effect on energy expenditure.” [Eur J Prev Cardiol 2018;25:522-538]
Meanwhile, muscle contraction helps in the regulation of blood glucose, the investigators continued. “Standing involves more muscles than sitting, and this can be a physiologic explanation for the [decrease in FBG].” [PloS One 2013;8:e52228]
The investigators pooled data from nine clinical trials evaluating the effect of replacing sitting time with standing for at least 30 minutes per day in comparison with sitting without any significant break. There were 877 participants (mean age, 45.34 years; 64.4 percent female) in total. The mean follow-up was 3.81 months.
Standing time in the intervention group was longer by 1.33 hours per day than in the control group. Furthermore, FBG was lower by 2.53 mg/dL (95 percent confidence interval [CI], −4.27 to −0.79) and BFM by 0.75 kg (95 percent CI, −0.91 to −0.59) in the intervention group. [Mayo Clin Proc Innov Qual Outcomes 2020;4:611-626]
The analysis for fasting insulin concentration, lipid levels, blood pressure, weight, and waist circumference revealed no significant differences.
In essence, replacing sitting with standing can be used only as an adjunctive intervention to decrease the burden of CVD risk factors but not as an alternative to physical activity to offset the bad from lengthy sedentary time, the investigators explained.
They cautioned against generalizing the results of the study to people from different cultures and with different extents of dysregulation in CVD risk factors, given that all participants of the included studies were healthy and from Denmark and Australia. Also, the intensity and duration of the intervention, as well as length of follow-up, might not have been enough to make a significant change in the endpoint.
In future studies, the investigators urged evaluating both the financial and clinical impact of the intervention in different groups of participants.
“In the meantime, until further prospective and experimental evidence proves [the] beneficial effects of standing vs sitting on measures of cardiometabolic regulation or outcomes, the strategies to decrease sedentary time need to include physical activity,” they said.