乌鸦传媒

Exercising in the morning lowers blood pressure (BP) for a good portion of the day among older adults who are obese or overweight, especially women, a randomized crossover study found.

Compared with uninterrupted sitting among sedentary individuals, half an hour of moderate-intensity walking in the morning reduced the average 8-hour blood pressure by 3.4/0.8 mm Hg.

For the exercise and breaks condition, the 8-hour average systolic and diastolic went up to a 5.1 and 1.1-mm Hg decline, respectively, reported Michael Wheeler, BSc, of Baker Heart Institute in Australia, and colleagues in .

Adding 3 minute light walking breaks every half hour after the morning walk further reduced systolic blood pressure by 1.7 mm Hg (P=0.003), which was driven by an average 3.2 mm Hg reduction among women.

The other key sex difference was that mean epinephrine increased with exercise and sitting as well as the exercise and breaks group for men (+12% to +23%) but declined among women (-13% to -12%) compared with sitting alone. There were no differences in average norepinephrine reported.

Long-term investigations are warranted to confirm these results, as "this line of evidence may inform clinical and public health discussions around tailored strategies to optimize BP targets in older adults with increased cardiovascular disease risk," the researchers wrote.

Other studies have shown that adding intermittent light activity to an otherwise sedentary lifestyle helps blood pressure, the researchers noted.

"Participants included in such trials which investigate exercise training tend to have a lower starting blood pressure than those included in trials testing antihypertensive medication. As the majority of participants in our study did not have hypertension, we see this result as promising from the perspective of prevention. However, it would be interesting to do a similar study in the future and include only participants with hypertension to see if the reductions in blood pressure would be larger," Wheeler told 乌鸦传媒.

Wheeler's group evaluated 67 sedentary participants with an average body mass index of 31.2 kg/m²and a mean age of 67.

Participants were assigned to each of the following in random order:

• Exercise and breaks: sitting for 1 hour, moderate-intensity walking for 30 minutes, and then sitting interrupted every 30 minutes with 3 minutes of light-paced walking for 6.5 hours.
• Uninterrupted sitting for 8 hours
• Exercise and sitting: sitting for 1 hour, moderate walking for 30 minutes, and then uninterrupted sitting for 6.5 hours

The main limitation was lack of a group that only took breaks in sitting without more extensive exercise, Wheeler said.

"This was intentional, because we considered the evidence that an acute 30-minute bout of exercise impacts BP responses to be strong, and there are a number of studies that support the BP-lowering effect of active breaks compared with uninterrupted sitting alone," he said. "We wanted to know whether the addition of active breaks to an exercise bout enhanced the BP benefit.

"In light of our finding it will be important for future studies to investigate sex differences in the BP response to breaks in sitting alone," Wheeler added.