Swimming lowers older adults’ blood pressure
Many older adults like to take a dip a pool, and now a small study suggests it can be good for their blood pressure.
Researchers found that among 43 older men and women, those who started swimming a few times a week lowered their systolic blood pressure – the “top” number in a blood pressure reading.
On average, the swimmers started the study with a systolic blood pressure of 131 millimeters of mercury (mm Hg). Three months later, it was 122 mm Hg.
Normal blood pressure is defined as an average reading no higher than 120/80 mm Hg. Readings of 140/90 or higher are considered high blood pressure, and anything in between is considered “pre-hypertension.”
Swimming is often promoted as a good way for older people to exercise, since it’s easy on the joints and it’s not likely to cause overheating. And many follow that advice: after walking, swimming is the second-most popular form of exercise among the older set.
But there’s been little research into the health benefits of swimming – though a number of studies have suggested that it’s as safe for older adults as walking and bicycling, said Hirofumi Tanaka, senior researcher on the new study.
Published in the American Journal of Cardiology, the research appears to be the first to demonstrate that swimming can improve older adults’ blood vessel function and curb their blood pressure.
“Swimming is a very attractive form of exercise,” Tanaka, a researcher at the University of Texas at Austin, told Reuters Health in an email.
“It’s easily accessible and inexpensive,” Tanaka noted. “And because it does not involve bearing of body weight, due to the buoyancy of water, it is friendly to knee and ankle joints.”
The study included 43 adults, with an average age of 60, who had high blood pressure or pre-hypertension but were otherwise healthy.
The researchers randomly assigned them to either have supervised swimming sessions or learn relaxation exercises. Over 12 weeks, the swimmers got in the pool three or four times a week, gradually working their way up to 45 minutes of swimming at a time.
By the end of the study, the swimmers had shaved an average of nine points from their systolic blood pressure. In contrast, that number did not budge in the relaxation group.
The picture was similar when the researchers had the study participants wear portable monitors that tracked their blood pressure over 24 hours. On average, the swimming group had a 24-hour systolic blood pressure of 119 mm Hg – down from 128 mm Hg at the study’s start.
Tanaka’s team also used ultrasound tests to measure how well participants’ blood vessels were dilating in response to blood flow. Again, they found improvements in the swimming group, but not in the relaxation group.
The study was small, and it’s not clear whether the blood pressure reduction lasts – or whether it translates into a lower risk of heart attack or stroke down the line.
In a healthy body, blood flows through arteries that are flexible and soft. As your blood flows through, the walls of an artery are under pressure. The amount of pressure on your artery walls is your blood pressure. FamilyDoctor.org reports that high blood pressure, or hypertension, can cause stroke, heart attack, kidney failure and heart disease. Swimming is an efficient way to lower high blood pressure, but contact your doctor before starting a new exercise program.
Swimming for a Stronger Heart
According to MayoClinic.com, exercise such as swimming can help reduce your blood pressure with as much effectiveness as a blood pressure medication. Aerobic exercise strengthens the heart, allowing more blood to flow through unencumbered. Swim at least 30 minutes a day to reap the most benefits while simultaneously lowering your blood pressure.
But the results line up with what experts already recommend for older adults’ heart health: get regular moderate exercise, along with a healthy diet.
Tanaka said that as long as an older adult has gotten the OK to exercise moderately, swimming should be a safe activity. But if you’re sedentary, check with your doctor before becoming newly active.
A study conducted at the University of Tennessee investigated the effects of swimming in 18 people with mild hypertension. Twelve were put in the swimming training group, and the other six served as controls, who did not start any exercise program. The training consisted of swimming for 45 minutes on three days a week for 10 weeks, at a target heart rate of 60% of the maximum. The average distance swum during each session increased from 880 meters at the start of training to 1590 meters at the end.
The resting blood pressure decreased in 11 of the 12 subjects who completed the training program, the average decrease being 7mm Hg in systolic and 3 mm Hg in diastolic pressure. No changes occurred in the control group. Heart rate decreased by six beats a minute. Many of the subjects were somewhat overweight, but no changes in weight occurred during the study.
There was a time when swimming was considered potentially risky, Tanaka noted, because being in cold water “elicits cardiovascular changes.”
But most studies have indicated that bobbing in the waters of your local pool would be as safe as a walk around the neighborhood.
SOURCE: American Journal of Cardiology, online January 16, 2012