September 14, 2016
Are you a fidgeter?
From now on, you can ignore the frequent requests you undoubtedly receive to just sit still. A new study finds that fidgeting — the toe-tapping, foot-wagging and other body movements that annoy your co-workers — is in fact good for your health.
Sitting is one of the scourges of modern life. We sit during meetings, automobile and airplane trips, while completing lengthy work assignments and while binge-watching “Stranger Things.” Studies of movement patterns indicate that most of us spend between eight and 10 hours each day seated. During that time, our bodies and, in particular, our legs barely move.
The health consequences of this muscular immobility are well documented and include an increased risk for weight gain, as well as diabetes, since unused muscles in the legs do not pull sugar from the blood, leading to a dangerous rise in blood sugar.
But the most immediate impact of oversitting is on our vasculature. Studies show that uninterrupted sitting causes an abrupt and significant decline in blood flow to the legs. This is problematic since, when blood flow drops, friction along the vessel walls also declines. The cells that line these walls, which can sense changes in the friction, begin to pump out proteins that contribute over time to hardening and narrowing of the arteries. This may make biological sense, because arteries don’t need to be as flexible when there isn’t much blood in them, but when the blood flow increases, the blood vessel remains stiff, increasing blood pressure and raising the risk for atherosclerosis.
We can combat that situation easily by standing up and moving, causing leg muscles to contract and blood flow to remain steady.
“But there are many situations in which people cannot just stand up,” such as during long meetings or car trips, said Jaume Padilla, an assistant professor of nutrition and exercise physiology at the University of Missouri in Columbia, who led the new study.
So Dr. Padilla and his colleagues began to consider other, relatively unobtrusive and practical ways that someone might combat the decline in blood flow associated with sitting.
For the new study, which was published in July in The American Journal of Physiology Heart and Circulatory Physiology, they hit upon fidgeting.
Dr. Padilla and his colleagues thought it was conceivable that lower-body fidgeting might also result in enough muscular activity to elevate blood flow to the legs.
To test that possibility, they recruited 11 healthy college students and, using ultrasound and a blood pressure cuff, first measured the level of normal blood flow through one of the main arteries in their legs and determined how well that artery responded to changes in blood pressure — a marker of arterial health.
Then they asked each subject to sit for three hours in front of a desk. The volunteers could study, work on their computers, talk on the phone or otherwise amuse themselves but, for those three hours, were not allowed to rise.
Most importantly, they asked the volunteers to keep one leg perfectly still, the foot flat against the floor and unmoving. With the other leg, the volunteers were told to fidget — tapping their heels against the ground for one minute and then staying still for four minutes. (A clock chimed to let them know when to start or stop fidgeting.)
Over the course of the three hours, the researchers monitored the blood flow in the volunteers’ leg arteries.
The blood flow in the unmoving leg declined precipitously, but it rose in the fidgeting leg, compared both to baseline levels and to the unmoving leg.
More striking, at the end of the three hours, when the researchers again tested the ability of the volunteers’ arteries to respond to changes in blood pressure, the vessel in the unmoving leg no longer worked as well as it had during baseline testing, which suggests it was already not as healthy as it had been.
But the artery in the volunteers’ fidgeting leg responded as well as or better than it had at baseline to changes in blood pressure.
“To be honest, we were surprised by the magnitude of the difference” between the two legs, Dr. Padilla said.
“We had expected that fidgeting might attenuate” the reduction in blood flow and any subsequent acute changes in vessel health, he said, but the differences in terms of blood flow and subsequent arterial function were much more significant than they had anticipated.
“The muscular contractions associated with fidgeting are really quite small,” he said, “but it appears that they are sufficient” to combat some of the unhealthy consequences of sitting.
Of course, the study was small, short term and involved only healthy young people. It also did not retest the volunteers’ vascular function after they had risen and begun to move around normally. Dr. Padilla said he thought it was likely that any undesirable consequences from this single session of not moving would soon disappear.
But repeated bouts of muscular stillness could over time cause such impacts to become permanent, he said.
So if you can’t rise and walk around during your next lengthy meeting, he said, tap your toes. Bob your feet. Keep your legs in motion somehow, no matter how slight. And if your spouse or aisle mate should frown in annoyance, point out that science now says that fidgeting is good medicine.