MoMo Productions/Getty ImagesMichael Tschakovsky, an associate professor in the School of Kinesiology and Health Studies at Queen’s University in Kingston, Ontario, enjoys a post-exercise massage as much as anyone. But unlike those of us who happily drowse through the massage therapist’s assurance that the pummeling and kneading is speeding blood flow to our muscles and draining them of built-up lactic acid, Mr. Tschakovsky took notes. His academic specialty is the study of blood flow to muscles, particularly in diseases like diabetes, and he decided to put the therapists’ words to the test.
Recruiting 12 healthy young men, he and his colleagues had them exercise their forearm muscle to exhaustion. The men accomplished this by squeezing a specialized handgrip at 40 percent of maximum force for two minutes, nonstop. “If that doesn’t sound hard, try it,” Mr. Tschakovsky says. By the end of the two minutes, the men’s arms shook with fatigue. Their hearts beat faster, and lactic acid, measured by a catheter inserted directly into the deep vein that drains the muscle, enveloped the straining forearm muscle.
Lactic acid is widely believed by many of us outside academia to cause muscle fatigue and soreness after exercise. Physiologists are more skeptical. Recent studies have found few negative effects from lactic acid and, in fact, have shown that it provides fuel for tired muscles. But the studies are not definitive, so “it’s still theoretically possible” that lactic acid has some impact on fatigue, Mr. Tschakovsky says, especially in events that involve repeated short bouts of intense exercise. More to the point, “most people think that one of the main benefits of massage is that it removes lactic acid,” he says, whether such dispersal is important or not. “We wanted to see if massage fulfills” that promise.
So after the volunteers had exhausted their arms and pumped them full of lactic acid, they either lay quietly for 10 minutes (passive recovery), intermittently squeezed a handgrip at about10 percent of their maximum strength for the same 10 minutes (active recovery) or had their arm massaged by a certified sports-massage therapist for 10 undoubtedly pleasurable minutes. Throughout, blood flow to the forearm muscle of the volunteers was measured by ultrasound, while their lactic acid concentrations were monitored via blood samples.
The results, published in the latest issue of the journal Medicine & Science in Sports & Exercise, are a blow, at least to those of us who justify our massages as medicinal. It turned out that massage did not increase blood flow to the tired muscle; it reduced it. Every stroke, whether long and slow or deep and kneading, cut off blood flow to the forearm muscle. Although the flow returned to normal between strokes, the net effect was to lessen the amount of blood that reached the muscle, particularly compared with the amount that flowed to the forearm muscle during 10 minutes of passive recovery. Meanwhile, active recovery reduced blood flow as well, since muscular contractions, however slight, compress blood vessels in the muscle briefly. But the overall reduction of blood flow was significantly less during active recovery than during the massage session.
As a “direct result” of the lessened blood flow to their muscles, Mr. Tschakovsky says, the volunteers being massaged wound up with far less lactic acid removal than the groups who recovered passively or actively. Massage “actually impairs removal of lactic acid from exercised muscle,” Mr. Tschakovsky and his colleagues wrote in their published study.
Although the findings may seem counterintuitive (and, frankly, depressing), they actually are in agreement with a growing body of science about sports massage. Multiple other recent studies have found that massage tends to impede rather than improve blood flow to tired muscles. Mr. Tschakovsky’s experiment, however, directly correlates that impact with lactic-acid removal in the affected muscle.
Do his and the other scientists’ results mean that massage is worthless after exercise? “Not at all,” Mr. Tschakovsky says. “This experiment had a specific aim, to see whether massage improved blood flow and lactic-acid removal in an exercised muscle. It did not. That does not mean massage doesn’t have other beneficial effects. We just don’t necessarily know what they are yet.”
M. K. Brennan, a licensed massage and bodywork therapist registered nurse and former president of the American Massage Therapy Association, is more blunt. “Too many knowledgeable, experienced athletes rely on massage for there not to be a significant benefit,” she says. The psychological effects, for instance, may be extensive and pervasive, she says. A number of recent experiments have found that sports massage may reduce post-exercise blood concentrations of cortisol, a hormone associated with stress. In a particularly apropos study from 2000 of boxers, inter-bout massages left the athletes feeling significantly more recovered. The athletes didn’t subsequently punch any harder in their second bouts after a massage than after passive rest, but they felt less tired.
“The main takeaway” of Mr. Tschakovsky’s study, Ms. Brennan says, “is that far more research about exercise and sports massage is needed.”
Mr. Tschakovsky agrees. “Our study does not mean people should skip massages,” he says. “I’m not going to. And my wife, who runs marathons, looked at our results, laughed and said, ‘That’s very nice, Mike, but I’m getting a massage anyway.’ ”
No comments:
Post a Comment