Which Comes First, Cardio or Weights_ - Alex Hutchinson [62]
The next month, a different Dutch team published another clinical trial, this time with positive results. In a group of 100 patients with tennis elbow, 73 percent of those given PRP reduced their pain by at least 25 percent after a year, whereas only 49 percent of those who received a corticosteroid injection achieved similar results. Again, the study was blinded so that the patients didn’t know which procedure they were receiving.
The shots typically cost about $500 each, and a full course of treatment including imaging can exceed $2,000. With that in mind, you can balance the benefits of a promising but unproven treatment against the cost—and how long you’ve been struggling with the injury. It’s worth noting that, even in the unsuccessful trial, both the PRP and placebo groups did improve significantly during the study (by about 20 points on a 100-point pain scale). The authors note that “placebo response is amplified when a treatment is invasive and raises high expectation.” In other words, the shots could work if you believe in them.
How can I reduce my risk of stress fractures?
Evan Lysacek had one in his left foot the year before winning the 2010 Olympic gold in men’s figure skating. Tiger Woods had two in his left leg. A Globe and Mail reporter even got one from dashing between parties at the Toronto International Film Festival in high heels. Stress fractures are among the most common—and dreaded—diagnoses in athletes. Striking most often in sports that involve running and jumping, they usually signal the end of an athlete’s season, since the only treatment is rest for 8 to 10 weeks or more.
Bone is a living tissue, in a constant balance between breakdown and repair. When the damage from repeated impacts builds up more quickly than it can be repaired, microscopic cracks begin to form. Eventually, these cracks join together to form a stress fracture—a hairline crack in the bone that results from weeks or months of accumulated pounding rather than from a single traumatic blow. The single most important factor in preventing stress fractures is having strong, healthy bones. But new research suggests a couple of other factors that might reduce your risk.
The first comes from researchers at Iowa State University, who used a computer model of bone damage and repair to estimate the effects of changing your stride length. Basically, if you shorten your stride, you’ll have more foot-strikes per mile (and thus more impacts jarring your bones), but each foot-strike will be a little gentler. So which effect predominates? The researchers had 10 runners run on a treadmill with different stride lengths, measuring the relevant forces with motion-capture cameras and force plates, then plugged the data into their computer model. The conclusion: shortening your stride length by 10 percent reduces stress fracture risk by 3 to 6 percent.
Changing your running stride definitely isn’t easy (see Chapter 4). But other studies have found that one of the chief sins of inexperienced runners is overstriding: elite runners tend to take about 180 steps a minute regardless of how fast they’re running, while less experienced runners take fewer steps. So focusing on taking short, quick steps could have multiple benefits—including lowering your stress fracture risk.
The second factor comes from a study of 39 female runners, half of whom had a history of stress fractures. Researchers at the University of Minnesota took a series of measurements to determine the size, structure, and density of the subjects’ bones and muscles. Not surprisingly, the shin bones in the stress