Which Comes First, Cardio or Weights_ - Alex Hutchinson [51]
This effect likely stems from the remarkable ability of your muscles and tendons to store energy like coiled springs, providing an estimated 40 to 50 percent of the energy you use for each step. “If you decrease the stiffness of the muscles and tendons, then you can’t store and reutilize energy as well,” explains Jacob Wilson, an exercise physiologist at Florida State University. The connection is less pronounced in women, who are generally more flexible to start with. And the initial studies only measured correlations, rather than showing that increasing your flexibility actually causes lower running economy.
To address this gap, Wilson and his colleagues asked 10 male runners to complete a pair of one-hour tests consisting of 30 minutes running at a predetermined pace to measure running economy, followed by 30 minutes as fast as possible. Before one of the tests, the subjects did 16 minutes of “static” stretching—the most common technique, which involves stretching a muscle to the edge of its range of motion, then holding for 30 seconds. Sure enough, the non-stretchers burned about 5 percent fewer calories in the first part of the run and ran 3.4 percent farther in the second part. Though it was already well established that static stretching causes a temporary decrease in strength and power, the 2010 study marked the first time the effect had been observed in an endurance activity.
That doesn’t mean you should leap into exercising with no warm-up—it just means you should rethink how you warm up. New results from a follow-up study by Wilson and his colleagues suggest that, unlike traditional static stretching, an alternative approach called “dynamic” stretching doesn’t hurt running performance.
How should I warm up before exercise?
After reading the last few pages about the negative effects of static stretching before your workout, you might be thinking, “Great! Now, instead of wasting my time warming up, I can get down to business right away.” Nothing could be further from the truth. In fact, the stretching studies reinforce the point that subtle differences in how you prepare your body can make a big difference in your performance during a workout or competition.
The general goals of a warm-up are “to increase muscle and tendon suppleness, to stimulate blood flow to the periphery, to increase body temperature, and to enhance free, coordinated movement,” according to a group of U.S. Army researchers who studied the problem in 2006. A gentle jog accomplishes some of these goals—raising body temperature, for instance—but it doesn’t do much to prepare the specific muscles that will help you lift a weight, throw a ball, or cut sideways across the court. Instead, you need to perform a series of exercises that move your muscles through the full range of motion that you plan to use, at first gently and then with increasing vigor. This is a dynamic warm-up, focused on movement rather than the static poses of a traditional stretching routine.
Over the past decade, a series of studies has tested the principles of dynamic warm-up. The U.S. Army study had recruits perform one of two 10-minute warm-up routines, one dynamic and one static. Those who performed the dynamic warm-up produced significantly better performances in three tests of agility and power (a shuttle run, an underhand medicine-ball throw, and a five-step jump), compared with static stretchers and those who did no warm-up at all. Other dynamic warm-up studies have found improvements in vertical jump, bicycle sprint, oxygen uptake, and even coordination.
Most of these studies focus on the acute effects of warming up—after all, we’re most interested in how our warm-up affects the workout that follows. But University of Wyoming researchers posed an interesting question in a 2008 study: What are the long-term benefits of repeated dynamic warm-ups? Using the same warm-up routine as the Army study, the researchers monitored a group of collegiate wrestlers for four weeks. At the end of the trial, the dynamic warm-up group had improved on a whole