Which Comes First, Cardio or Weights_ - Alex Hutchinson [27]
Of course, there are many other ways to monitor your training, starting with the humble stopwatch. But if you crave objective data, love cutting-edge technology, and have always wondered how you stack up with Lance Armstrong, the tests are easily available. “There’s a misconception that it’s only serious, elite athletes who do this,” Johnston says. “But we see a huge range of people. It’s for anyone who wants to be fit, but also has a performance goal they’re working toward.”
How can I avoid muscle cramps?
Researchers from Brigham Young University reported an odd finding in 2010: drinking a quarter-cup of pickle juice gets rid of muscle cramps within an average of about 85 seconds, 45 percent faster than they’d disappear on their own. What’s interesting about this is not the promise of a “cure”—85 seconds is still a long time to be in pain—but the question of why it works. For years, we’ve been told that muscle cramps result when you become dehydrated and lose too many electrolytes, the salts that are carried away in your sweat. But this tiny amount of pickle juice isn’t enough to restock fluid or electrolyte levels in the body, and the effect occurs long before the pickle juice could possibly be absorbed from the small intestine.
Instead, researchers are now considering the possibility that cramps are a phenomenon related to “altered neuromuscular control,” stemming from several factors, including fatigue, muscle damage, and genetics. The new theory doesn’t offer any quick fixes, but it suggests that proper training and pacing could help minimize your risk.
The first studies of muscle cramps date back over a century, to studies of miners and steamship workers laboring in hot, humid conditions. The idea that replacing the water and salt lost in sweat would prevent cramps developed from these early observations—but no controlled trial has ever managed to show that it actually works. In fact, several studies comparing cramp-prone Ironman triathletes to their non–cramp-prone peers by researchers at the University of Cape Town have found that hydration and electrolyte levels in the two groups are almost indistinguishable before and after the race. And a forthcoming study from the Brigham Young group forced volunteers to exercise until they lost 3 percent of their body mass through sweat but found no change in their susceptibility to electrically stimulated cramps.
The neuromuscular cramp theory was first proposed in 1997 by University of Cape Town sports physician and researcher Martin Schwellnus, to explain simple observations like the fact that the muscles affected are usually those that have been working hardest. “If it’s a systemic problem like dehydration, then why doesn’t the whole body cramp?” he asks. In addition, he adds, sports doctors working in the medical tent at athletic events have long known that the best way to relieve a cramp is to stretch the affected muscle—another hint that the problem is local rather than general.
Your muscles are always held in a delicate balance between two types of reflex signal carried by the nervous system: an excitatory input that encourages them to contract, and an inhibitory input that encourages them to relax. Schwellnus believes that several factors associated with exercise can upset this balance, increasing the signal from the excitatory reflex and lowering the signal from the inhibitory reflex. When this occurs, he says, “the muscle gets twitchy.” If the imbalance persists, the muscle will eventually contract in a full-blown cramp.
Factors that can affect the balance and make your muscles twitchier include fatigued or damaged muscle fibers, which would explain why cramps generally occur in the hardest-working muscles. Experiments with rats suggest the vinegar in pickle juice can alter these reflex signals, and the fact that cramping often runs in families suggests a genetic component. In contrast, stretching a muscle triggers the inhibitory reflex, which explains why it