#12. Stretching: bad advice, good advice, and reasonable tips Monday, September 14, 2020 In 1895, Oscar Wilde wrote, "I always pass on good advice. It is the only thing to do with it. It is never of any use to oneself." 125 years later, our daily experience has changed enormously. Yet we remain inundated with advice. More than ever before. Unfortunately, the version being passed on today isn't always good. Much of it is bad. And the worst of it seems to spread through populations like a virus. And I have found the most infectious variety to be about "health" (e.g., dangerous exercise advice, ludicrous diet suggestions, and that secret cure for disease that your doctor doesn't want you to know about). A single blog entry (this one) doesn't allow us to confront the thousand tidal waves of misinformation headed our way. We only have time to wade into the shallow end for a minute. While there, we'll address a single, ankle-deep topic: stretching. Pay attention to the "wisdom" being passed on by P.E. teachers, coaches, personal trainers, running partners, and, often, strangers. It usually goes something like this: "Make sure you stretch your legs out before we get started; last thing we want here is a pulled hammie." Or sometimes, instead of injury avoidance, stretching is advised to elicit improvements in subsequent performance. After stretching, you'll run better or throw farther or something. Other times, stretching reduces post-exercise soreness. And still other times, it is meant to "warm up" the muscles you're about to use. Stretching is wonderful, but not for any of the reasons above. Those are all a little bit foolish. I'll explain their foolishness in the reverse order, beginning with the "warm up": intramuscular temperature is affected by lots of factors, the primary factor being metabolism. Active use of muscles (i.e., exercise) is metabolically expensive, and that produces heat. Passive elongation of muscles (i.e., stretching) is not. So stretching doesn't generate much warmth. Nor does it reduce soreness associated with exercise (Herbert et al., 2011). It can exacerbate soreness if it's additive, but most people subtract exercise to make room for it, which is why they get less sore the next day. Next up: injury avoidance. We don't injure our tissues during gentle, controlled motions. It happens during explosive, out-of-control motions, such as sprints and direction changes. Gentle stretches immediately beforehand do not prepare a tissue to withstand explosive motions immediately afterhand (Small et al., 2008). Long-term flexibility routines can reduce the risk of several types of injuries, but when it comes to the acute, sport-related variety people warm up to avoid, weight lifting is a much more effective preventive strategy (Lauersen et al., 2014). Lastly, stretching does not enhance subsequent performance. It is much more likely to compromise it. Immediately after a bout of static stretching (those gentle stretch-and-hold postures), muscle strength and power are weakened. Jumping, sprinting, throwing, any sort of heavy heaving: ruined. Men and women, old and young: all susceptible. The longer the stretch is held, the more the subsequent performance suffers. If you stretch for half a minute as part of a comprehensive warm up, it's no biggie. But if you hold it for two minutes, you'll be a terrible athlete for many more minutes to come. You'll experience poor neural activation of your tissues, and you'll stretch out the "viscoelastic" properties of your muscle-tendon unit (called the "series elastic component" and the "parallel elastic component"). In other words, you stretch out the waistbands of your muscles and, for a time, they won't snap back into place as hard. So you don't run as fast, jump as high, or throw as hard. Shorter static stretches (under 60 seconds) have a marginally-compromising effect; longer static stretches (over 60 seconds) have a majorly-compromising effect (Chaabene et al., 2019). "It sounds like stretching is pointless where it isn't bad. Should I skip stretching altogether?" No, definitely include it. I wasn't lying when I said it was wonderful. It's just prized for the wrong reasons. What are the right reasons, you ask? The rightest of them all is posture, I answer. What keeps you upright is the opposition of forces (opposite muscles tugging against each other). For every bicep, there's a tricep. Every hamstring has a quad. Every abdominal has a bunch of overworked spinal erectors. In other words, if you're currently standing, you have plenty of postural muscles contracting, pulling on your skeleton in directions that oppose each other. While upright, if you stop recruiting those muscles, you'll become downright. You'll collapse in a hurry. But falling in this way isn't the problem. The problem lies in the balance of forces. When yin grows tighter than yang (e.g., your chest grows tighter than your upper back), your posture changes. In this particular case, your shoulders roll forward. Yin and yang disputes can manifest at numerous sights in the body. And these are the problems stretching is best at correcting. That's enough background. Let's have us some tips: Tip 1) Skip the static stretching prior to performance. The reach-and-hold-forever variety. Not unless the performance you're preparing for involves long, static stretches. Like it's a stretching exhibition or something. For all other exhibitions, just warm up. Performing light exercise, ideally mimicking the motions that will follow, will work best. Tip 2) After exercise, when you're all warm, relaxed, and limber, wrap up your session with some static stretches. Pick three or four that will be best for your frame. To do this, think about your routine postures. Knees bent, hamstrings shortened, as you sit for long hours? Perhaps with your shoulders rounded forward? That kind of slouching and hunching can be corrected by stretching in the opposite direction. Tip 3) If your daily routine (a sport, a job, a hobby) involves ranges of motion that strain your tissues more than you'd like, invent some stretches to remedy that problem. Likewise, if increasing that range would enhance your performance, invent some more and really stick with them.