It's time to lay these myths to rest, once and for all. So let's count down to the number one myth of sports science, one that began as a conclusion based on a flawed experiment on frog legs in 1920.
Myth #4: Runners don't need to strength train. To get better at running, one must run more.
It is true that runners looking to improve their performance need to run, there is no getting around that. But we often overlook the importance of strength training in our regimens, whether it be for lack of time, because we don't see it as important, because we're afraid extra muscle weight will decrease running performance, or because we'd rather run than strength train with extra time. But strength is a very important component of running that should not be ignored, for the following reasons:
- Gains made through increased strength and power output far outweigh the stress of carrying what few additional pounds of muscle mass can possibly be added on top of a high-volume, endurance-based running program.
- Increased strength can increase running efficiency, and with improved efficiency can come a decrease in running volume. Essentially, you get "more bang for your buck."
- Issac Newton's Third Law of Motion: For every action there is an equal and opposite reaction. Therefore, the ground will only return what you provide it, and strength is what's going to allow you to exert more force on the ground.
Early studies used markers on the outside of shoes to attempt to gauge the movement of the ankle. A number of more recent studies, whose findings have excited the claims of many shoe companies by suggesting anti-pronation running shoes alter the extent of pronation, used markers embedded into the shoe in a similar external attempt to monitor ankle pronation.
However, both these earlier and more recent studies were flawed in that they monitored the movement of the shoe rather than the actual ankle bones. The firmer heel-counters of anti-pronation shoes did not distort as much and therefore led to the illusion of corrected ankle pronation (Noakes 765). A notable study in 1998 concluded otherwise that, "Thus, when bone pins are used to measure the real ankle movements during running, neither running barefoot, running with shoes, nor running with shoes and orthotics altered the degree of ankle pronation" (Stacoff and others 1998). Such studies have led to the modern theory that, while shoes do not change ankle pronation, they do help one optimize their innate biomechanical form (Noakes 766).
Myth #2: A stress fractured bone heals stronger than it was before the fracture.
In the sport of running, the stress placed on the skeleton, although it can stimulate and fortify bones, can also overwhelm them and result in a stress fracture. The injury is unfortunately all too common in runners; in fact, I've experienced one myself. I remember having heard this myth and feeling a sense of elation that the chances of a reinjury were much smaller. However, my bubble was later - and rather rudely - popped when I learned that this was not true.
In fact, after bone cells called osteoblasts heal the fractured bone with new bone tissue at the fracture site, other bone cells called osteoclasts remodel the bone to resemble the old bone before injury. It is therefore no more or less susceptible to a second fracture. However, individuals with stress fracture are often recommended to take calcium and vitamin D supplements, which can strengthen the bone and stave off fractures in the future.
Myth #1: Lactic acid is the bane of a runner's existence - the source of muscle fatigue and soreness.
It's unfortunate that Otto Fritz Meyerhof's experiment, which mistakenly used frog legs that lacked circulation and therefore energy and oxygen, led to the formation of a theory that was long accepted by scientists and running coaches alike. As more recent studies have shown, lactic acid is actually an energy source. Muscles convert glycogen or glucose to lactic acid, which is then used for fuel. Lactic acid is absent from your muscles within an hour of exercise, so that soreness one may feel 24-48 hours after an intense workout is merely a case of DOMS (delayed onset muscle soreness).
If you listen closely, you may be able to hear the great sighs of relief from exercise physiologists everywhere. Lactic acid's mistaken role in energy pathways has long been seen in a negative light, and to reinform nearly a century's worth of people is certainly no simple task.
Although it is difficult to change beliefs long held by the running community, or even society as a whole, it is certainly not impossible. It serves as a good lesson in maintaining some amount of healthy skepticism when presented with any idea - to "take everything with a grain of salt." Science seemingly contradicts itself on a daily basis, so it is small wonder people have difficulty deciphering its findings. The best one can do is take an educated stance on any given idea, whether highly-contested or accepted as common belief, and roll with it. Perhaps you don't agree with the aforementioned ideas I have deemed "myths" and/or "truths," and that's absolutely okay. Healthy debate is always welcome. But the moral of the story is to be careful when taking any statement at face value; even Runner's World magazine contradicts itself rather frequently from month to month.
(1) Stacoff, A., Reinschmidt, C., Nigg, B.M., van den Bogert, A.J., Lundberg, A., Denoth, J. and E. Stüssi. Effects of foot orthoses on skeletal motion during running. (2000) Clinical Biomechanics 15(1): 54-64.
(2) Tim Noakes, M.D. Lore of Running. Southern Africa: Oxford University Press, 2001. 765-772.