Just the term “lactic acid” resonates with evil, conjuring up the image of acid pouring into working muscles and eventually burning them into submission. Lactic acid seems like such a perfect culprit to blame for pumped forearms or even for delayed onset muscles soreness (DOMS – the topic for the second set of entries in this series, coming up a few weeks down the road). This supposedly villainous substance can rise to such concentrated levels when we exercise that we can no longer use our hands and arms properly.
If you listen to plenty of climbers, announcers for other sports, athletes and coaches, and even (most surprisingly to me) to a college-level course that I recently took, this is dead-on. According to these sources, when we work out at a high level, after a certain period of time, lactic acid eventually just saturates our muscles, and then we’re done.
Only, this isn’t really the case.
“Lactic acid [actually, lactate] is in fact a crucial fuel for your muscles, not a painful waste product,” explains Alex Hutchinson in his excellent book, “Which Comes First, Cardio or Weights?: Fitness Myths, Training Truths, and Other Surprising Discoveries from the Science of Exercise.” This book compiles numerous interesting discoveries and clarifications emerging from recent exercise science research. Grab a copy and read the third chapter for more details about how the lactic acid myth came into being (in 1907), and how long it has taken to get it out of currency (well, it’s still out there, providing a perfect example of how common knowledge doesn’t necessarily mean correct knowledge – something that is very important to keep in mind when evaluating all things related to training, exercise and trying to improve your climbing!).
“In fact,” Hutchinson clarifies, “you’re constantly converting your carbohydrate stores into lactate, even when you’re at rest.” And right away, your body converts roughly half of this lactate into ATP. This conversion doesn’t require oxygen (it’s anaerobic). When you exercise, that number can rise to 80 percent of lactate generated being used to power working muscles. Fit athletes, while churning out about the same amount of lactate as unfit folks, can use that lactate more effectively for fuel.
High levels of blood lactate during intense exercise signify a body that’s not as efficient at using lactate for fuel – not muscles drowning in copious amounts of lactic acid that’s eating away at their ability to function.
So what does account for that burning pump that makes it so hard to hang on for one more move for so many climbers?
Until recently, scientists had yet to come up with solid evidence for the causes of this – but (very!) recent research has shed new light on some of the possible physiological mechanisms responsible the fatigue and pain that can force us to call it quits, whether we want to or not. Check out “What Causes Muscle Pain During Hard Exercise?,” a June 2014 article by Hutchinson published in “Runner’s World,” for details on one possible explanation – that it’s a specific mix of metabolites (products of metabolism) that, when they build up together, prompt this type of muscle fatigue and pain, as evidenced by a study published in the April 2014 issue of “Experimental Physiology.”
Perhaps the most fascinating aspect of this study is the fact that none of the metabolites on their own led to feelings of fatigue or pain; it was only the combination of metabolites together that did this. As the authors of the study concluded, “This is the first demonstration in humans that metabolites normally produced by exercise act in combination to activate sensory neurons that signal sensations of fatigue and muscle pain.”
The jury is still out, though, on whether it’s these feelings of pain and fatigue that cause you to stop being able to function continuously at the same level, or if there’s another (or several other!) mechanism(s) involved that actually slow down the muscles and makes them less responsive that’s independent of the pain and fatigue messages being sent to your brain via your metabolite-sensitive nerves.
Want to read more? Check out “Lactic acid restores skeletal muscle force in an in vitro fatigue model: are voltage-gated chloride channels involved?” and “The Myth of Lactic Acid Refuses to Go Away!” (the latter has numerous links to more articles about this sports myth as well).
Up Next Week: Climbing & Training Helpful Hints & Suggestions 1: Lactate Threshold Training, Part 1
This multipart series of articles starts here, in case you have to catch up – you’ll also find a full table of contents, complete with links, in that entry. This information and advice is based on my 20+ years of climbing along with observations I’ve made as a climbing coach/certified personal trainer. You might not agree with me or my take on things. That’s fine – feel free to take it or leave it as you wish! Also, remember that the information I provide here is purely offered as advice and that no exercises or training program should be undertaken without receiving medical clearance from a healthcare professional.
One other caveat: As will be true for all of the entries and articles in this series, if you’ve already mastered or maxed out the topic at hand to the best of your ability level, you’ll reap far fewer benefits or none at all from my suggestions – good for you that you figured it out, but sorry I couldn’t help you out more. Happy climbing and training!