The idea that lactic acid builds up to a torrent in our muscles, gradually bringing exercise to a halt is a process that many athletes and gymgoers consider whenever they are attempting to push past their limits, but recent commentary from Dr Mark Burnley, who is an expert in endurance physiology, asserts that lactic acid is not responsible for muscle exhaustion. So, what is? And how can we get more from our muscles? M&F takes a look.
“There are probably three reasons for the misconception that lactate or lactic acid causes fatigue,” Burnley said in a recent interview with the UK’s top sporting University: Loughborough.“The first is an historical reason. Lactate was discovered in the late 1800s in the muscles of stags that had been hunted to exhaustion. They were found to have very high concentrations of lactate in the muscle.
So that was the immediate link: lactate causes fatigue. The second reason is that other molecules, including inorganic phosphate, and the way they work in muscles weren’t studied for another 120 years. So, humans had a very long time to be talking about lactate before anything else came along that was more accurate in terms of what was happening in the muscle.
The third reason is because there is a correlation between high intensity exercise and the accumulation of lactate because when you do high intensity exercise, you break down carbohydrates through a process called glycolysis, which produces lactate.”
Lactic Acid Does Not Cause Muscle Exhaustion
The idea that lactic acid builds up and derails our performance is part of the common lexicon. It’s repeated by sports commentators and is on many people’s minds when they are reaching failure, but the burn that you are feeling is not coming from lactic acid. While Dr Burnley says that it’s true to say that lactic acid can be found in exhausted muscles, it is not the gamechanger that many people think. “Experiments have been done both in humans and in animals and they have shown pretty convincingly that fatigue is not caused by lactate or lactic acid,” explained the expert. “What fatigue is, is a reduction in muscle force generating capacity.”
What Causes Muscle Exhaustion?
“When you’re trying to produce energy in the muscle, you break down a thing called ATP and you need to make that ATP up again because there’s not a lot of it in the muscle,” said Dr Burnley. ATP is an energy rich compound that helps us to expend force or carry load for example. The endurance expert says that when ATP is not abundant in the muscle, it must be rebuilt by breaking down phosphocreatine into creatine, and inorganic phosphate. “We know that high concentrations of inorganic phosphate can result in a loss of muscle force. And that is the dictionary definition of fatigue,” said Dr Burnley
How Can We Increase Endurance?
ATP (adenosine triphosphate) is present in meats such as chicken, steak, and fish. Some people also supplement with D-Ribose, because it speeds up ATP creation. It may also help with faster muscle recovery after intense exercise. Creatine is another supplement that helps to produce ATP, along with other ATP precursors such as CoQ10, L-Carnitine, B-Vitamins, and Beta-Alanine And, of course, to keep your body running at an optimum levels, be sure to stay hydrated and get enough sleep for best performance. With experts now believing that lactic acid has a protective rather than lethargic effect on muscles, you may be able to push past your limits with this different take on how to prolong your own endurance levels.