A brief history of how the myth about lactic acid and massage therapy started.

Should you be concerned about the effects of lactic acid build-up in your muscles? If lactic acid really does what some people says it does, then you probably don’t want that substance anywhere near your muscular system. It is an acid. It burns, which you can feel directly, and it causes damage, which you experience as muscle fatigue or soreness. If you keep going long enough and produce enough lactic acid, then you “hit the wall.” Your body runs out of steam, and you can’t go any further.

If lactic acid does that, then it is a bad thing, even if the effects are only temporary. But that is a really big if—is it true what they say about lactic acid?

It turns out that reports of lactic acid’s effects are like a game of Telephone. It has been repeated from person to person, often getting tweaked in the telling. But the original message came from an experiment where the scientist was wrong about what he actually saw.

When the evidence shows that scientists were wrong, they adapt by changing their minds to be more right. If massage therapists change and adapt to what new evidence shows, then not only are they performing as science-based professionals and role models, but they are also delivering a powerful message to clients and professional colleagues about their readiness to become members of healthcare team members. The lactic acid massage myth is a good start.

What is lactic acid, and what does it do?

Lactic acid is an organic (carbon-based) acid found in many different natural processes. Like the words galaxies, the lactate ion, and lactation, its name shows its close connection to milk. Sour milk is where the Swedish chemist Carl Wilhelm Scheele identified it as a specific chemical compound in 1780. Its association with food continues to this day, where that sour taste is valued in foods ranging from yogurt to sourdough bread.

The closely-related chemical lactate is in the fluids given to trauma patients being treated for blood loss until they can rebuild that capacity on their own. It also appears to be a critical component in brain development and metabolism in multiple species, including humans.

Lactate is very important in muscle physiology because exercise causes your muscles to produce it from glucose and to use it for energy. But it is lactate, not lactic acid as many people still believe, it carries out that metabolic function.

Does massage really release toxins?

Not only is there no evidence that massage can release toxins—often attributed to lactic acid—from muscles, which would leave that possibility open to be shown in the future, but that idea contradicts what we know about muscle physiology and metabolism. If it were true, then what many scientists across time and cultures had demonstrated repeatedly about how our body works would be wrong.

To demonstrate the validity of the lactic acid and massage claim would take a lot of work, which is very likely to be impossible. The choice of what message that we want to send to the public is up to therapists.

Where did the myth that massage can remove lactic acid from muscles start?

The German biochemist Otto Meyerhof was awarded the Nobel Prize in Physiology and Medicine in 1922 for his work on cell physiology. He examined what was going on at a deeper level in cells and their use of energy. Although he pushed the boundaries in what had been impossible up until then and pioneered new and complex techniques to observe their actions, he got several things wrong about what those observations mean.

He published the idea that fatigue in muscles was caused by lactic acid, which in turn was caused by a lack of oxygen. People took that message and shared it with each other, changing and subtracting pieces of information and combining it with old ideas about toxic substances in the body. Thus, an industry was born.

Many people have invested in the myth that massage can squeeze lactic acid out of muscles that they are reluctant to take on the job of aligning the narrative with current scientific evidence. If massage therapy is to remain relevant in the post-Covid-19 era, practitioners must realize its potential as an actual healthcare profession.

As to what the evidence shows, Meyerhof’s idea about lactic acid began to fail very soon in scientific time—about seven years after winning the Nobel Prize. Starting with Einar Lundsgaard’s work in 1929, and continuing through many others’ research right up into the present, the evidence does not match the predictions that the lactic acid hypothesis would imply. It turned out to be lactate instead of lactic acid, and the old ideas about massage squeezing lactic acid out of muscles as a toxin was just a story, not the reality.

As for Meyerhof, even though he was wrong about the role of lactic acid in muscle fatigue, his other work has been borne out. It laid the groundwork for needed quantitative observations and theory in cell physiology and led to understanding the roles of how cells produce energy. It united chemistry, physics, and biology to show the integrated nature of physiology across scientific disciplines. By showing that these chemical processes work the same way in many different species, including humans, it highlights the unity and diversity of how life works.

Getting the role of lactic acid wrong was a mistake that needed correction, but it was not a fatal blow to Meyerhof’s body of scientific work. History is—and will continue to be—kind to him.