The Lactic Acid Debate

By Diana L. Thompson
[Somatic Research]

True or false: massage after exercise assists in the removal of lactic acid. Answer: false.

The research overwhelming refutes this commonly held and frequently exclaimed belief. The lactic acid debate has raged for a century, and for the past two decades the research consistently demonstrates that blood lactate will return to normal within 20–60 minutes post-exercise, regardless of intervention. Yet, massage schools continue to teach this flawed lactic acid theory and massage therapists still declare it as truth to clients and the media.

It is time to reform our declaration on the benefits of massage for clients. It is essential to stop perpetuating a false theory. As a result of this pervasive myth, articles are published making damaging claims about massage, such as, “Research questions efficacy of massage as an aid to recovery in post-exercise settings” and “Massage not an effective treatment for enhancing long-term restoration of post-exercise muscle strength and its use in athletic settings should be questioned.” Undocumented claims, such as “massage assists in the removal of lactic acid,” draw attention and will be tested. The negative results become fodder for those looking for a shocking headline.

Even if massage does not help move lactic acid, thousands of elite athletes and trainers can’t be wrong when they commit valuable resources to pack up massage therapists and take them across the country on bike races, or provide precious space in the medical tents at the Olympics, or allow the female massage therapist an unprecedented seat on the bench in the San Diego Padre’s dugout. Massage does work. But, in an era of open access to research and the push for evidence-informed practices, we must heed the available data and speak accurately about what we do and why it works. When we fail to do so, it comes back and bites us where it hurts. We must better understand the known physiological effects of massage and how massage benefits our clients to be able to refute gross conclusions that don’t accurately reflect our role in helping athletes recover from post-exercise symptoms.

In order to better understand why the belief that massage removes lactic acid is false, we need to better understand blood lactate and the causes of post-exercise symptoms. The first questions to explore are: what is lactic acid or blood lactate and what does it do? If lactic acid buildup doesn’t cause muscle soreness and fatigue, then what does? Does massage enhance performance, relieve muscle fatigue, and reduce muscle soreness? If so, how? What do we know about the physiological effects of massage and what has yet to be demonstrated through research?

Once we have appraised the best available information, we can reform our statements about how massage benefits clients. Then we need to encourage all massage therapists to promote the best available data on the benefits of massage to clients. Finally, it is important to inform the next generation of research to encourage questions meaningful to practitioners. We can submit questions that we confront regularly in practice, identify the theories we dispute, and hopefully provoke someone to explore potential answers.

The Article Prompting this Conversation

In 2009, at the American College of Sports Medicine (ACSM) conference in Seattle, hundreds of research presentations were given from podiums and thousands of posters were shown. Typically, oral presentations are awarded to the more rigorous studies, or studies of greater significance, and posters are awarded to those that show merit but do not meet the more rigorous standards of a speaker’s slot. Yet, the research summary on massage therapy that was picked up by that week was titled, “Massage After Exercise Myth Busted.”1 The opening line read, “A Queen’s University research team has blown open the myth that massage after exercise improves circulation to the muscle and assists in the removal of lactic acid and other waste.” Recently, the article was published in Medicine and Science in Sports and Exercise (many conference research presentations and posters present data that may take months, or even years, before it is published).2

Last year, prompted by the article, several massage therapists and scientists were engaged in a flurry of emails critiquing the study.3 Several problems with the study were identified. The most obvious flaw is the sample size. There were only 12 subjects and three arms of the study. It is unclear if all 12 received all three protocols or if the 12 were divided up, placing four subjects into each arm of the study. Both scenarios present weak numbers, reflecting a low level of evidence.

The next discernable error was in the protocol. It is not practical to make massage therapy available to athletes immediately following the completion of strenuous exercise; massage within 10 seconds of exertion is not consistent with massage as it is practiced in the field. Most athletes will do a cooldown of sorts, rehydrate, and in the case of long-distance races, refuel before trotting into a medical tent to receive massage. The science states that blood lactate returns to normal within 20–60 minutes, depending on the fitness of the athlete. If massage were applied as practiced, the lactic acid would have been eliminated by normal means regardless.

In addition, for this article to claim that, “Ours is the first study to challenge this and rigorously test its validity” is not exactly accurate. There is a decent body of evidence that already suggests that massage has little effect on the removal of lactic acid after exercise. While this study may be the first to look at the rate at which the lactic acid is removed, a serious literature search would have produced enough evidence that the effects of massage on blood lactate is of little importance.

The study has flaws, but the real issue is that we, as a profession, continue to inaccurately promote massage as an effective tool to remove lactic acid from muscles. The researchers were prompted to study the effects of massage on lactic acid because the Canadian Sports Massage Therapists website ( lists the removal of lactic acid from muscles as a benefit of massage. Therein lies the problem. Unless we discontinue promoting false claims about massage, researchers will continue to find fault with our theories, and the media will inflame the results, concluding that massage is bad for athletes. In this case, the story was perpetrated twice—once when presented as a poster at a conference, and secondly after publication in a journal. Ouch.

What is Lactic Acid?

The search for the cause of muscle soreness and fatigue began more than a century ago. In the late 19th century, fermentation chemists realized that juice left to ferment without adequate oxygen resulted in acid products. In the early 20th century, when physiologists stimulated isolated frog muscles to contract until exhaustion, they found that the tissues had accumulated high amounts of lactic acid. Since then, the idea that lactic acid accumulation causes muscle fatigue has persisted.4

More recently, the lactic acid paradigm has shifted. Lactic acid is understood to be more than just a waste product of exercise. Lactic acid is the result of the glycolytic energy production system. In other words, muscles make lactic acid to fuel cells not only in the muscle that produced the lactate, but also as an energy source that can be shuttled off to adjacent muscle cells for fuel. Lactic acid has also been found to fuel fibers in the heart and cells in the brain. The liver prefers to use lactic acid to make glucose for the blood when exercise is prolonged. The production of lactic acid is stimulated, in part, by circulating adrenalin; the combination of adrenalin and lactic acid helps protect against the electrolyte imbalance across muscle membranes brought on by the loss of potassium.5

Lactic acid is not simply the end result of an oxygen-deprived muscle, accumulating and resulting in muscle fatigue and soreness. Rather, it is an important intermediary in numerous metabolic processes and pathways within and between cells. It is a central player in cellular, regional, and whole body metabolism. The original cell-to-cell lactate shuttle explaining muscle and exercise metabolism has escalated to include lactic acid as a key contributor of energy supporting nearly every metabolic function in the body.6

Another group of scientists explain the link between oxygen-based aerobic metabolism and oxygen-free anaerobic metabolism. Muscle cells use carbohydrates anaerobically for energy, producing lactate as a byproduct, but then burn the lactate with oxygen to create far more energy. During normal exertion, the lactate seeps out of the muscle cells into the blood to be used elsewhere. During intense exercise, the rapidly accumulating lactate is burned more rapidly to create more energy. Endurance training teaches the body to efficiently use lactic acid as a source of fuel on par with carbohydrates stored in muscle tissue and sugar in blood. Efficient use of lactic acid not only prevents lactate buildup, but ekes out more energy from the body’s fuel.7

Physicist and massage therapist Keith Eric Grant, PhD, offered an interesting analogy for lactic acid in the email exchange mentioned earlier: “The picture of lactate that emerges is much like that of charcoal to wood. Lactate is not a waste product but a further metabolic participant and source of fuel to muscles. As charcoal is partially oxidized wood, lactate is partially burnt fuel.”

The Role of Massage in Muscle Recovery

Now that we understand that lactic acid is not waste to be flushed out of the muscles, what is the cause of muscle soreness and fatigue and what role do we have in relieving those post-exercise symptoms?

We know that training helps people burn lactic acid more efficiently by growing the mitochondria in muscle cells. The mitochondria are where the lactate is burned for energy. Intense exercise, particularly interval training, generates big lactate loads, and the body adapts by building up mitochondria to clear lactic acid quickly. Overtraining, on the other hand, can kill muscle cells.8

We know that delayed onset muscle soreness (DOMS) is the pain or discomfort often felt 24–72 hours after eccentric contraction exercise or exertion accompanied by unaccustomed training levels—once thought to be caused by lactic acid buildup but now attributed to inflammation and micro-tears in the muscle fibers, fascia, and nociceptors.9

The research says massage reduces soreness and swelling in athletes post-exercise, and significantly reduces pain in people experiencing DOMS by as much as 25–50 percent.10 The research literature to date is insufficient to conclude whether massage facilitates recovery from a fatiguing effort. Both tissue healing and a psychological effect of massage are areas that may prove promising with further research. Results from published literature support a positive trend for massage to benefit athletic recovery and performance, and a need for further study is warranted.11

Reform Our Claim

While we do not yet understand the mechanisms involved in the reduction of soreness and decreased swelling through the application of massage therapy, we can confidently say those are benefits of massage, not just for athletes but for anyone suffering from pain or inflammatory conditions.

Resist the urge to explain the statement “massage can significantly reduce pain and swelling” and simply and confidently assert the truth. In the meantime, encourage researchers to continue to explore how massage works, and what effects massage might have on fatigue and tissue healing.

 A licensed massage practitioner since 1984, Diana Thompson has created a varied and interesting career out of massage: from specializing in pre- and postsurgical lymph drainage to teaching, writing, consulting, and volunteering. Her consulting includes assisting insurance carriers on integrating massage into insurance plans and educating researchers on massage therapy theory and practice to ensure research projects and protocols are designed to match how we practice. Contact her at


1. “Massage After Exercise Myth Busted,” accessed January 2011,

2. E. Victoria Wiltshire et al., “Massage Impairs Postexercise Muscle Blood Flow and ‘Lactic Acid’ Removal,” Medicine and Science in Sports and Exercise 42, no. 6 (June 2010): 1062–71.

3. Respondents included John Balletto, Bruce Gladden, Keith Eric Grant, and Albert Moraska.

4. “The Strange Tale of Muscle Lactate: When the Villain Becomes Your Friend,” accessed January 2011,

5. Ibid.

6. L.B. Gladden, “Lactate Metabolism: A New Paradigm for the Third Millennium,” Journal of Physiology 558 (July 1, 2004): 5–30.

7. “Lactic Acid Not Athlete’s Poison, But An Energy Source—If You Know How to Use It,” accessed January 2011,

8. Ibid.

9. P. Bakowski et al., “Effects of Massage on Delayed-Onset Muscle Soreness,” Ortop Pol 73, no. 4 (July–August): 261–5.

10. Ibid.; Z. Zainuddin et al., “Effects of Massage on Delayed-Onset Muscle Soreness, Swelling, and Recovery of Muscle Function,” Journal of Athletic Training 40, no. 3 (July–September 2005): 174–80; L.A. Frey et al., “Massage Reduces Pain Perception and Hyperalgesia in Experimental Muscle Pain: A Randomized, Controlled Trial,” Journal of Pain 9, no. 8 (August 2008): 714–21; P. Weerapong, P.A. Hume, and G.S. Kolt, “The Mechanisms of Massage and Effects on Performance, Muscle Recovery, and Injury Prevention,” Sports Medicine 35, no. 3: 235–56.

11. A. Moraska, “Sports Massage. A Comprehensive Review,” Journal of Sports Medicine and Physical Fitness 45, no. 3 (September 2005): 370–80.