I found the title of The Skeptic’s Guide to Sports Science: Confronting Myths of the Health and Fitness Industry a bit misleading. I was expecting to find a list of sports myths debunked by scientific evidence, but what I found was much better. It does debunk several sports-related myths, but the majority of the book is devoted to providing a very valuable education in critical thinking. It inspires readers to look for the evidence behind any claim they hear and develop an appreciation for “the true knowledge and wonder that science can afford.”

Nicholas Tiller starts by explaining that evolution hardwired us for heuristic thinking because of the survival advantage. Heuristic thinking uses mental shortcuts and allows us to ignore certain bits of information. It is practical for making quick decisions but does not guarantee that our decisions are optimal—or even correct. He quotes Bertrand Russell on the times when instinct and reason conflict: “Instinct … is liable to error. Those in whom reason is weak are often unwilling to admit this as regards to themselves, though all admit it in regard to others.”

We seek “one quick fix,” quick rewards, and instant gratifications; we enthusiastically buy into any ergonomic aid that promises to enhance performance by mechanical, psychological, physiological, or nutritional means. Runners who want to shave seconds off their best times find it much easier to buy expensive new running shoes (that accomplish nothing) than to reevaluate running styles and training programs (which might really do something to improve their performance times). And then there’s tribalism, the instinctive pleasure we derive from belonging to a group, such as the group that owns the latest bike or magic bracelet.

False advertising? Tiller shows how regulatory efforts have failed, how the Dietary Supplement Health and Education Act of 1994 (DSHEA) undermined the work of the Federal Drug Administration, and how “post-truth era” thinking and social media have made it harder than ever to distinguish fact from fiction.

Failures in education? Critical thinking skills are seldom taught in our schools. The internet has given us access to a flood of data, outstripping our ability to interpret it. As Tiller says, “information is not knowledge.”

Clever marketing? He describes how supermarkets employ clever marketing techniques that use our psychology and biases to influence our buying decisions. They manipulate us into “not thinking too much.” The same techniques are used to sell sports products.

Tiller is optimistic that people can learn to collate meaningful data, filter it for validity, and reach coherent evidence-based conclusions. As a teaching exercise, he asks his students to consider how they made a decision about a significant financial investment, what research strategies they used, and how they collected as much information as possible from a variety of sources. Contrast that with how willingly they believe whatever a coach or trainer tells them, without asking questions or doing any research of their own. He gives examples of how even well-trained scientists are biased, especially about claims outside their own areas of expertise. Sometimes there is evidence to support both sides of a heated debate, but the evidence is insufficient to reach a consensus; once a scientist has chosen sides, tribal bias kicks in. As an experiment, Tiller tried to design three products that were superficially plausible but ill-conceived and unlikely to be effective. He discovered that “no matter how far-fetched the idea or how tenuous the science underpinning it, an equivalent product was already on sale.” In fabricating a bogus sales pitch, he was struck by how easy it was—and how much fun.

Tiller tries to explain valid and invalid reasons for buying a product. Among the invalid reasons: appeal to popularity, jargon that sounds like science but isn’t, appeal to antiquity, argument from authority, appeal to nature, ambiguous or vague language, celebrity endorsements, false dichotomy, confusing correlation with causation, and the appeal to anecdote (the plural of anecdote is anecdotes, not data).

The book warns about the slippery slope: pseudoscience breeds pseudoscience. He lists red flags: claims that commit logical fallacies, products sold on testimonials or anecdote, alternative medicine, emotive language, multiple claims, and lack of prior plausibility. There is a whole chapter on how to evaluate research and what to look for when reading a paper. Another chapter explains the appeal of placebo products and the power of perception.

Tiller discusses the contentious world of sports nutrition, decrying fad diets, superfoods, juicing, and detox regimens. He stresses that unhealthy foods don’t exist. The media routinely distort information about nutrition. A notorious study claiming that chocolate helps people lose weight was a real (although seriously flawed) study that was actually a sting designed to test how the media would report a study with questionable results from a fake research center by an uncredentialed researcher published in a bogus journal; the news media failed the test miserably.

For many years, we thought moderate drinkers lived longer than non-drinkers, but the research was flawed and doesn’t actually back up that claim. Evidence is lacking for claims that organic foods are more healthful. Fructose is not inherently worse than sugar, and “detox” is a myth.

Dietary supplements? Usually not helpful, and they sometimes have fatal consequences. Many are mislabeled or contaminated with prescription drugs and prohormones. Food is better.

Fat-burning supplements are deceptively marketed. Recommendations for protein intake ignore important factors. Sports drinks are long on claims but short on evidence. Novel training programs and products must be tested. He also quotes Sherlock Holmes: “It is a capital mistake to theorize before one has data: insensibly one starts to twist facts to suit theories instead of theories to suit facts.”

Barefoot running? Much of the research was done on people who habitually wear shoes; barefoot runners develop different techniques. High altitude training? The devil is in the details; there are caveats and confounders. Power bracelets are useless trinkets, and nasal strips have subjective effects only. Complementary and alternative medicine? Based on belief, not evidence. Non-evidence-based practices include cupping, Reiki, acupuncture, Traumeel, yoga, cryotherapy, and chiropractic.

This book covers a lot of territory that is covered elsewhere, but approaching critical thinking in the context of sports is new and useful. It should be particularly helpful to those who have been misled by sports myths and misinformation or who have unquestioningly accepted whatever a trainer, coach, or friend told them. One of the most telling anecdotes in the book is about a scientist friend (who should have known better) who is firmly convinced of the truth of a claim but admits she has not looked at the scientific literature.

I learned some fascinating bits of trivia. I knew Coca-Cola’s original formula contained cocaine, later replaced by caffeine. But there was more to the story. After a legal battle, the originally high caffeine content was decreased by court order. Today’s product does actually contain coca, but the psychoactive alkaloid is removed at a heavily guarded chemical processing facility in New Jersey. Who knew?

Tiller’s information is accurate and supported by references, and his treatise on critical thinking is brilliant. I had only two quibbles: he misspells James “The Amazing” Randi’s name as “James Rhandi,” and he likes to insert hyphens where they are not needed (critical-thinking, ad-campaign, far-exceeded, etc.).