Scientific knowledge is accessible to more people today than ever before, yet the relationship competitive sports and the fitness industry share with medical quackery, useless gimmicks, and anti-scientific concepts are as strong as ever. It may be worse than ever, thanks to social media, which now amplifies and delivers lies on an enormous scale.

Nick Tiller is pushing back against the avalanche of bad ideas that millions keep falling for. As an exercise scientist, ultramarathon runner, and former physiologist for the British Olympic program, he understands just how severe this problem is. Tiller currently works as a researcher at Harbor-UCLA Medical Center in California. His brilliant book, The Skeptic’s Guide to Sports Science, is a powerful takedown of numerous sports/fitness delusions and deceptions. His advice and warnings are invaluable to both serious athletes and all who simply want to improve their health and fitness. I had the chance to ask him some questions about his work.

Just how big of a problem is fraud and medical quackery in sports and fitness today?

Nick Tiller: The industry is one of the world’s biggest—worth over $4 trillion. This is more than the fast food, smartphone, and social media industries combined. Little to no regulation means marketing companies have no obligation to science or evidence. So, the industry has been overrun by baseless claims with most products not delivering on their promises. This harms the consumer when they fail in their wellness goals and has implications for population health and clinical practice. Many lives have been lost, and many billions of dollars in economic damages stem from homeopathy, harmful detoxes, and other pseudoscience.

Based on your experiences and observations, what are a few of the most popular pseudoscience treatments and gimmicks in sports?

NT: Dietary supplements are everywhere, but only a tiny percentage have supporting evidence. Chiropractic treatment is very popular, particularly in the NFL—most teams have chiropractors on their payrolls. Acupuncture is also very common.

Can you share any examples of smart athletes who fell for incredibly dumb things?

NT: Novak Djokovic—arguably the greatest tennis player of all time. Clearly, he is a very intelligent individual who’s regularly a victim of his superstitious beliefs. Aside from being deported from Australia in 2021 for violating their COVID-19 vaccination policy, he uses green algae smoothies to detox, infrared “energy emitting” devices to energize him during matches, and regularly visits the Pyramid of The Sun in Bosnia and Herzegovina to harness its “healing energies.” It’s difficult to argue with his results, but his accomplishments have come despite his beliefs, not because of them. Of course, we cannot ignore the powerful psychobiological effects that are the basis of placebo.

What should consumers look out for when considering workout plans, training equipment, or supplements?

NT: There are several red flags to look for. Be cautious of interventions that claim to confer numerous benefits—no product can treat everything. Note that any meaningful outcome takes time to achieve, many months or years, so be skeptical of anything that offers rapid results. And watch out for popular buzzwords: anti-inflammatory, detox, immune boosting, natural, organic, etc. These terms aren’t scientific, are usually misappropriated, and are an attempt by the vendor to blind you with science.

Many online health and fitness influencers push nonsense concepts and sell worthless supplements. How can people spot the bad ones?

NT: We live in the post-truth era, a time when emotions and personal beliefs are more influential than objective facts. Nowhere is this truer than on social media. If you intend to engage with health and wellness content online, look closely at the influencer’s qualifications. Are they qualified to give this advice? Consider the motives behind the content and disregard advice in sponsored posts. Avoid quick fixes. Judge advice on merit and check whether it conforms to scientific/expert consensus. And filter out “fitspiration” content that’s all style over substance.

What would be a better regulation system that would give people a fair chance of buying safe, useful, and reliable supplements?

NT: The health and fitness industry is the Wild West. I’d like to see mandatory FDA approval for products and services before they go on sale. Currently, this only applies to medical devices that make specific claims about disease. Manufacturers should have to provide evidence of safety and effectiveness for new products. In a rather backward system, products are only currently withdrawn if there’s evidence of active harm. In effect, we’re all guinea pigs in a vast commercial experiment. For any of this to work, federal agencies need to be expanded because they don’t have the capacity to investigate all claims for all products.

Do most people who exercise or just want to be healthy need to take supplements?

NT: No. Most supplements have little to no benefit. The exception is when a doctor diagnoses a nutrient deficiency and prescribes oral or injectable supplements. Most of the time, a balanced diet should suffice. Elite athletes push, pull, and tear at their bodies and may see more benefits, but the list of effective supplements is very small. Supplements represent the quintessential quick fix, the ultimate perceived shortcut to health and fitness, hence why they’re a reliable source of income. There are around 30,000 different supplements on sale in the U.S. alone.

What advice would you give to ambitious young athletes who say they will do anything to win?

NT: Your commitment is admirable. And, in the hyper-competitive world of performance sports, that single-minded determination is crucial if you’re to stand a chance of success. However, keep in mind that many people in the commercial world want to turn your passion against you and exploit your “will to win” to sell you products and services you don’t need. At best, these interventions will waste your limited resources; at worst, they’ll get you injured, sick, or banned from competition. Work with your coach and a health professional to make good decisions, and above all, be skeptical. Keep an open mind but not so open that your brains fall out.