Sports Supplements and Vampire Claims

You are a middle-aged male. During your annual physical, a few tubes of blood were withdrawn.  A week later at the follow-up, your doctor remarks, “Only one of the results from your blood test merits discussion. Your testosterone values were low. I’d like you to start taking a new drug, derived from the urine of pubescent chimpanzees. It’s called Primerin. It’s non-hormonal, very safe, and it will bring your testosterone values into the normal range. It works by 'coaxing' your body’s own testosterone production.”

“Does it do anything else, like increase my muscle mass or strength, or enhance my erectile function or sex drive?” you ask. The doctor replies, “Well, usage of testosterone itself, as the hormone, can induce these changes in a notable proportion of men with low testosterone values but Primerin hasn’t yet been tested to determine if it, too, can do this. I would anticipate Primerin to improve or enhance these areas. Among the 30 or so patients that I have prescribed it for, one patient claims to have gotten stronger. Another experienced a stronger sex drive.”

Would you be inspired to pay for this prescription?

Let's focus on what consumers can see in the mirror and measure in the gym. For decades, changes in surrogate markers or hormones circulating within the blood have been exploited as evidence of efficacy. “Reduces lactic acid” is inferred to mean “enhances muscular performance.” “Increases nitric oxide production” is stretched to convey “increased muscle blood flow”—even though every published clinical trial evaluating “nitric oxide”-positioned sports nutrition products shows zero increases in muscle blood flow or subjectively reported “muscle pump."

Furthermore, dozens of clinical studies have demonstrated that certain proteins, amino acid combinations, or even protein and/or amino acid-centric dietary ingredient cocktails, can increase blood and muscle biopsy-determined increases in protein synthesis short-term (i.e., two- to six-hour time intervals after exercise). Other studies choose to focus on indirect measures of what fuels are burned during exercise, or even at rest.

How many of these studies have extended the duration of evaluation beyond a snapshot of a few hours to a full length movie, lasting weeks or months, measuring consumer-relevant outcomes: increased strength, speed, power, endurance, muscle mass, or fat loss? Very few.

Many assume that if fat burning is elevated for a few hours then “…fat will be ripped off my body over the next month.” The story goes that if you are making more protein the few hours after exercise then, “…I will become bigger, stronger, and faster in a few weeks of using this protein/amino cocktail than if I had just drunk milk or eaten soy burgers.”

Most enchanting is the “androgen sorcery,” showing elevations in this or that male hormone and not choosing to examine parameters that a consumer would really like to see (e.g., anatomical or physiological effects). If both were independently tested, would you buy a car with 35 percent higher fuel burn efficiency inside the engine or one that attains 55 miles per gallon highway and has faster acceleration than a Ferrari?