In this column, we believe in randomized, double-blinded, placebo-controlled trials. Others may start popping a new supplement because their friend said it made them feel good, strap on the latest wearable device because logic suggests the information it provides should be useful, or start doing Norwegian double-threshold workouts because Jakob Ingebrigtsen is really fast. But we wait for solid scientific evidence, preferably from multi-year studies with large sample sizes synthesized in meta-analyses.
In truth, though, this approach inevitably leaves a lot of questions unanswered. Good luck running a trial in which half the participants are randomized to run 100 miles a week for the next 20 years, while the other half do no exercise whatsoever. As a result, many of our key insights about how to optimize health and improve performance come from other types of sources, including what a new article in Comprehensive Physiology calls “experiments of nature.” Mayo Clinic physiologist Michael Joyner and his colleagues surveyed some of the most important natural experiments in the history of exercise science, offering…
