Jason Karp, PhD, MBA

One of the biggest honors of my life was to give a @TEDTalks to share my idea worth spreading. ted.com/talks/dr_jason_karp_…

Among cross-sectional studies, average weekly mileage explains just 15-25% of variance in running performance, largely depending on performance level & race distance. Many runners who run 50 mi/wk run faster races than those who run 80 mi/wk, simply because they're more talented.

The workout itself is not really what matters. The runner’s response to the workout is what matters. And the same workout is not the same stimulus for two runners.

If we focus on the outside — making our physical bodies strong, resilient, and enduring — that changes us on the inside. ted.com/talks/dr_jason_karp_…

In the face of a lower-quality diet—perhaps one that includes donuts and lacks vegetables—exercise mitigates and, in some cases, even erases its effects, reducing your risk of disease.

Running eliminates the stress of life's problems, heightening enjoyment of the good things, at least for the precious moments we run. We can literally put space between ourselves & our problems, inserting clarity in the space & developing confidence to handle what is asked of us.

The more fit you are, the lesser the risk of developing the metabolic risk factors that cause heart disease and diabetes, regardless of what is on your dinner plate.

Not only does exercise prevent weight gain, body weight and BMI are directly proportional to the amount of exercise people do.

The difference between nutrition & exercise often overlooked is that, while bad nutrition & not exercising are both bad for health, with not exercising being worse, only exercise greatly improves health. Good nutrition only prevents harm or supports/moderates effects of exercise.

Running Form Myth 3: Increasing cadence reduces injury risk. Studies found increasing cadence acutely reduced biomechanical loading measures. Increasing cadence changes biomechanics, but doesn't reduce injury risk. Changing cadence can redistribute rather than eliminate loading.

Running Form Myth 2: 180 steps/min is ideal running cadence. Observations of elite runners showed many had that number, which turned into a prescription. Optimal cadence varies by individual, speed, & other factors. Each runner has preferred cadence that minimizes metabolic cost.

Running Form Myth 1: Heel striking causes injuries. Early studies linked heel striking to greater impact forces; barefoot-running gurus popularized idea. It's not inherently harmful. Foot-strike patterns redistribute loading; injury risk can't be inferred from that pattern alone.

What happens when your belief becomes what you think you are certain you know?

Beginning in the seventh grade, I became fascinated with time, specifically how fast it moves and how each year seems to go faster than the previous year. Runners, however, train by distance. But they shouldn't.

Most coaches know what workouts they prescribe. Far fewer know how or why those workouts work.

Stop asking, “What workout should I do?” Start asking, “What adaptation am I trying to create?”