If you are a competitive distance runner or cyclist who is serious about your sport, this article has not been written for you. This highly informative discussion is intended for those people who have taken seriously the advice of doctors, physical therapists, exercise physiologists, and the popular media’s dutiful reporting on these sources of common misinformation about what kind of physical activity is best for your long-term health and continued ability to participate in the business of living well.
Endurance exercise is the most commonly recommended form of activity for health and “wellness.” Every time you see an exercise recommendation denominated in minutes, you are seeing a recommendation for long slow distance exercise — LSD, or “cardio” in the modern vernacular. Running, bicycling, rowing, or their health-club analogs on machines at the gym are what they mean when they say “exercise.”
Depending on who you listen to, 20 minutes per day, 3 hours (120 minutes) per week, or any permutation thereof as a prescription for fitness/health/wellness is the standard in both the fitness and health care industries, and getting stronger is always of secondary importance.
The endurance exercise approach ignores several basic facts:
1. Strength is the ability to produce force with your muscles against an external resistance, like those with which we interact in our environment as we go through our days, living our lives productively. And endurance exercise is directly antagonistic to strength, because an endurance adaptation occurs at the expense of strength.
The body’s basic response to a stress of any type is to recover from that stress in a way that makes it less likely to be a stress when next exposed to it. In other words, we adapt to stress by becoming better able to withstand it. This means that the adaptation to the stress is specific to the type of stress. An endurance stress is low-intensity and highly repetitive, meaning that each of the individual physical efforts that make up the run is easy — none of them are physically difficult from a strength perspective. If they were, you couldn’t do them over and over again for an hour. This means that the hard part is the cumulative effects of the run, not the strides themselves, which are easy.
Since the individual efforts that compose the run are easy, they do not depend on, nor are they limited by, the runner’s strength. Therefore, running cannot make you stronger, since it does not stress your ability to produce increasing amounts of force. Rather, it only depends on your ability to keep producing small amounts of force for an hour.
But more importantly, since running for an hour requires a different adaptation from the muscles, that adaptation will be favored by the muscles and will actively compete for precedence over a strength adaptation — especially if you’re not doing any strength training, or doing it wrong.
Quite literally, the more you run, the better you are at running and the worse you are at being strong.