From: Daniel Duane, Fitness Crazed (edited)
Athletic coaches the world over know how to get people fit: every week for several months, take a few short runs midweek and a single long run on the weekend. Make sure the long run gets a little bit longer each time. Before you know it, you’ll be able to run 26.2 miles.
This works because the human body is an adaptation machine. If you force it to do something a little harder than it has had to do recently, it will respond — afterward, while you rest — by changing enough to be able to do that new hard task more comfortably next time.
This is known as the progressive overload principle. All athletic training involves manipulating that principle through small, steady increases in weight, speed, distance or whatever.
Ignore supposed research that tells you that you should do intense, brief workouts instead of long ones.
When I found myself 40, fat and weak, I paid special attention to exercise science articles about cutting-edge studies that claimed you should do intense, brief workouts instead of long ones.
I hired personal trainers who taught me to avoid barbell lifts like squats in favor of tricky new exercises on wobble boards and big inflatable balls to stimulate my body’s core. I learned about the science of muscle confusion which claims that you change routines constantly.
Nothing worked until I found “Starting Strength: Basic Barbell Training,” by Mark Rippetoe. The program sounded like an unscientific joke. It called for three workouts a week, built around five old-fashioned lifts: the squat, dead lift, power clean, bench press and standing press.
However, I followed Mr. Rippetoe’s instructions and did three sets of five reps in the squat, dead lift and standing press. Then I went home and drank milk. Two days later, I did three sets of five in the squat and the bench press. I repeated this basic pattern, alternating the dead lift with the power clean, for a year, adding a little more weight to the bar in every lift, during every session.
I was able to lift a tiny bit more every single time. It was a marvel to me and raised a question: If all the latest cutting-edge scientific research says that outdated barbell movements have to be updated with core stability tricks and then integrated into super-short high-intensity muscle-confusion routines, how come none of that did much for me, while the same five lifts repeated for a year caused profound structural changes to my body?
The answer: there are no cutting-edge scientific studies.
There’s not a lot of research money to fund applied studies. On matters as simple as how many sets and reps best promote muscle growth, we can’t nail down the answer.
Physiologists study questions like the molecular signaling proteins that regulate skeletal muscle adaptation. Then, everybody in the fitness industry grabs onto this basic science — plus the occasional underfunded applied study with a handful of student subjects — and twists the results to come up with something that sounds like a science-backed recommendation for whatever they’re selling.