Milo and the Bullsh**
Progressive Overload is an outcome of adaptation - not the cause of it
Yes this is AI. No known images of Milo of Croton exist…
I’ll cut right to the chase here:
Most folks in this industry fundamentally misunderstand how progressive overload works.
We’ve talked around this idea quite a bit on both the podcast and in some of our other long-form content, so I figured it was high time to dedicate an entire article to it - if for no other reason than it gives us something solid to reference in future discussions around this same topic.
Because trust me…no matter how many times we say it, people still don’t understand how progressive overload actually works.
Milo and the Bull
If you’ve been to a strength and conditioning conference, sat through a strength and conditioning brief, or even watched a strength and conditioning video on YouTube, you’ll have inevitably come across some version of the Milo and the Bull story.
For the uninitiated, here’s a random YouTube video that popped up after I searched (as if to prove my point): “progressive overload.”
The story is attractive in it’s simplicity. A legendary Greek wrestler, Milo of Croton, randomly decides to pick up a calf and carry it across the field every single day. The calf, as calves tend to do, grew bigger and bigger until becoming a full-sized bull. Milo, having exposed himself to progressively heavier weight, got stronger and stronger. His exploits continue to influence the fitness industry to this day.
The moral of the story: as the calf got heavier, Milo got stronger. Thus, as the barbell gets heavier, so too may you grow stronger. In fact, let’s add 5lb…every week…ad infinitum.
The problem is, the story is backwards.
Milo and the Bullsh**
Milo couldn’t keep carrying the increasingly heavy animal simply because it got heavier. He could continue carrying the animal because his capacity was adapting fast enough to accommodate the increasing demand.
What we have here is what’s known as “reverse causality.” Reverse causality happens when we assume that X causes Y, when in reality, Y is causing X. To illustrate the point, let’s consider a totally unrelated but quite common example involving Income Levels and Happiness.
An observational study might find a strong correlation between high income and high life satisfaction. Instead of money directly causing happiness, being happier and more stable may lead to better work performance, higher productivity, and consequently a higher income.
Now, I don’t know how much money Milo made. Nor do I have a good sense of whether or not he was a happy person. What I do know is that the bull getting heavier isn’t what made him stronger.
Getting stronger allowed him to pick up a heavier bull.
Sit with that for a minute and think about the implications. It initially reads as somewhat of a semantic argument. Does it really matter what causes what? Who really cares?
Why This Is Important
Getting the causal direction wrong changes how you train people.
If you believe that simple progression (i.e. adding weight each week, reducing run times, etc) is what causes adaptation, forced progression becomes the objective of the program. This approach is almost synonymous with “programming” as we all know it. Test a supposed 1RM, determine % increase week-to-week, and anticipate a new 1RM X-weeks from now. Rinse and repeat. More weight. More reps. More sets. More miles. Faster pace. Beat last week. The spreadsheet says 225 this week because you did 220 last week.
I would argue that the real objective of a training program is to provide just enough stimulus to drive adaptation.
The ability to progress is evidence that adaptation has occurred, not the mechanism by which it happens.
This distinction matters in a few big ways:
It prevents unnecessary escalation: If 3×5 at a given load is still producing a useful stimulus, you don’t need to manufacture “progress” just to satisfy the spreadsheet.
It explains why training doesn’t need to change every session: performance involves some signal, but a lot of noise. Sleep, stress, nutrition, preference, etc can obscure the picture. Failure to improve on last week’s numbers doesn’t automatically mean the program isn’t working
It makes autoregulation make sense, and this is exactly why we use it so heavily: “3×5 @ RPE 8” allows the external load to emerge from the athlete’s current capacity rather than forcing capacity to conform to a predetermined load.
It separates stimulus from performance: Training is what you do to cause adaptation. Performance is one way adaptation eventually expresses itself.
But perhaps the biggest take-home point from my argument is this:
Capacity should pull training forward. Training shouldn’t constantly push capacity forward.
Closing Thoughts
If your athlete is adapting to the training you’re prescribing, progression will emerge naturally. Today’s RPE 8 load becomes easier. The same pace on a run generates a lower heart rate. They’re able to tolerate more work within the same amount of time. Regardless of how you choose to measure it, the point remains the same: eventually, you’ll have to increase the demand just to preserve the same stimulus.
Milo needed a heavier bull to continue getting stronger. He didn’t get stronger simply because the bull kept getting heavier.
You’re not adding five pounds because adding five pounds makes you stronger. You’re adding five pounds because you’ve gotten strong enough that you need five more pounds to create the same relative challenge.
Progressive overload isn’t how you force adaptation. It’s how you keep up with it.