I’ll cut right to the chase: absolute load absolutely matters. But we still have a lot to learn about this.
Defining Terms
Let’s make sure our definitions are clear before proceeding further. When I refer to absolute load, I’m talking about the weight on the bar, measured in pounds if you love freedom, or kilograms if you’re a dirty commie. 225 lbs, 200 kilos, or colloquialisms like “5 plates” (which equals 495 lbs) are absolute load references.
When I refer to percentages, I’m referring to a percent of a specific lifter’s 1 repetition maximum. So if a given lifter can deadlift a maximum of 500 lbs for 1 maximum effort rep, then 90% is 450 lbs, 80% is 400 lbs, 70% is 350 lbs, and so on.
When and How it Matters
Something I see out in the wild, both in the gym and online, is advice from very strong, advanced lifters that might be great for people in their own cohort, but isn’t very good for novices or early intermediates. It often involves using relatively low percentages, as defined above, for volume work, and purposely leaving a rep or three in the tank so as not to go too close to failure and elicit large doses of fatigue.
It’s not too hard to understand why this is important for a strong, advanced lifter. Let’s say our theoretical advanced lifter has an 800 lb max deadlift. 800 lbs is a hell of a lot of weight, in the absolute sense, and lifting close to that much on a regular basis would tire the hell out of almost anyone. Such a lifter can take a weight that’s a relatively low percentage, like 60%, and still do some productive work with it. Some of his work will also need to be heavier and at a higher %, but by virtue of having an 800 lb max, even a low % like 60 is still 480 lbs. That’s more weight than most people who train will ever lift in their entire lives, much less the average person who doesn’t even train. It’s a lot of weight in the absolute sense, even though it’s a low %, and so it can still be used for some of that lifter’s work, and be productive.
Compare that to a guy with below average strength & athleticism genes who just started lifting 9 months ago at the age of 55. His current max is 275, so 60% for him is 165. There’s practically no way to do productive, useful strength work for this guy with 165 lbs. He could tire himself out doing it for multiple 20-rep sets, but it wouldn’t help him get any stronger, and would make him very fatigued. It’s only 165 lbs. It’s just not heavy or mechanically stressful to the human organism in an objective sense. So it’s not productive work. Source: tens of thousands of hours coaching thousands of people. I believe it’s raining when I see it with my own eyes, no matter what the weather report says.
Whereas the 800 lb lifter using 480 lbs for some of his work, will still be able to get something out of it because it’s 480 lbs. It’s heavy to the human organism in an absolute sense, even though he’s trained to be strong enough to where it’s easy and quick when he lifts it. So while his highly developed strength will require most of his work to be quite heavier, he can still add to his productive total work output even with weights in the 480 range.
Murky Practical Applications
The problem with this observation, which other coaches I know and respect have also made, is that its exact boundaries are murky. How heavy does it have to be before this effect kicks in? Is 315 heavy enough, even at a low %, to be productive work? 365? 405? We don’t really know. How much does it vary lifter to lifter? How many reps need to be done for it to be productive - does a 700 deadlifter using 405 (57%) need to do sets of 5, for it to be useful, or are multiple triples ok? Or does it need to be sets of 8? Can total reps make up for reps per set, i.e. if that same 700 deadlifter uses 405 for 7 sets of 3, is that similarly productive to if he does 405 for 4 sets of 5?
Lots of questions for which we only have estimates and experience to guide us. My sense of the formal literature is that equal volume is roughly equally productive if the weight/% are the same, but my own lifting and coaching experience suggest that, the further the weight is from the lifter’s max, the more it needs to be done a little closer to failure (obviously not truly close to failure, but a little closer) to be more productive. So in our example above, I’d rather have the guy do 4 sets of 5 at 405 than 7 sets of 3. But I’m not absolutely sure about this.
I would love to see good, high quality research in exercise science dedicated to answering interesting and practical questions like this, that coaches in the trenches observe consistently (if they’re looking), but for which a little more control of variables would be useful than is feasible in the gym.
Instead, however, we get gems like this one, that tell us that bench pressing on a swiss ball is just as good as a flat, hard bench for muscle activation. This doesn’t pass the piss test, much less the smell test. All it really tells me is that EMG-based muscle activation is probably not a very good proxy for productive training stimulus. Until the field improves by leaps and bounds, which I don’t currently see the incentives in place to make happen, I will continue to believe my own eyes that see the raindrops, instead of the weather report that tells me we have sunny skies.
I don't think it's absolute weight that really matters...until you are very strong.
We would see hard cutoffs and there would be no gains for newbies at all if there was an need for some absolute load. But we do see gains with only the bar in many cases.
I just think that the new lifter just has "fake" %'s. He cannot recruit enough muscle stuff (the technical term BTW) for his 70% to be my 70%, much less your 70%.
I think the reality is just that newbies need higher %'s and that strong people are closer to the real tolerances of their body and need lower %'s on average because they will break shit otherwise.