This is a little bit of an odd article. I’m going to start by discussing low load (LL) training then do a truncated ‘research review’ and use that to go into what amounts to an opinion piece about current research studies on weight training.
What is Low Load Training?
LL training is a relatively ‘new’ (by which I mean in the last 5-10 years) type of training it. During low load training, subjects lift a fairly light weight , typically in the realm of 30% of 1 repetition maximum to failure. Various studies in varying populations have shown that this generates the same muscular growth as heavy load (HL) training at 80% of max. A typical study will compare 3 sets at 30% of max to 3 sets at 80% and both groups get the same basic growth.
Admittedly this seems surprising given what we think we know about muscle growth. But as I discussed, it may not be. Simplistically, a set taken to failure, almost irrespective of the load on the bar ends up causing all fibers to be recruited and fatigued. In premise we might expect similar growth.
Now there is some very early indication that the growth may be fiber specific. That is low load training may be generating Type I fiber growth and high load Type II. Much more work is needed on this topic.
The point stands, both LL and high load training seem to generate the same growth. That doesn’t make them identical in terms of their effects. Low load training doesn’t generally increasing maximum strength as much as heavy training. This makes sense based on specificity alone. It also won’t be beneficial for bone mineral density (BMD) since the absolute load isn’t sufficient.
Certainly it’s kind of neat from a physiological sense to be sure. But I don’t think it’s generally worth much in a real world context. And I will still argue that there is an “effective” hypertrophy zone, irrespective of this data set.
Problems with Low Load Training
There are several problems with low load training (and these comments apply to blood flow restriction as well). One is that it’s not very time efficient. On average folks might get about 30 reps at 30% of max and 8 at 80%. Three sets of each means 90 reps vs 24 or so. Triple the number of repetitions to get identical growth and no benefit on strength or BMD.
Of course, the nature of the training limits it to fairly simple movements. Nobody is squatting 3 sets of 30 at 30% of max. Or deadlifting the same. Leg press, leg extension, machines, sure. Most compound movements….not a great plan.
This isn’t an inherent deal breaker. I think there’s too much emphasis on “compounds rool and machines drool” in this macho driven industry to begin with. But it’s a consideration.
Low load training, like BFR, also hurts like hell. The buildup of acid by products is immense and what’s often left out of study discussions is people throwing up during the workouts. So it’s more painful for no better growth and no impact on maximal strength or BMD. So far it’s not looking good for low load training and I don’t think it’s worth doing for most people.
Is Low Load Training Useless?
So is low load training useless? I wouldn’t go that for. Rather, I think it’s uses are very limited.
Certainly when someone has a joint injury and needs to train the muscles while limiting absolute joint loading, LL training (or BFR) can be very useful. It lets you train the muscle without overstressing the joint.
If someone has reached a point that they have stacked a machine and can’t add weight, LL also allows them to bring the weight way back and get a similar training stimulus. Since this would generally be done on secondary movements (i.e. after heavier work), this is no big deal.
Of course, videos of both LL and BFR training look edgy as hell on Instagram. And that’s probably their most important use.
So no, I don’t think LL training is useless. I just don’t think it has much point outside of a few specific situations. Mainly Instagram.
Low Load Training “Research Review”
So the study I want to review came out in July of this year although it doesn’t seem to have reached full print status yet.
Dinyer TK et al. Low-Load vs. High-Load Resistance Training to Failure on One Repetition Maximum Strength and Body Composition in Untrained Women. J Strength Cond Res. 2019 Jul;33(7):1737-1744. doi: 10.1519/JSC.0000000000003194.
Yes, this means I’m drawing only from the abstract but it’s no big deal since my goal isn’t to really analyze the study in any sort of detail. This is just a lead-in to something else.
So the study took 23 untrained women and had them either do 30% of 1RM training or 80% of 1RM. Normally I don’t give a damn about studies in the untrained since it all works about the same. I don’t honestly care about this study particularly except for one little bit I’ll address below.
They tested their 1RM on weeks 1, 5 and 12 and did 2 sets to failure on weeks 2-4 and 6-7 and went to 3 sets in weeks 8-11. Leg extension, leg curl, military press and lat pulldown were the movements and changes in body comp were measured by DEXA (which doesn’t have to be blinded to begin with so I won’t bring that topic up).
Both groups improved 1RM the same which contradicts what I wrote above. But in beginners, everything improves 1RM about the same so it really doesn’t. Neither group had a change in Bone and Fat Free Mass or Fat Mass so neither training protocol was superior here. Meh to all of it since it’s in beginners and what you do really doesn’t matter much to begin with.
So why does this study matter?
So shortly after the paper was released, an addendum was released by the authors. It was simply data that was left out of the full paper, specifically listing the ranges of repetitions that the women got on each exercise at each intensity. As I mentioned above, on average you might see someone get about 30-35 reps at 30% of max and 8 reps at 80% of max but this can vary. And unfortunately I don’t have the average repetitions that the subjects did because it kind of doesn’t matter in terms of the point I’m trying to make.
So here’s the data and man does it fail the reality check.
So, focusing mostly on the 30% group. On leg extensions the range was 5 to 32 reps. The 32 is consistent with other work but who gets only 5 reps at 30% of 1RM? Military press is 2-32. Again, 32 is in range of other studies but how can you get only 2 reps at 30% of your supposed 1 rep max when that’s usually closer to 95%?
Then it gets stupid.
For leg curl, the range was 8 to 204 repetitions. Two Hundred and Four. At 2 seconds per repetition (I don’t know if tempo was controlled), that’s 448 seconds. Just shy of 8 minutes of leg curls.
And then the zinger, lat pulldown with a range of 7 to 448 repetitions. FOUR HUNDRED AND FORTY EIGHT. Again, at 2 seconds per rep, the subject did 896 seconds of work which is just shy of 15 minutes straight of lat pulldowns.
One thing occurs to me as I write this, and this isn’t in the video. Perhaps these rep numbers are meant to represent the 2 or 3 sets to failure added up. This would make the insanely high numbers more reasonable (448 reps in 3 sets is “only” 114 per set).
But I don’t think that can be the case because it would mean that someone only got 1-2 reps across 3 sets to failure in some movements. And that fails the reality check harder. There is also no way that the 80% rep ranges could be moer than one set.
So I have to assume that range represents a single set of repetitions and the ranges that were accomplished.
Do You Believe It?
Ok, does anybody reading this actually believe it? Because I sure as hell do not. Yes, fine, women are generally more enduring at submaximal intensities. But do you believe 448 reps at 30% of max. Or only 2 reps? I’m sorry, it’s an impossibility in either direction.
At 80% the numbers are much more reasonable overall but with problems. On leg extension the range is 1 to 16 reps. Ok, so if you tested 1 rep maximum (defined as the weight you can only lift once) and do 80% of that…who only gets 1 rep? Same for military press at 2-11 reps. Who can only do 2 reps at 80% of their 1RM? And actually it’s the same across movements. Leg curl 2-14 and pulldown 2-17.
And I just think in the big picture those numbers fail the reality check. And I think people reading this will agree with me.
What’s the Problem Here?
So what’s going on? One issue that I didn’t address in the video is this: the 1RM testing was likely a problem. Beginners 1RM can change with nothing more than practice and expressing a true 1RM takes a while to learn. So it’s possible that their 1RM was inaccurate, which would make the percentages inaccurate. Still. If you can do 100 lbs for a 1RM, how can you only do 1 at 80 lbs?
But outside of that, what’s going on? Which is what leads me into the big topic change.
Video the Workouts
And this was a long way to get to what amounts to an opinion piece. More and more I am seeing resistance training studies where I question what is actually being done. Or rather if what is being described in the paper is actually being accomplished.
Yes, I read the descriptions where the subjects were monitored and taken to failure at some tempo and range of motion or whatever. And I’m not saying that the researchers are being deceptive. I’m sure this is what their intent is. I am questioning if it is actually happening. In some cases, I don’t think the workouts are possible to complete at all.
For reasons of standardization, most claim to push the subjects to failure. But definitions of failure can vary (good studies are explicit in their definition). And the simple fact is that most people stop when it gets hard, not at true limit failure. True muscular failure is defined as the inability to complete another repetition despite giving maximum effort. Realistically, most trainees have never reached true failure. The average trainee in these studies hasn’t either.
And I think an easy solution to this would be to video at least some of the actual workouts and have them accessible with the online paper itself. If they can provide these endless supplemental data sets, it’s trivial to set up a camera phone and take video of one or more of the workouts. Data plans are cheap and Youtube can host anything.
If BMJ can do infographics now, research studies can show one or two videos of the actual workouts.
Show Don’t Tell
Because I don’t believe these results. I do not believe that someone can only get 1-2 reps with 80% of their 1RM. And I sure as hell don’t believe anyone did continuous leg curls for 7 minutes or lat pulldowns for 15 minutes with anything approximating a controlled tempo or technique even at 30% of max.
A simple video of the workout would help to identify if that is the case or not. To show what range of motion, tempo, effort the subjects actually used. Because without seeing that set done, I don’t believe these results for a damn second.
I don’t think anybody reading this does either.
Because simply I don’t believe these results. I don’t believe that anyone can squat 5X8-12 reps to failure on 90 seconds and do it with anything more than the bar by the end (damn, I told myself I wouldn’t bring that up). Ok, fine, it was “form failure” but that just means that the sets will be stopped many reps from failure. And evenmoreso on 90 seconds.
Hell, I want to see that these guys took even a SINGLE set of squats anywhere close to actual failure. I know that 99% of people reading this have never done it deliberately and neither did the subjects in that study.
In this vein another study compared 16 sets done once/week to 8 sets done twice/week. In the 16 set workout, the subjects did flat bench and flye for 8 sets of 8-12RM on a 60 second rest interval. The researchers defined failuer as an inability to complete a proper form repetition. And well…I don’t believe it. 8 set to failure on a 60 second rest interval? They would have been using the bar by the end as the fatigue accumulated unless they were simply superhuman.
Take Some Damn Videos
And it goes on and on like this with studies claiming to put subjects through workouts that anybody in the real world knows can’t be completed at all or with any real quality. Which raises questions as to the validity of the results.
And in my opinion, a video of one or two of the workouts would readily show what actually happened.
And without going too hardcore on this, let’s just say that I think that videos of this nature might be….illustrative.