Earlier this summer
I found myself sitting in on an exercise prescription lecture for second-year
Doctor of Physical Therapy students at my university. I’ll likely be delivering
this lecture next year, so I wanted to have a look-see at the material that was
currently being offered. Plus, I just love being that guy who sits in the back
of the room interrupting the professor to add his two cents every so often.
One of the things
that struck me during the lecture was the emphasis (or overemphasis, in my
opinion) on the one-repetition maximum (1RM). For those not familiar, a 1RM is the heaviest weight you can lift one time for a given
exercise.
(Note: if you’re
feeling fussy, you can differentiate between a “true” 1RM and a “technical”
1RM. True would be the heaviest weight you can lift, form be damned, just get
the weight up any which way. A technical max would be the heaviest weight you
can lift with perfect form.)
Devoting lecture time
to the 1RM isn’t unique to exercise prescription for physical therapy students.
1RM and the testing thereof gets a lot of attention in most exercise textbooks
and kinesiology curricula. This thorough treatment of the 1RM isn’t without
reason, of course. Tons of training parameters are based off of it.
Conventional
training wisdom dictates that if you want to train for a particular adaptation
(e.g. strength/power, muscle gain, or endurance), you do a specified number of reps that corresponds to a certain percentage of your 1RM. In addition, 1RM testing can be used to document
performance gains over time.
That’s all dandy,
but here’s my beef. Unless you’re a competitive powerlifter or an otherwise
advanced trainee, the process of
figuring out your 1RM is often unnecessarily painstaking, risky, and uninformative.
The number just
isn’t that important.
Nevertheless, since
the dawn of kinesiology instruction, many lectures and textbook chapters have
been dedicated to the determination of the 1RM. The process usually goes like
this:
1. Start off with a weight you know will be
easy, do a bunch of warm-up reps, and rest briefly.
2. Add some weight, do a few more warm-up reps,
and rest for a little longer.
3. Add some more weight, do a couple last
warm-up reps, and rest for a while.
4. Choose your first test weight, and do one
rep. If that was the absolute heaviest you could do, you’re done! Otherwise,
rest completely and proceed to Step #5.
5. Add a few pounds, and do one rep. If that
was the absolute heaviest you could do, you’re done! Otherwise, rest completely
and repeat this step.
See what I mean by
painstaking? All told, we’re looking at around 6-8 sets and upwards of 10-15
minutes. Tack on another 5-10 minutes if you’re testing two sides separately
(e.g. single-leg leg press). And that’s only for one exercise out of several
that are presumably going to be trained. Not to mention exposure to relatively
high loads for a person who may not tolerate them well. Is the risk
versus reward really worth it? Let’s see.
As I mentioned
above, the end-game of 1RM testing is generally to prescribe training loads.
For example, say I want to hit my trainee with a weight they can do for 12
reps. (I could just hit them with my prosthetic leg, but they probably wouldn’t
come back to me if I did that.) If I know their 1RM, there are at least half a dozen
conversion formulas and tables out there I can use to figure out what
percentage of their 1RM should allow them to perform those 12 reps.
The trouble is,
these formulas are only theoretical estimates -- estimates that may be accurate on average across a large
number of people but oftentimes not so much for the individual at hand. To
boot, the estimates get worse as the target number of reps increases. The calculation
might be decent for a set of 6 reps, but by the time you get to 12, it’s basically
a crapshoot. Not only that, but the estimates are also for one set, and I’m
often more interested in choosing a weight my client can handle for multiple sets.
The utility of
these estimates even varies between men and women. Anecdotally, women can often
perform a greater number of reps at a high percentage of their 1RM than men. Maybe
women have more endurance than men. Maybe women’s nervous systems inhibit them to
a higher degree as weights get heavy, causing them to underperform during 1RM testing unless they’re
highly trained. Who knows.
What I do know is
strength also fluctuates on a day-to-day basis for people regardless of their
sex based on a myriad of factors (sleep, stress, time of day, mood, training
status, etc.). This variability tends to make a 1RM from a previous day less relevant
-- and potentially a fool’s errand to go
chasing percentages off of.
All told, the time spent on 1RM testing could be better spent actually training or rehabbing and simply guessing loads. Anyone with half a brain and a few months of experience should be
able to estimate an appropriate weight for sets of 8, 10, 12, or whatever for the person in front of them, plus or minus a few
pounds.
Suppose you do over or undershoot the weight on the first set? You can easily adjust it for
the second set based on how many reps the person achieved, how the reps looked, and how they felt (i.e. "perceived exertion").1 Ask the person, "On a scale of 1-10, how difficult was that?" In general, for main lifts add weight if the answer is less than 8. For auxiliary exercises, add weight if the answer is less than 6.
If your guess was way off, you can even decide to relegate that first set to warm-up, and you’ve only "wasted" about two minutes. Whoop-de-doo. Please, tell me again how important 1RM testing is for calculating training loads.
If your guess was way off, you can even decide to relegate that first set to warm-up, and you’ve only "wasted" about two minutes. Whoop-de-doo. Please, tell me again how important 1RM testing is for calculating training loads.
Now, if you’re
using strength testing as a way to track performance gains, I’m totally on
board. My primary recommendation here would be to choose an
alternative that’s less risky than a 1RM, like a 10RM or 5RM (or maybe a 3RM,
in some cases). Not only do you avoid unnecessary exposure to super heavy loads,
but data points like these will also be a lot more relevant to people who train
more in that 5-10 rep range.
For serious lifters
or people who just like to geek out with numbers, I recommend making a table of
all your main lifts and your repetition maxes, as shown below. Each time you train,
endeavor to crush one of your previous bests.
Based on the above
discussion, it may sound like I’m saying no one should ever max out. I’m not. I’m
just saying you have to know when to do so (answer: infrequently; a few times
per year at most) and for whom to do it (answer: advanced trainees and people
who compete in lifting as a sport).
In a rehabilitation or training setting for a general population patient/client, there’s rarely a need for a 1RM.
With any luck, educational paradigms will come around to this truth soon.
1 I try to err on the side of undershooting. That way we're always adding weight rather than taking it away.↩
