In 2010, researchers from McMaster University, in Ontario, Canada caused a bit of a commotion when they published a study showing a single resistance exercise workout performed at 30% 1RM was every bit as effective in stimulating muscle protein synthesis as loads lifted at 90% of 1RM (both performed to failure).
In fact, the 30%1RM condition resulted in a more prolonged muscle protein synthetic response with a greater elevation of myofibrillar protein synthesis rates than the 90% of 1RM condition at 24h after exercise.
These results would suggest lifting very light weights that are only 30% of your 1-rep maximum is more effective at stimulating muscle growth than lifting much heavier 90%RM weights. This caused a lot of excitement in bodybuilding magazines and Internet forums, but yours truly smiled knowingly, poured himself another glass of San Vittoria, and went back to downloading New Order remixes from Soundcloud (100% free and legal, thank you very much).
The reason for my distinct lack of excitement was that, having read several squillion research papers over the years, I long ago learned there’s a big difference between short-term and long term studies. There are a lot of things you can prod the body into doing after a single exposure to a certain stimulus, but maintaining that same response over a period of weeks, months or years is often an entirely different proposition. If the McMaster results were to hold up over the long-term, it would mean that lighter weights performed for higher reps were in fact more effective for stimulating muscle hypertrophy than heavier weights. While I certainly believe higher reps have their place in hypertrophy training and are under-appreciated by many trainees, to claim they are in fact superior than lower reps pretty much contradicts the entire empirical history of weight training.
What we needed from the McMaster Uni researchers was a paper in which they tested their 30%RM versus 90%RM protocol over the longer term. And then measuring actual muscle growth and strength gains over that period, as opposed to temporary spikes in muscle protein synthesis. Because at the end of the day, you go to the gym to build muscles impressive enough to make women yell "woohoo!" from passing vehicles and to nudge their friends so hard when you strut by that they spill their Midoris. Yeah, don't give me that line about lifting weights for self-improvement and health and bone density and all that bollocks, this is Uncle Anthony you're talking to. I know why you really go to the gym. And while I'm dazzling you with my powers of clairvoyancy, let me tell you I also know you want muscles strong enough to lift heavy stuff with ease, causing your mates to be greatly impressed and the girl of your dreams to purr "Gee, you're so strong!", right before you hoist her onto your shoulder and carry her off into a golden sunset to live happily ever after.
Regardless of what a worthy marker for hypertrophy it may constitute, no-one really give’s a rat’s posterior how high you can spike your muscle protein synthesis rates. No-one ever pulled a tasty hottie with the line “Hey honey, did you know that by modifying the percentage of one-rep max I use in my resistance exercise workouts I’ve been able to elevate my post-workout muscle protein synthetic rates by 38.65 percent? Pretty cool, huh?”
Heck, that’s only slightly less pathetic than “Um, can I buy you a drink?”
Anyway, in April of this year, the McMaster lads gave us exactly what we wanted - a paper showing what happens when heavy weights/low reps and light weights/high reps are compared over the longer term.
This Is The Subtitle For The Next Section – I’d Put Something Catchy Here But It’s Early In The Morning, I’m Stuck For Ideas And I’ve Got Lots Of Other Stuff To Do
In their follow-up study, the researchers recruited eighteen men (average age 21) and made them do unilateral (one leg) leg extensions to failure, 3 times per week, for 10 weeks. Yeah, I know, leg extensions are a rather wussy exercise but hey, that’s what the researchers chose, so let’s run with it for now (I’ll explain later how parts of this study have already been confirmed by researchers who employed non-wussy exercises like squats).
At the start of the study, each leg of each participant was randomly assigned in counter-balanced fashion to one of three possible unilateral training conditions:
-one set of knee extension performed to voluntary failure at 80% of 1RM (80%-1);
- three sets of knee extension performed to the point of fatigue at 80% of 1RM (80%-3);
- three sets performed to the point of fatigue with 30% of 1RM (30%-3).
Each participant trained both legs and was therefore assigned to two of the three possible training conditions. At the start of the study, all the participants could squeeze out at least 9 reps with the 80%RM weight and 30+ reps with the 30%RM weight.
Immediately after each training session subjects consumed a source of protein (PowerBar Protein Plus, 360 kcal, 3.5g leucine, 30g protein, 33g carbohydrate, 11g fat) in conjunction with 300ml of water to standardize the postexercise meal and to maximize the training adaptations (there is a wealth of research showing that post-workout ingestion of high quality protein and quickly absorbed carbohydrates is highly beneficial when it comes to maximizing the results of your training regimen. And before I get the usual 15 million emails all asking “Anthony, I know you’re a busy man but can you set aside everything else you had planned for today and post an elaborate, painstakingly presented breakdown of this research?”, the answer is…ugh. For those of you who are proud owners of The Fat Loss Bible, you may kindly open Chapter 15 and get the info. For those of you who don’t have FLB – buy it, you stingy sods. Hey, I just bought a dog who eats almost as much as I do, so I could do with the extra funds).
The researchers made pre- and post-training measures of strength, muscle volume by MRI, as well as pre- and post-training biopsies of the vastus lateralis (one of your thigh muscles, Google it), and a single post-exercise biopsy one hour after the first bout of exercise, to measure signalling proteins.
So what happened?
I’m so glad I asked.
Muscle Hypertrophy. After 10 weeks of training, the quadriceps muscle volume increased by a statistically significant degree in all groups, but the 80% x 3 sets and 30% x 3 sets protocols showed more than double the average hypertrophy of the 80% x 1 set condition (80% x 3 = 7.2%, 30% x 3 = 6.8%, 80% x 1 = 3.2%).
And so the hypertrophy findings of this study indicate that while multiple sets of leg extensions at 80%RM produce much greater hypertrophy than single sets of the same weight, there was little difference in hypertrophy between thigh muscles subjected to 3 sets of either 80%RM or 30%RM.
Strength Increases. The increase in 1RM strength was greater in the 80% x 1 and 80% x 3 conditions compared to the 30% x 3 condition. This is in agreement with other studies, utilizing squats and leg presses, that also found heavier weights to induce greater strength gains when compared to light weights performed at higher repetition ranges[3-5].
So if it’s strength you’re after, then keep lifting the heavy stuff. All the Olympic lifters among you, who’ve all but forgotten what it’s like to perform a set of anything more than 3 reps will be saying “no sh!t Sherlock/Einstein/Anthony!” Well, I prefer Anthony, but Einstein will work (Sherlock is a bit too tweed coat/cigar pipe for my liking, thanks). As anyone who’s ever nestled under both a 200lb bar and a 500lb bar then walked it out of the rack to begin squatting will know, lifting heavy weights just ain’t the same as lifting light weights, regardless of how much “burning” you feel and how many ugly grimaces you make while repping out with the lighter weight.
As the researchers stated:
“These results suggest that practice with a heavy relative load is necessary to maximize gains in 1RM strength of the trained movement. These observations are in line with previous work which has shown that strength gains are specific to the movement that is trained and strength gains are due to a combination of muscle hypertrophy and neural adaptations”.
Muscle signalling proteins. The researchers didn’t measure (or at least report) muscle protein synthesis in this new paper, but they did report changes in associated signalling proteins such as Akt, mTOR and p70S6K. Levels of these signalling proteins post-workout pretty much showed no relation to the observed hypertrophy. For example, the only difference noted was that p70S6K phosphorylation (a science geek word for “activitation”) was elevated 1 hour post exercise in the 80% x 1 and 80% x 3 groups, but not 30% x 3. Phosphorylation of Akt was not elevated in any of the conditions. mTOR phosphorylation was elevated above rest at 1 hour post exercise in all conditions.
Take-away points from this article:
- Don’t be afraid of high reps. They won’t cause your muscles to wither away, leaving you with the physique of a meth-addicted vegan.
- Light weights and high reps don’t cut it for strength development. If you only care about strength, or performing more than 5 reps per set tends to have a strong sleep-inducing effect on you (not good when you have several hundred pounds perched on your back) then breath yourself a big sigh of relief – life ain’t gonna end because you avoid high rep work.
Copyright © Anthony Colpo.
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