New strength training protocol provides new insight in how we build muscle

For those of us dreaming of packing on a little extra muscle, or just hanging on to what we’ve got, there was tantalizing news at the American College of Sports Medicine’s annual conference in San Diego earlier this month.

One of the “paper of the year”, chosen for their impact and significance for research, promote a new and exceptionally effective strength training protocol called the 3/7 method. It’s the latest in a long line of supposed muscle-building breakthroughs, and the good news is that it works. But the more interesting question is why it works and what that tells us about the real keys to building muscle.

The article originates from a meeting between a Swiss athletics trainer and a Belgian neurophysiologist. Jean-Pierre Egger was a two-time Olympic shot putter and is the trainer of multiple world champions, including four-time Olympic shot put medalist Valerie Adams. He told Jacques Duchateau, a researcher at the Université Libre de Bruxelles, about a new approach he had been using that allowed his athletes to maximize strength gains with less training time and effort.

Duchateau decided to test this new protocol in his laboratory. The 3/7 method, originally developed by French strength coach Emmanuel Legeard, involves lifting a weight about 70 percent of your one-rep max (or, equivalently, a weight you could lift about 12 times before failure). You lift it in five sets of 3, 4, 5, 6, and 7 reps, with just 15 seconds of rest between each set.

The protocol interested Duchateau because it seemed to combine the best of two different ways of building muscle. The relatively heavy weight puts mechanical stress on the muscle fibers, and the short rest period deprives the muscles of oxygen and imposes metabolic stress. Duchateau believes that each of these factors independently triggers muscle growth.

the award-winning paper, which Duchateau and colleagues published in Exercise and Sport Sciences Reviews, summarized a series of experiments that pitted the 3/7 method against various other protocols for the bench press. For both strength and muscle growth (but not explosive power), he overcame 4 sets of 6 reps with 2.5 minutes rest between sets and produced similar results to 8 sets of 6 reps, all with the same weight.

The key advantage, as both Egger and Duchateau point out, is efficiency. A single exercise with the 3/7 method takes about 5 minutes, compared to over 20 minutes for 8 sets of 6 reps.

But is the 3/7 approach better than the alternatives, or is it just different? If it’s efficiency you’re after, a Dutch company called fit20 offers a once-a-week program that involves just one set of 4-6 ultra-slow reps of each exercise. A multi-year analysis of nearly 15,000 people using that system, published by Solent University researcher James Steele, found typical strength gains of about 30 percent after a year.

As for the supposed magic of combining mechanical and metabolic stress, McMaster University researcher Stuart Phillips, who coincidentally received the ACSM Citation for Significant Contributions to Exercise Science at this month’s annual conference, continues being skeptical. After all, he points out, track runners induce a lot of metabolic stress while doing interval training, but they don’t build massive leg muscles.

A study series by Phillips and others over the past decade has shown that many different exercise routines lead to similar increases in muscle and strength. The key common point: that you come close to (although not necessarily close to) momentary failure at the end of each exercise. Light weights, heavy weights, short breaks, long breaks – you can adjust the variables to your heart’s content whenever the end of the set feels tough.

The 3/7 approach definitely checks that box: If you’ve picked the right weight, you’ll fail the last two sets, says Duchateau. So if you’ve hit a plateau or are looking for some variety in your workouts, give the new method a try. Or, if you prefer, stick with your old method. Either way, Phillips says, the real magic ingredients remain the same: effort and consistency.

Alex Hutchinson is the author of Endure: Mind, Body, and the Curiously Elastic Limits of Human Performance. Follow him on Twitter @sweatscience.

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