Professional bodybuilders look like testosterone incarnate. Their arms are the circumference of an average man’s thighs. They have 10-pack cobblestone abs. And when they strike a crab pose, their striated muscles and bulging veins look like a Boston roadmap.

That’s why we asked Brad Schoenfeld, Ph.D.—a former natural bodybuilder who’s a top expert on muscle science—for his list of bodybuilding techniques that have stood the test of time. Add them to your own strength routine for a better workout and serious gains.

1. Accentuated Eccentric Sets

Bodybuilders trigger greater strength and muscle-building gains by focusing on the eccentric—or lowering—phase of heavy lifts like the deadlift, squat, and bench press. They can use more weight than their one-rep max by zeroing in on this portion of the lift, explains Schoenfeld.

The reason: Your muscles can handle more weight during the eccentric because they’re only slowing the weight against gravity. On the way up, however, they must push the weight against gravity, says Schoenfeld.

And even though you’re only performing half the movement with heavier weights, your body doesn’t know that.

“Sensors in your muscles pick up on the extra tension in your body,” says Schoenfeld. “Those sensors then incite the release of chemical signals that ultimately produce more muscle-building proteins.”

Schoenfeld recommends trying these muscle-draining reps at the end of a workout, rather than the beginning, so they don’t sabotage your strength.

Use it: Grab two spotters and try this with the barbell bench press, shooting for 120 to 140 percent of your 1-rep max. Lower the bar to your chest as slowly as you can. Have the spotters assist you in pressing the bar back to the top. Repeat 3 to 5 times.

 2. Drop Sets

Drop sets—also called descending set or strip sets—were a favourite of Arnold’s to build bulk. The method involves performing a set of any exercises to momentary failure, and then dropping some pounds and banging out more reps.

“Increasing the number of reps you do to fatigue increases the metabolic stress in your body, which positively affects muscle growth,” says Schoenfeld.

Scientists think that when your body senses a buildup of metabolites—the byproducts of the energy you use in your workout—it adapts by adding more muscle to the specific area.

Use it: Racking and unracking weight plates takes time, which can diminish the effects of the drop set. That’s why Schoenfeld recommends using a cable pulley system for an exercise like the cable row to build your back. “You just have to reset the pin, so you’ll keep moving efficiently through your workout,” he says.

Set a cable pulley to a weight that you can lift for only 8 reps. Your final rep should be extremely hard to complete, taking all of your effort to perform. Then quickly reduce the weight by 20 to 25 percent, and perform as many reps as possible.

 3. High-Rep, Light-Weight Sets

Bodybuilders sometimes go light to get big.

When you only lift heavy, you only hit your fast-twitch muscle fibres, not your slow-twitch ones. Now research is finding that training with lighter weights may increase the size of your slow-twitch muscle fibres due to more time under tension, says Schoenfeld.

Incorporating lighter weights into your program one day every week or two will help you maximize your muscles’ full potential.

Cranking out high-rep sets can also help you achieve an impressive “pump”—that swollen feeling that occurs when you increase the time your muscles are under tension. Your muscles become engorged with blood and have to stretch to accommodate the excess fluid, making them look bigger.

At the same times, this enhances protein synthesis—the process that helps promote muscle repair and growth after exercise—and decreases muscle breakdown that can occur over time, says Schoenfeld.

“Your cells have to adapt to the extra pressure by reinforcing the strength of their walls,” he says. The result: thicker, stronger, and bigger muscle fibres.

Use it: Try this technique with exercises that isolate one or two muscles so you can keep tension on the target muscle the entire time, says Schoenfeld. For example, do it with a biceps curl, triceps extension, or calf raise. Perform 20 to 30 reps with a dumbbell that’s about 60 percent of your 1-rep max. Repeat for a total of 3 sets.

 4. Paired Sets

Used by bodybuilders to maximize the amount of work their muscles can do, paired sets are similar to supersets—in which you perform two exercises that work different muscles back-to-back without resting.

However, supersets typically attack different limbs or body parts—like the chest and the glutes. Paired sets, on the other hand, work opposing muscles within the same group—like the quads and hamstrings, explains Schoenfeld.

These duos activate a phenomenon called reciprocal innervation. “There’s some evidence to suggest that when you work your quads, for example, you can increase the ‘readiness’ of your hamstrings for the next exercise,” says Schoenfeld.

When you work muscles that oppose each other, contracting one means lightly stretching the other, or at least preventing it from contracting. “That leaves the muscle rested and able to produce greater force when it must work,” he says. And when your muscles work harder, you create more microtears in your muscles. Your muscles grow bigger and stronger as your body repairs these tears.

Use it: Hit your quads with 8 to 12 reps of the leg extension. Then immediately hit your hamstrings with 8 to 12 reps of the straight-leg deadlift. Do 3 sets total.

 5. Work-Stretch Sets

Making your muscles pop could be as simple as stretching them out. After performing a set of an exercise, you’ll use the weights to lightly stretch the targeted muscle in its extended state.

Bodybuilders use this as a strategy to incite a process called hyperplasia. This causes your muscle fibres split and become new, independent fibres. You’re essentially turning one muscle fibre into two, Schoenfeld says. Though he notes that more research needs to be done in the lab before scientists can definitively determine whether or not the extra muscle growth is actually due to this phenomenon.

Most exercises induce a process called hypertrophy, which causes your existing muscle fibres to increase in diameter, says Schoenfeld. Hyperplasia, though, increases the actual number of fibres you have in your muscles, he says.

Use it: Perform 8 to 12 reps of the dumbbell fly on a bench. One your last rep, finish by holding the dumbbells out so they pull your arms down toward the floor a couple inches, stretching your pecs, shoulders, and biceps for 30 seconds. Repeat for a total of 3 sets.

But you have to be careful, Schoenfeld warns. “If the weight is heavy or if you’re not cautious, you can do more harm than good—injuring a muscle, ligament, or tendon.” Stop immediately if you feel a tugging, pulling, or burning sensation that’s unpleasant.