You know how they say we only use 10 percent of our brains? Well, there’s also a cap on how much muscle you can use in a given set, and some of that is governed by your gray matter. The number of muscle fibers that we can beat down and regrow is inherently limited by our size, genetic makeup and training level. But by enlisting your brain and the neural network it controls, you can summon more muscle fibers into play on each rep, greatly accelerating your gains in the gym.
1. Master Post-Activation Potentiation
Baseball players have been doing it forever. Think swinging a weighted bat in the on-deck circle is just ritualistic? No, it serves a purpose. By wielding a heavier implement before walking up to the plate, the brain is wired to fire muscles faster, which leads to greater bat speed. A study published in the Journal of Strength and Conditioning Research found that sprint performance in rugby players was improved after performing a heavy set (three reps at 90 percent of your one-rep max) of barbell squats. This works for building muscle, as well. By bench-pressing or squatting a weight that is 90 to 95 percent of your 1RM right before your working sets of, say, eight to 10 reps, your brain will have called more muscle into play, allowing you to move more weight more efficiently for more reps.
2. Get Unilateral
Research shows that you’re able to produce up to 20 percent more force with a limb that’s training solo. This means that if you could leg-press 300 pounds for 10 reps, you could reasonably expect to do a single-leg press at 180 pounds for that many reps. Researchers theorize that your brain knows more force is required to complete a familiar movement without the aid of the opposite limb and recruits more muscle to complete the task. A bonus? Many single-limb exercises allow you to self-spot through tough reps.
3. Move Faster
It’s easy to get stuck in a comfortable pace on all your reps — two seconds down, pause, two seconds up, for example. But if you’re not blasting through the positive, or concentric portion of the lift, you may be limiting how much total muscle you use. Some research suggests that simply thinking about moving the weight faster — even if it’s heavy and moving at what feels like a snail’s pace — can help your brain activate more total muscle fibers. So focus on exploding on each rep and then lowering it under control.
4. Perform Agonist-Antagonist Supersets
Another gem the lab coats have long known about is that a muscle is stronger when it’s trained immediately after its antagonist. This is why opposing muscle group supersets — think chest/back or biceps/triceps — are not only effective but also advisable if you want to use as much muscle as possible.
5. Stop And Go
Your muscles actually produce the most force when they’re not moving at all. Research in the Journal of Neurophysiology showed that isometric contractions recruit more motor units (thanks, brain) than concentric or eccentric contractions. As with No. 3, simply attempting a greater effort — like trying to move an unmovable object or pressing your hands together as hard as possible — can force your brain to call in reinforcements. You can use isometrics ahead of a big lift to prime key muscles to produce more force, or you can use them as a finisher, roping in whatever muscle fibers may have gone unscathed from the earlier work.