We’ve all heard that training with heavy weights for lower rep ranges will produce two results: strength and size. That pervasive truth is a bit simplified — the true science goes beyond that — but one valid reason for this general direction is so the body learns to make best use of its biggest, strongest and most quickly fatiguing muscle fibers. Targeting your fast-twitch fibers specifically will produce some of the most direct effects on your body composition and performance because they help you lift more weight, produce more power and grow more muscle.
Whether you’re a physique competitor, a competitive lifter, an athlete or someone who just wants to lean out and build muscle, you can benefit from a more strategic emphasis on your fast-twitch fibers. This can be accomplished via many different training methods, but we can boil things down to three key tactics that are almost universally effective for enhancing your fast-twitch machinery.
Method 1: Olympic Lifting
Olympic lifting — the snatch, clean and jerk and their many derivatives and variations — is the most explosive form of weight training you can do. It allows the body to accelerate maximum loads in a burst of power that lasts one to two seconds at most. It’s a testament to your absolute strength and power, and doesn’t involve traditional muscular fatigue but rather emphasizes central nervous system excitement. Because of this, the nervous system will more efficiently fire your fast-twitch muscle fibers, making them more responsive and involved in your normal weight training. Plus, being able to drop the bar after you complete the lift incurs no added muscle damage from eccentric reps, which can increase your workout volume and recovery.
Method 2: Plyometrics + Sprinting
Though they’re usually done unloaded, plyos come in handy when training for explosiveness, mainly because they incorporate a quick and repeated use of the stretch reflex. This is a key player for performance enthusiasts who need responsive, reactive muscles for multidirectional and/or explosive sports. Along the same lines, sprinting allows for an all-out max effort to be produced while incorporating the stretch reflex at basically every major load-bearing joint on each stride. These types of movements also emphasize fast-twitch fibers, primarily in the legs, which can translate to greater performance on traditional lifts such as squats, deadlifts and lunges.
Method 3: Heavy Compound Lifting
Doing a basic set of exercise for five or six repetitions with considerable weight will place considerable stress on the nervous system while also targeting your fast-twitch muscle fibers. The good news here is that playing with the tempo can make a world of difference as to which fibers are emphasized. The strongest ones are actually the type IIb fibers that are mostly involved during eccentric reps. That being said, slowing down those eccentric reps and following a 30X0 tempo (three-second negative, no rest at top or bottom and an explosive positive rep) may be just what the doctor ordered for increasing strength and tapping into your inner fast-twitch beast.
A combination of performance-based training and heavy, traditional weight training at specific tempos goes a long way toward achieving fast-twitch gains. Remember: These are advanced training tools and they absolutely demand a foundation of basic joint health and lifting technique. Beginners need not apply — yet — but those who adopt these practices will be the recipients of a bigger, stronger, leaner and overall more powerful physique.