Your musculature includes two types of fibers, slow twitch and fast twitch. Slow twitch muscles are recruited for endurance activities and don't tire out easily, but they can't produce as much force as fast twitch muscle fibers. Fast twitch muscles, used by your body during anaerobic activity, provide short bursts of force but tire quickly. Your genetics determines your ratio of fast to slow twitch muscle, but you can make the most of what you have through training.
Training Fast Twitch Muscles
If you're looking to gain explosive strength and muscle growth, or hypertrophy, you should focus your weight training on your fast twitch muscle fibers. Fast twitch muscles are more reactive and grow more quickly than slow twitch muscles. You're training your fast twitch muscles whenever you perform short bursts of intense activity, such as sprinting, weight lifting or throwing. When performing a bench press, keep things short and explosive with heavy resistance.
Bench Press Technique and Benefits
Bench pressing trains the muscle fibers in your chest, shoulders and triceps. Lie on a flat bench with the barbell rack positioned directly above your face. Plant your feet on the floor to either side of the bench and place your hands shoulder-width apart on the barbell, palms facing forward. Lift the barbell off the rack and position it with your arms extended directly toward the ceiling. As you inhale, slowly lower the bar toward your chest. Push the bar back toward the ceiling as you exhale. Avoid arching your lower back during the exercise and always have a spotter ready to help you with the weight.
Bench Pressing for Fast Twitch Muscle
Performing a bench press naturally trains fast twitch muscles, but you can modify your technique to maximize the fast twitch benefits. Short bursts of speed and power, as well as eccentric, or lengthening, contractions, both stimulate your fast twitch muscle fibers. When bench pressing, slow down the eccentric, or downward, portion of the lift to four to five seconds before pushing the bar back up explosively. Alternately, perform an eccentric-only set by slowly lowering the barbell to your chest and having your spotter help you return it to the starting position. When performing an eccentric-only set, you can add more weight than if you were performing a traditional bench press.
Repetitions, Sets and Rest
The number of repetitions and sets you perform, as well as how long you rest between each set, contributes to the type of muscle fiber activated. To focus your bench press efforts on your fast twitch muscles, perform two to six sets of four to eight repetitions with a barbell heavy enough to fully fatigue your muscles by the final repetition. Fast twitch muscle fibers tire quickly. Let your muscles recover for two to five minutes between sets.
- Northeast Texas Community College: Muscle Fiber Types/Body Types
- Coaching Science Abstracts: Evaluation of Strength Training Concepts
- Grand Valley State University: Muscle Growth
- American Council on Exercise: Barbell Bench Press
- Journal of Sports Sciences: Differences in Activation Patterns Between Eccentric and Concentric Quadriceps Contractions
- Peak Performance: Fast-Twitch Muscles
- American Council on Exercise: When Strength Training, Is it Better to Do More Reps With Lighter Weights or Fewer Reps With Heavier Weights?