How to build more fast-twitch muscle

(Image credit: Unknown)

Ever heard someone complain that they are hampered by a natural lack of fast-twitch muscle? Well it’s just not true. Whatever genetic hand nature has dealt you, you can increase your ratio of fast-twitch to slow-twitch muscle fibres by working out in a way that forces your body to adapt.

Everyone has two types of muscle fibre: fast-twitch, which generates explosive power, and slow-twitch, which generates less power but can work for longer. Having lots of slow-twitch fibres is ideal for endurance sports such as triathlon, but for explosive activities such as weightlifting, sprinting or football, you need more fast-twitch fibres.

How much you have of both types can vary dramatically, but even if you’re mainly a slow-twitch guy – probably due to a combination of genes and gradual adaptations – you can still turn yourself into a fast-twitch machine.

Less is more

The key is to encourage this adaptation while cutting back on counter-productive slow-twitch activities. You might love running 5K or 10K three times a week, but if you want to be more explosive, you need to focus on training that develops more fast-twitch muscle.

I recommend four workouts a week, alternating between upper and lower body. Do free weight-based compound moves as fast as possible, with five-minute rests between sets. Even if you’re not moving the weight very fast, by trying to lift it explosively you prompt the body to develop more fast-twitch muscle. The long rest periods allow for full metabolic and neural recovery – but they won’t make for an epic two-hour gym session.

Click here for more free-weight exercises

The aim is quality not quantity, with low rep ranges based on your experience – six to eight reps per set if you’ve been training for two years or less, four to six reps for two to five years and one to four reps for five years plus – and a maximum of ten working sets, split between three or four exercises.

People tend to focus on pushing movements such as benching for their upper body, and quad-dominant exercises like squatting for their lower body, which can lead to muscle imbalances. To counteract this, I would fill the first upper-body workout of the week with pulling moves, and the first lower-body session with hip-dominant moves (see below).

Stick to this plan and your lifting will improve, you’ll be more athletic on the sports pitch and more effective at day-to-day activities such as sprinting to catch a bus.

The Workout

Use King’s explosive workouts to build fast-twitch muscle and correct muscle imbalances. Do ten sets in each workout, starting with six to eight reps of each move. Rest five minutes between sets.



Hinge forward at the hips and pull the bar up to your lower sternum, using an overhand grip.


Grasp the bar underhand. B brace your core and pull yourself up until your chin is above the bar.


Curl the bar up to your chest, keeping your core braced and using an underhand grip.



Lift the bar explosively to chest height, drop into a half squat to catch it on your chest, then stand.


With an overhand grip on the bar, drive through your heels and contract your glutes as you stand.


With knees slightly bent and back straight, lower until you feel a moderate stretch in your hams.

Coach Staff

Coach is a health and fitness title. This byline is used for posting sponsored content, book extracts and the like. It is also used as a placeholder for articles published a long time ago when the original author is unclear. You can find out more about this publication and find the contact details of the editorial team on the About Us page.