Workouts That Engage Fast-Twitch Muscles

Workouts That Engage Fast-Twitch Muscles

Have you ever noticed the contrast between the physiques of marathon runners and field stars? These striking differences are not just a matter of training regimens – they have roots in the very makeup of their muscles. You’ve probably heard of slow-twitch muscles and fast-twitch muscles, but what exactly are they and how can they affect the way you move and the way you look? Let’s explore fast- vs. slow-twitch muscle fibers, and then review ways you can cultivate your big and explosive fast-twitch muscles.


If you want to get nitpicky, the body is actually made up of muscles that fall into a variety of sub-categories. However, to simplify, it’s easier to divide muscles into two main groups: slow-twitch muscles and fast-twitch muscles.


Slow-twitch muscles possess their own mitochondria, which lets them use oxygen to create energy. This ability to power themselves up (using a chemical called adenosine triphosphate, or ATP) means that slow-twitch muscles are all about endurance. They can keep going and going.

Endurance athletes, like long-distance runners, swimmers, and cyclists rely on their slow-twitch muscles to help them make it from the start line all the way to the finish. You may also notice that these endurance athletes tend to be trim rather than heavily muscled. Slow-twitch muscles are not big or bulky.


Slow-twitch muscles have a low activation threshold. That means when you go out for a walk or jog, the first muscles your body recruits to get your legs moving and arms swinging are your slow-twitch muscles. It’s only when those muscles grow weary or they don’t have the power to generate a big, explosive movement that fast-twitch muscles enter the picture.

Fast-twitch muscles are all about force and power. If you want to jump, sprint, lift a heavy barbell, or tackle that linebacker, you’ll need some help from your fast-twitch muscles. These muscles are also primarily responsible for your body’s muscular definition and overall strength. As reports, “…if you’re looking to increase muscle mass and improve strength, using fast-twitch fibers is the only way to do it.”

Endurance work is great for improving your cardio, but sculpting comes down to fast-twitch training. That means focusing on movements that incorporate power and explosiveness. Remember, your body wants to use slow-twitch muscles if it can, so you need to add weight and intensity to your workouts to give your fast-twitch muscles a good workout.


Research indicates that your genes play a role in the amount of fast- vs slow-twitch muscle fibers you possess in your body. (You can’t turn slow-twitch muscle fibers into fast-twitch muscle fibers or vice versa.) Some of us are born with more slow-twitch muscle fibers while others enjoy a higher ratio of fast-twitch muscle fibers. That may explain why some people can jog five miles without breaking a sweat while others look like they have rockets strapped to their feet when they sprint down a straightaway.

Don’t let your genetic predisposition get you down. Unless you plan to be a professional football player or a cross-country skier, it doesn’t really matter whether your body favors fast-twitch or slow-twitch muscle fibers. You still have both kinds, and you can still train your fast-twitch muscles. If you fall on the slow-twitch muscle side, you may need to work a little harder for your results and you may never be as swoll as Arnold Schwarzenegger was in his day, but you’ll still see impressive results if you train the right way.


The name of the game is power, speed, and explosiveness when it comes to training your fast-twitch muscles. To engage your fast-twitch muscles, you’ll need to go big and hard in your workouts. Just remember to always warm up your muscles before putting them through big movements. If you plan to throw around big weights, make sure you feel comfortable with the movements and ideally have a workout buddy to spot you.

Here are some fast-twitch exercises you can do to engage those specific muscle fibers. 


Lifting light or moderate weights will not be enough to wake up your fast-twitch muscles. According to ACE Fitness, “Resistance training with heavy weights stimulates muscle motor units to activate more muscle fibers. The heavier the weight, the greater the number of fast-twitch fibers will be recruited.” Build up in weight and then, when it gets heavy, focus on short sets of only a few reps.

Muscle & Fitness suggests using 55-82.5% of your 1RM on your lifts and to “perform each rep as explosively as possible through the full range of motion.” (Your “1RM “or one rep max is the heaviest weight you can do for that movement). Keep in mind that your fast-twitch muscles deplete quickly. Make sure you add 60 to 90 seconds of rest between sets.

It is crucially important that you focus on maintaining good form when lifting heavy weight, or you risk injury. If you’re just starting your fitness journey, consider using resistance machines at your local gym. When you feel more comfortable with the movements, transition to dumbbells and barbells.


You don’t necessarily need weights to work your fast twitch muscles. You can activate your fast-twitch muscle fibers using only body movements as long as those movements are explosive. One of the easiest fast-twitch exercises to do is sprinting. Head over to the local high school or college track or find a flat stretch of sidewalk near your home (if your joints are healthy). Then put yourself through sprints.

This is all about power, so keep your sprints short and intense. You should try to maintain at least 80 percent of your fastest speed throughout the sprint.

On a track, consider sprinting the straight aways and walking the curves for four laps with a rest between each lap if necessary. If you’re not on a track, you can always use a stopwatch (or stopwatch app) to sprint for 20 seconds followed by 40 seconds of walking. Repeat that 10 times and you’ll get an excellent workout.


Another way to invite your fast-twitch muscles to the party is to perform a plyometric workout. Plyometrics is all about jumping. As long as you perform these jumps explosively (no slow and easy jumping jacks, unless that’s your warm-up), you’ll recruit your fast-twitch muscle fibers. Plyometrics also helps you engage a wide range of muscles, as well as improve your coordination and body awareness. Just make sure your joints are in good shape. Plyometrics can put a strain on ankles, knees, and hips.

A simple plyometric workout could include three sets of five box jumps, five broad jumps, and single-leg cone jumps (five on each leg). You may also want to see if your gym offers a plyometrics class.


Combining power, explosiveness, and heavy weight, Olympic lifting is the fast-twitch muscle trifecta. It’s also an advanced form of fitness that requires guidance and practice, especially as you learn the movements. Olympic lifting is comprised of two primary movements: the clean and jerk, and the snatch. Both movements require you to lift a heavy barbell overhead. The snatch movement entails getting the bar from the ground to overhead in a single movement. The clean and jerk includes moving the bar to the chest (front rack) and then jerking it overhead.

Again, these movements are complex. You should not attempt them without instruction and guidance from an experienced Personal Trainer.

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fast-twitch muscles faqs

What are fast-twitch muscles?

Known as Type II muscles, fast-twitch muscle fibers are a category of skeletal muscle fibers in your body. Muscles consist of fibers, and the brain stimulates those fibers through electric impulses to make them contract. Type II muscles are further broken down into two sub-categories: Type IIA and Type IIB or Type IIX. Type IIA can recover more quickly than Type IIB; but Type IIB provides the fastest, most powerful muscle contractions compared to the other types. However, they’re also the least efficient since they tire the fastest. 

Why do athletes need fast-twitch muscles? 

Fast-twitch muscle fibers contract quickly, tire rapidly, and help you perform fast, high-intensity activities for short periods of time. For athletes, fast-twitch muscles help with sprinting, box jumping, weight lifting, strength-training, and activities that require substantial strength or power. 

What are the benefits of fast-twitch muscles?

Fast-twitch muscles are about strength and power, and they also happen to store a high amount of carbohydrates. You’ll draw 3g of water into the muscle for every gram of carbohydrate you store, helping your muscles to obtain a fuller, denser look. Fast-twitch muscles are designed to help you during short, intense activities including:

  • Sprinting
  • Agility training
  • HIIT
  • Powerlifting
  • Strength training
  • Jumping
  • And High-intensity cycling

Can training my fast-twitch muscles help me build mass?

When it comes to building muscle mass, the only way to do it is to engage your fast-twitch muscles as they have an impact on your body’s muscular definition. You want to focus on movements that incorporate explosiveness and power to build more muscle mass. 

What are some fast-twitch muscle exercises for weight loss?

To lose weight and engage your fast-twitch muscle fibers, try interval or sprint training. 

How do you train your fast-twitch muscles? 

When you want to train your fast-twitch muscles, make sure to focus on high-intensity, low-duration exercises, such as box jumps, jump squats, stair climbing, and kettlebell exercises. Keep reading below for an in-depth look at some fast-twitch exercises


If you’re keeping your workouts light or moderate, you might be missing out on activating your fast-twitch muscles. If you dream of well-defined muscles or want to lose weight (more muscles burn more calories throughout the day), it’s time to get your fast-twitch muscles into the game by adding power, speed, and explosiveness into your workouts.

Ready to take your fitness game to the next level? At EōS, we’re wildly passionate about helping you unleash the power of both your slow-twitch and fast-twitch muscles. Our EōS Yard® offers a top-notch turf area for functional training, and our Group Fitness Classes deliver the motivating energy you’re looking for. Not a Member yet? Don’t sweat it! Grab a Complimentary 7-Day Pass or find an EōS Fitness near you.

Workouts that engage fast-twitch muscles. Two kinds of muscle fibers- there are two primary types of muscle fibers that aid in movement. Fas twitch muscle fibers and low twitch muscle fibers. Fast twitch muscles are muscles are recruited for powerful, explosive movements like jumping and sprinting. Slow twitch muscles are used for endurance activities like jogging, moderate paced biking and walking. What fuels fast twitch muscle fibers? Fast twitch muscle fibers are anaerobic, meaning they don't use oxygen. Instead they are fueled by the energy already stored in your muscles in the form of ATP (adenosine triposphate). Did you know? Most people are born with a roughly even amount of slow twitch and fast twitch muscle fibers? However, a few people are either slow twitch of fast twitch dominate. Most champion weightlifters are fast twitch dominate, while elite marathon runners tend to be slow twitch dominate. Why train your fast twitch muscles? Fast twitch muscles are primarily responsible for your overall strength and your body's muscular definition. Fast twitch muscle training can help you: Get stronger, jump higher, train faster, become more powerful, build a more define physique . How to train your fast twitch muscles? It's all about power, explosiveness, and speed. To engage your fast twitch muscles, you'll need to go big and go hard in your workouts. Best practices: Always remember to warm up before your workout, especially if you plan on putting your body through big movements. Lift Heavy weights. Work your way up to 55% to 82% of your 1RM (one rep max weight) and perform each rep as explosively as possible. The more weight you lift, the more fast twitch fibers you recruit. Perform short sets with a small number of reps. Best practices: focus on maintaining good form when lifting heavy weight to lower your risk of injury. If you aren't comfortable with free weights use resistance machines instead. Sprint- who needs weights? Grab a track or a sidewalk and take off. Keep your sprints short and intense. Try to maintain at least 8-% of your fastest speed throughout the sprint and allow yourself plenty of rest between sets. Jump. Plyometrics, or jump training, can help strengthen your fast twitch muscles as wells as improve your coordination and body awareness. Focus on explosivity. Exercise options include: squat jumps, jumping to a plyo box or riser, broad jumps, single leg jumps over a cone. Best practices: If you have knee, ankle, back, or hip pain, avoid intense jumping exercises. HIIT Workouts- High intensity interval training puts you through intense bouts of anaerobic movements followed by short periods of rest. Try to hit between 80% to 90% in each round to get the most bang for your buck. Olympic lifts. There are only two Olympic lifts: the snatch and the clean & jerk- but there are nearly endless derivatives of both movements. Each lift combines power, explosiveness, and heavy weight- the fast twitch trifecta. Best practices: Olympic lifts are advanced movements. Do not attempt without proper instruction or guidance. Need help? Not sure how to get started with fast twitch training? Consider working with a personal trainer who specialized in strength training.

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