Fast Twitch Muscle Fibers Training 101


muscle fibers

If you’ve never heard of fast twitch muscle fibers you’re not paying close enough attention. Here’s everything you need to know about the coolest thing your body does to make you stronger in the gym on a daily basis.

You have surpassed the basic fundamentals and now need more to your workout. The time has come to join the ranks of the more advanced weightlifters and bodybuilders.

This is not implying you have to be a giant. No, you don’t need that. But, if you want to add more muscle mass, then you will have to eventually change your training program.

What type of change do you need to make?

It needs to be more specific. Specialized training is great for boosting size on specific muscle regions. But, fast twitch muscle fiber training is like accomplishing specialized training for all of your muscles. Let’s take a deeper look into this training program

What Are Fast Twitch Muscle Fibers?

Fast twitch muscle fibers are the largest muscle fibers in your body. They produce the sheer strength and power to burst into an exercise for a short period of time. They hold the most carbs to use as an immediate energy source, and they are what give you a larger, more muscular appearance.

The reason for this is because fast twitch muscle fibers also hold the most water weight. Of course, carbs are water soluble.

Most people think of this as a bad thing. It really isn’t.


If you want bigger muscles, you need carbs and water to support those large muscle fibers.

Genetics Are Slightly The Issue

Genetics are what you were born with. We can’t change what genes our parents have granted us, and some people simply have more specific muscle fibers than others. Often we see a guy who can lift pretty decent loads of weight, but he has a small body frame. The reason for this is because he has an abundance of slow twitch muscle fibers. His genetics were intended to make him a great runner.

But, just because your genes are not what you wanted that does not mean you can’t change your body type naturally. All your genetics mean is how much harder you may have to work before you are able to build those larger muscles. But how much larger also depends on what your body is capable of developing. The two variables that assist with targeting fast twitch muscle fibers are load and fatigue.

How Do Muscle Fibers Help Overcome Growth Plateaus

Growth plateaus occur when your body is no longer responding to the training and diet program you are currently on. People who are doing everything possible often just seem to be stuck against a wall.

This is where muscle fiber training comes in regardless if it is for the slow twitch or fast twitch fibers. When you target these more specifically, then you have a good chance to push through your muscle building or fat loss plateaus. Start with your regular training and diet. If you find that the changes you make do not work, then you can carry on to muscle fiber training.

Nutrition Is Vital!

A poor diet essentially kills the possibility of fast twitch muscle fiber recruitment. You have to be consuming enough calories to support muscle growth, provide energy for training and to keep your overall body functions healthy.

A calorie deficit-focused diet is meaningless for fast twitch muscle fibers. So eat plenty of macros to gain the muscle mass you want and to keep your body from feeling fatigued due to poor recovery.

muscle fibers training

This Is How To Activate Fast Twitch Muscle Fibers

Are you ready?

Good. In that case, let’s get to the good stuff now. Activating muscle fibers means you have to do movements that significantly increase your max potential. For endurance, this would mean you have to be doing sprints. For weight training this would mean heavy lifts with 80% or more being used for the load setting.

But we do not just use heavy loads.

Research showed that powerlifters and Olympic weightlifters use their fast twitch muscle fibers more effectively with heavy loads and low volumes. Bodybuilders had less activity in these muscle fibers because they focus on doing 8 to 12 reps with moderate loads, but then their rest time is around three to five minutes just like powerlifters.

Why are bodybuilders much larger?

The reason why is because the moderate training style has increased their slow twitch muscle fibers. So you see much larger muscle mass because two different muscle fibers are being used. You are targeting fast twitch fibers because you want more power, strength and force output to do larger lifts while also increasing muscle size.

Fatigue Is An Important Factor

The intensity from your load is just one way to target fast twitch muscle fibers. The other one would be muscle fatigue. Your body wants to first increase slow twitch muscle fibers, which again is why bodybuilders have more mass than powerlifters. However, once you manage to fatigue those muscle fibers, a new one needs to be activated to take its place.

Research shows that fast twitch muscle fibers will be recruited to be the replacement for the responses that were intended for slow fibers. Within this study was another particular incident that shows fatigue is necessary for fast twitch muscle fibers to be recruited.

A group of athletes had to do four sets of eight reps each. They were doing intense exercises to force intra-set rest to take place. Intra-set rest is not done on purpose and is when you pause for a quick moment before your next rep. The study showed that those who took an intra-set rest lost gains to their fast twitch muscle fibers, regardless of how long the break lasted.

This study shows us that we want fatigue to occur and need to allow it to happen. What does this mean to you? You need to decrease the amount of rest you take between each set to reach maximum benefits for recruiting fast twitch fibers.

These Are Steps to Take for Increasing Fast Twitch Muscle Fibers

As we discussed, the use of heavy loads and intentional muscle fatigue are the two main ways to activate these muscle fibers. But how do you go about accomplishing this task?

First, every two to three training days, you should have a heavy set training day. These heavy days should focus on multi-muscle/joint movement for better use of your fast twitch muscle fibers. Plus they are proven to increase natural free testosterone release. What are some good exercises to do? Some of the ones you could try include deadlifts, squats, bench press, pull-ups and the overhead press.

Then, the other training days allow you to decrease load and increase volume. Do not take any type of rest during a set, regardless of how tired your muscles feel. Push through the pain if you can safely keep going. This is what spotters are good for. Do not worry! Muscle pain is only temporary and will subside eventually.

What about isolation lifts? Isolation lifts are actually used on the lighter training load days with very short breaks between sets. Usually with lighter loads you will want to superset them with an exercise that matches them.

Of course, to superset means to simply do an exercise that immediately follows the set of the other. For example, if a program wants you to superset by doing the biceps curl exercise for four sets of 12 reps first and then the triceps extension exercise for another four sets of 12 reps, then what you do is simple. First, you would perform one set of biceps curl exercise. Then, right after that, you do one set of triceps extensions. This will count as a full superset. You should then take a 30 to 60-second break.

This Is Your Fast Twitch Muscle Fiber Recruitment Workout

Most of the exercises used for this workout are compound lifts. Of course, you may have heard of them being called “big lifts” as well. These are the most beneficial for you to achieve fast twitch muscle fiber recruitment. But there will be some isolation exercises thrown in as well.

You only need three training days for this workout program. They will be full-body workouts that require at least 24 hours of rest before the next training day. The two rest days are intended for you to actually rest and consume nutrients to boost your recovery process and recruitment of these fibers.

muscle fibers training 101

Let’s Take A Look At How Your Workout Days Are Going To Be…

Heavy set training days are always first so you have all the energy from the back-to-back rest days.

Day 1 Workout: You should do heavy compound lifts only.


Day 2 Workout: You should do moderate compound lifts only.


Day 3 Workout: You should do a light mix of compound and isolation lifts.




Day 1 Workout: 5 sets with 1 to 5 reps.

Day 2 Workout: 4 sets with 8 to 12 reps.

Day 3 Workout: 3 sets with more than 12 reps.


Use this training program for six to eight weeks for best results in recruiting fast twitch muscle fibers.


Day 1 Workout (Heavy) The rest between sets should be three to five minutes.

Exercise Sets Reps

Barbell Squats 5 5,4,3,2,1

Barbell Bench Press 5 5,4,3,2,1

Normal Deadlifts 5 5,4,3,2,1

Barbell Lunges 5 5,4,3,2,1

Seated Dumbbell Overhead Press 5 5,4,3,2,1

Rest Day


Day 2 Workout (Medium) The rest between sets should be 60 to 90 seconds.

Exercise Sets Reps

Sumo Deadlifts 4 8-12

Incline Barbell Bench Press 4 8-12

Bent Over Rows (not Yates Rows!) 4 8-12

Barbell Front Squats 4 8-12

Standing Barbell Overhead Press 4 8-12

Rest Day


Day 3 Workout (Light) The rest between sets should be 60 to 90 seconds.

Exercise Sets Reps

Squats 3 12-15


1st – Reverse Wide-Grip Bench Press 3 12-15

2nd – Flat Bench Reverse Fly 3 12-15


1st – Lat Pull Downs 3 12-15

2nd – Wide-Grip Upright Rows 3 12-15


1st – Leg Press 3 12-15

2nd – Leg Curls 3 12-15


1st – Barbell Curls 3 12-15

2nd – Seated Overhead Triceps Extensions 3 12-15

Rest Day

Rest Day

You Should Be Stretching Before And After

We recommend you do a 5-minute warm-up stretch routine prior to training and following training. Before training you help joints stretch to their full range of motion to prevent injuries.

After training you do this to keep your muscles from stiffening up and having muscle spasms. You may need to do some stretching before bed as well if your muscles are too sore. Stretching actually decreases muscle recovery time. But, that is not to be confused with delayed onset muscle soreness.

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Get ready! These types of workouts are not easy. But, that should not bother you. Why? No good workout really should be easy. If you are ready to start recruiting faster twitch muscle fibers, then this workout program is a great starting point

After two months, you should switch to a regular training schedule of four or five training days a week for a minimum of four weeks. You can then resume fast twitch fiber training with another hard two months of training.


– By Brian Pankau, CPT




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