Myofibril muscle fiber versus sarcoplasmic muscle fiber sounds like a pretty heavy topic. After all, you’re not after a science degree here. You just want to know what to do to build the fittest, best body in the shortest amount of time. Well, that is exactly why you need to know about these different muscle types and to train them differently for maximum results.
And, that’s why we present here the average person’s guide to functional muscle versus regular muscle. We also have some great examples of functional strength training workouts at the end of this post that you can incorporate into your own plan.
Why You Need to Know
We all have different goals for working out. The person who is primarily interested in strength and power is going to focus on a different muscle fiber based routine than the person who is primarily working to achieve aesthetics and muscle size. And what about the person who wants to be both strong and aesthetic? Should he be switching between the two?
Sarcoplasmic hypertrophy takes place when you want a muscle to get larger, rounder and fuller without specifically getting stronger or building new muscle cells.
Within each cell are located muscle fibers. In order to activate the muscle cells, you need to supply the cell with glycogen and energy via ATP. Also in the cell is stored fluid, called cytoplasm, along with organelles. The last component of the cell is glycogen.
When you are training for sarcoplasmic hypertrophy, the goal is to increase the number of organelles, cytoplasm and glycogen storage within the cell without increasing the muscle fibers. Over time, with repeat training, their will be some muscle fiber increase, but that it not the main goal here.
To train primarily for a sarcoplasmic response, you need to do high rep sets. The effect of that is to consume all of the glycogen in the cell. The body’s response to this is to tell itself . . .
Hey, I ran out of glycogen before the task was completed. The next time I’d better store some more glycogen.
That is exactly what will happen. As you train repeatedly with high reps, your body is going to store more and more glycogen within the cell. It will also create more organelles and store more cytoplasm. Over time, this will actually cause the muscle to increase in size, or hypertrophy.
Remember that the reason for the increase in the size of the muscle cell is because it is storing more glucose, creating more organelles and a higher content of cytoplasm. And the reason the body does these things is because it has determined that you are going to be doing a lot of repeated motions with a resistance and therefore need more energy. For that it needs more glucose.
More glucose then requires more organelles to break down the glucose and create energy. Cytoplasm is then needed to facilitate the creation of ATP energy. However, as already mentioned, the muscle fibers within the cell aren’t appreciably increasing in number. This will eventually occur, but it will be at a much slower pace than the person who trains with very few reps.
Myofibril hypertrophy has as it’s goal building lean, dense muscle tissue as opposed to increasing glycogen storage within the cell. The muscle fibers are located in the middle of the cell. Of course, you’ve still got cytoplasm, organelles and stored glucose within the cell also.
When you train at a lower rep range, as when powerlifting, you are not going to need as much glucose or organelles as when going with a higher rep range. For rep ranges of between one and three you don’t need as much energy as when you are doing ten, twelve or more repetitions. So, when you train in the lower rep range, your body will actually create more muscle fibers.
Again, over time there will be some spill over where you also increase the glucose storage, organelle numbers and cytoplasm quantity. This is because your body is having to accommodate to the increased number of muscle fibers within the cell. The more muscle fibers that are firing, the more energy you will need. However, this will be at a much slower rate than with sarcoplasmic hypertrophy.
With myofibril training, the cell doesn’t really get appreciably bigger in size. You will get a whole lot stronger, but your muscles will not get much bigger.
The Bottom Line
Sarcoplasmic training requires higher reps in order to burn glucose and stimulate a response that increases the storage of glycogen, organelles and cytoplasm with the cell. To achieve this response train in the 6 – 15 rep range.
You will have bigger muscles than a power lifter but you won’t be able to lift as much weight on singles because you lack the amount of actual muscle fibers to do so.
Myofibril training requires lower reps in the 1-3 range. It will make you stronger and will increase the number of muscle fibers deep within the cell but will not make your muscles bigger.
Can’t I Do Both?
So, why not have the best of both worlds. After all who doesn’t want to be both big AND strong, right?
You can be a jack-of-all-trades and train for both sarcoplasmic and myofibril hypertrophy at the same time, but the process is going to be a whole lot slower than if you were just focusing on one aspect of your training.
Of course, many of the great old time bodybuilders built a foundation for their careers with powerlifting training. Even though they probably had no idea about myofibril versus sarcoplasmic hypertrophy, they were, in fact, building the size and number of the muscle fibers with very heavy and very low rep training for a couple of years before switching focus to higher rep bodybuilding style training.
The result of this foundational power training is obvious when standing on stage alongside a guy who has never trained in the one to three rep range. The muscles of the myofibril trained athlete are denser, thicker and more rugged looking.
Another benefit of starting from a foundation of power training is that it will allow you to move up to using heavier weight more quickly when you switch to sarcoplasmic training. Remember that, even though you may be training with a higher rep range when training to increase the size of the muscle cell, you still want to lift as heavy as possible within the required rep range.
When you build up your power and strength base through myofibril training, you’ll be able to handle much heavier poundages more quickly, allowing you to build more muscle more quickly.
Power training also toughens and strengthens the tendons, meaning that you’ll be les likely to strain them when doing higher rep training with less weight.
And additional factor to consider is that muscle that is built upon a foundation of increased number of muscle fibers is easier to retain, even with a minimum of maintenance training. With high rep training, the increase in muscle size is a result of transient factors, such as glycogen levels, and fluid retention.
But cells that also have greater numbers of muscle fibers are much harder, meaning that they are less likely to shrink. Also, the muscle cell walls themselves actually grow thicker and tougher with myofibril training, again making them less likely to atrophy.
- Train with very low reps to get stronger (myofibril hypertrophy)
- Train with higher reps (6 – 15) to increase muscle size (sarcoplasmic hypertrophy)
- Doing both together will slow down both effects
- Focus on low rep training for the first couple of years then switch to higher reps once you have a foundation of power
Functional Strength Training Workouts
Myofibril Power Training
- Squats 4 x 8 /8 /6 /6
- Leg Press 3 x 12
- Deadlift 4 x 8 /8 /6 /6
- Bent Over Row 3 x 8/6/6
- Bench Press 4 x 8 /8 /6/ 6
- Military Press 3 x 8 /8 /6
- Barbell Curl 3 x 8 /8 /8
Sarcoplasmic Hypertrophy Training
- Lat Pull-down 3 x 12 / 10 / 10
- Seated Row 3 x 12 / 12/ 12
- Bulgarian Split Squat 2 x 12 (each leg)
- Lunges 2 x 12 (each leg)
- Goblet Squat 2 x 15
- Dumbbell Bench Press 3 x 12-15
- Dips 2 x as many as possible
- Pec Dec Flyes 2 x 12-15
- Cable Curls 3 x 10-15
- Overhead cable triceps Extension 3 x 12-15
You should train in the gym three times per week on this program, with a day’s rest between each session. The most common schedule is Monday, Wednesday & Friday, but you may prefer Tuesday, Thursday and Saturday.
Do your Myofibril Power Training twice per week on either Monday and Friday or Tuesday and Saturday. Focus on going as heavy as possible with proper form. On the middle day you should do your sarcoplasmic hypertrophy training. In this workout, your focus should be on exercising through a full range of motion, performing slow, constant reps and pumping the muscle with blood.