8 Weeks of Strength Endurance for Muscle Growth

By Alexander VanHouten, Master Trainer & Life Time Education Specialist

How do you grow muscle tissue? The stereotypical response is usually something like “lift all the weights!”

Everyone knows that lifting weights has something to do with an increase in lean body mass. And if you’re really good with your workouts, you know that there are certain acute variables you can change in order to create certain adaptations.

You wanna grow muscle? Lift heavier with less reps. Right?

Well, not exactly.

What if I told you that part of your muscle plateau has to do with not training enough endurance?

I can hear your incredulity: “What do you mean ‘train endurance’? Doesn’t endurance training reduce muscle tissue?”

And I would have to concede the point that there are very few marathon runners with muscle coming out of their ears.

But I’m still right. And my argument remains intact because there is a difference between cardiovascular endurance and strength endurance! And strength endurance could be what your muscles are missing to take your muscle mass, and your metabolism, to the next level.

What is Strength Endurance Training?

Strength endurance, unlike cardiovascular endurance, refers to a foundational training phase in resistance training program design. This phase of training refers to a modulation in weight, reps, sets and rest periods, so that you are lifting lower weight for higher reps with less rest. Sounds easy, right? It’s not. And if it’s done right, strength endurance training results in increased mitochondrial density, capillary growth, and type 1 muscle fiber development.

What does that have to do with growing muscle? Let’s explore…

Mitochondrial Density Increases Energy Production and Output

I need you to dig back into high school biology for a bit. Mitochondria are the powerhouse of the cell. Remember that soundbyte? They produce ATP from pyruvate (carbs/fat after your body breaks them down) and your cells use that ATP to perform important functions. Mitochondrial density refers to the amount of ATP-producing power-houses in each muscle cell.

Ok, so mitochondria are important for energy production. But, what does that have to do with growing muscle?

More mitochondria = more energy produced in muscles. More energy produced = more energy available to use in muscles. More energy available = more force production potential in the muscles. More force produced in a workout = more muscle growth stimulated. Therefore more mitochondria = more muscle growth. QED.

In other words, when you train strength endurance, you increase your muscle’s powerhouses to produce and output more energy. And that leads to more muscle growth when you get back to lifting heavy.

Score one for strength endurance.

Capillary growth creates a network to bring fuel to muscles you want to be larger

Capillaries are the tiniest blood carriers in your body. Only visible in the whites of your eyes, capillaries are the points in your circulatory system where the walls are so narrow that red blood cells line up single-file to give life-giving, energy-producing, muscle-growing oxygen and nutrients to the surround tissues. They are very important places in the body.

Something else is special about capillaries: Your body can grow more of them.

You think mitochondria are important? Imagine how much more important the fuel supply for those mitochondria are.

If you want larger muscles, you need more capillaries and the best type of training to grow them is strength endurance.

That’s 2.

Type 1 Fibers Stabilize Type 2s

The significance of and different kinds of muscle fiber types in reaching your desired fitness goals cannot be overstated.

Though the differentiation and ramifications of muscle fibers deserves it’s own book, I am going to attempt a very high-level summary of the topic so that you understand what endurance training has to do with growing muscle tissue.

Here it goes: Type 1 fibers are smaller, more endurable fibers that take a long time to crap out. Type 2 fibers are bigger, stronger fibers that tire quickly. A person with a lot of type 1 fiber development looks long, lean and can generally perform well during tasks of endurance (think triathlete or yogi). A person with a lot of type 2 fiber development generally appears toned and performs well during feats of strength, speed, or power (think sprinter or gymnast).

When a person trains to “grow muscle” they generally exercise in a way that improves type 2 development.

Awesome. Makes sense.

However, what’s missed is that Type 1 fibers in the body lend endurable stability to strength movements.

For instance, if I want to grow my chest muscles, I should do hypertrophy training. That is, 8-12 repetitions of bench press for 3-6 sets with 90 seconds of rest in between. However, the amount of weight that I can lift for that number of reps is significantly reduced if my type 1 fibers in my rotator cuff, serratus, lower trapezius and lats (all muscles that lend stability to the bench press) are underdeveloped.

In other words, the underdevelopment of type 1 stabilizers limits the intensity that I can work to train my type 2’s without injury. Therefore, one can easily say that strength endurance is the foundation of an effective muscle-growing program.

So by increasing mitochondria, growing capillaries, and supporting type 2 performance with type 1 stability, strength endurance creates the necessary machinery to grow new muscle tissue.

Awesome, I’m sold, Alex. But how do you execute?

Get on the Endurance Train

In general, strength endurance is best developed in the beginning of one’s fitness program. I usually recommend my most conditioned clients visit a strength-endurance regimen at least twice/year.

Weeks 1 and 2: Prime the body

Acute Variables: Sets – 2; Reps — 15-20;  Tempo 2/0/2; Rest 30s; Supersets – No; Total Time 30-40 minutes

4 Days: Upper Body Push; Lower Body; Upper Body Pull; Total Body

These two weeks are about priming the changes I highlighted here. Use the heaviest weight you can to complete the reps listed with good form. You’ll feel the burn, but won’t be too sore afterwards.

Weeks 3 through 6: Turn up the heat

Acute Variables: Sets – 2; Reps – 15-20; Tempo 2/0/2; Rest 30s; Supersets – Yes; Total Time 40-50 minutes

4 Days: Upper Body Push-Pull; Lower Body Squat-Lunge; Total Body (circuits); Lower Body Bend-Lunge

These weeks introduce supersets and circuits. They will allow you to do nearly double the work of the previous 3 weeks in less time since you are working other muscle groups during your 30s rest periods. Expect to get out of breath and sweaty during these weeks and find yourself more sore after workouts. Recover Hard.

Weeks 7 and 8: Feel the burn

Acute Variables: Sets – 3; Reps – 12-15; Tempo 2/0/2; Rest 30s; Supersets – Always; Total Time 40-50 minutes

4 Days: Upper Body Push; Lower Body Squat-Lunge; Upper Body Pull; Lower Body Bend-Lunge

These weeks put the icing on the cake with an increase in volume and weight, and a decrease in reps. The struggle of knocking out the last set of 12-15 on each exercise superset will find you feeling the growth of capillaries, stimulate type 1 failure and boost those mitochondria. A good pre-workout can help this period not feel so rough. Prepare to be sore!

Now What?

After 8 weeks of true strength endurance training, its time to grow in hypertrophy. Once you get to this phase with such a foundation for growth, you’ll be surprised at the results you’ll see after just your first 2 weeks!

I’ll see you on the fitness floor. Laying the groundwork for your muscle has never felt so good.

The posts on this blog are not intended to suggest or recommend the diagnosis, treatment, cure, or prevention of any disease, nor to substitute for medical treatment, nor to be an alternative to medical advice. The use of the suggestions and recommendations on this blog post is at the choice and risk of the reader.