Add more muscles by understanding the training variables and how they affect your muscle hypertrophy.

Let me tell you my story

I had joined a gym to build BIG BIGGER muscles. The gym did not provide any trainer. I know nothing about workout programs, I start lifting weights.

After few weeks my strength increased as I lift weights. My muscle size increased with month after month.

The muscle growth diminished after that and I was worried about that.

Later I met a bodybuilder and I told him about my workouts. It did not take him too much time to spot the fault in my workout.

Latter I understand that he had altered three training variables in my workout that changed my muscle building journey.

In this article you can learn about

· Training variables and their effect on hypertrophy

· How to optimize your training for muscle growth

· How to stay in a hypertrophy mode

Training Variables

Workout programs are designed by considering these training variables. By understanding these training variables you can optimize your workout routine for muscle growth.


first training varible workout intensity

Intensity is the level of energy spends during exercise as Wikipedia says it.

In weight training the intensity refers to the weight lifted. It is the amount of effort produced compared to effort possible. 

Intensity is expressed as a percentage of 1RM by counting the number of reps done with a particular weight.

1rep max FIGURE

Workout intensity of 80- 95% 1RM has shown maximal hypertrophy gains.

It’s proven that you should increase your workout intensity for muscle building.

intensity weight loading

But keep in mind that you have to be aware of overtraining. Don’t over train in a hope to increase intensity and muscle growth.

The remaining training variables directly influence your training intensity; we can’t isolate intensity from the rest of training variables.

Our take: Your muscles need stimulus to grow, so you have to increase the load week by week. This doesn’t mean that you have to add 10 or 20KG every week. A small increment of 1kg or 2kg is better than lifting constant load.


second training variable workout volume

Volume is product of number of reps, sets and weight lifted in a workout session; it is the amount of work done.

Volume= Reps *Sets *weight

Higher volume workout has been shown to increase hypertrophy. The research has shown some interesting things.

Beginners will the most benefit from low volume workouts. If you are a beginner try a low volume workout.

But as you progress you will need high volume (multiple sets) to stimulate workout induced hypertrophy.

High volume workout session has been shown to increase testosterone and growth hormone levels in humans.

In another study higher volume (multiple sets) results in 40% increase than low volume group. Both beginners and advanced lifters experienced same hypertrophy benefits from multiple sets of exercise.

volume load

You have to progressively increase your training volume to attain muscle growth over a period of time.

You can do this by either increasing the weight lifted, reps done, or sets completed in any exercise.

But be aware of overtraining, as higher volume can lead to overtraining.

Overtraining will have negative effect on your performance and can stop your muscle growth.

Overtraining can reduce your growth hormone and testosterone levels. The catabolic hormone cortisol will increase on overtraining.

Small percent of cortisol due to training will have growth promoting effects, as it will signal your body to repair and aids in GH release. Elevated levels of cortisol will promote muscle breakdown in your body.

To prevent overtraining you have to give enough recovery time (training frequency) in your workout routine.

By now you will be thinking about how to increase your training volume without over training. We will see it later in this article.

Our Take: Increase in workout volume promotes hypertrophy. But increasing workout load and volume can cause overtraining, so it will be safe to reduce the volume while you increase intensity.


third training varible workout frequency

Workout frequency is the number of resistance training sessions in a week.

For beginners or untrained lower frequency training is superior to higher frequency training.

For experienced or advanced lifters higher frequency training is good for hypertrophy.

Training four times a week is optimal for hypertrophy gains. This will enable you to train specifically for each muscle group and will aid in recovery.

High volume high frequency training will add up your training intensity. Higher intensity will tax your muscles as well as your nervous system.

By limiting the frequency to 4 days per week will make sure that your body will recover from damage.

We have talked about frequency related to workout sessions per week,

There is one more thing that is also note worthy. It is muscle group training frequency.


It’s the number of times a muscle group has been trained in a week, i.e. a muscle group will be trained 2 or 3 times a week.

Your muscle will recover within 36 hours after training session. Workout routines are created which target each muscle group twice or thrice a week.

In long run this workout routine can cause overtraining.


Your muscle recovery depends on other factors like workout volume, intensity, etc.

If you hit your muscles multiple times a week and with high intensity and volume for long term you are inviting injury and overtraining.

Now you know the three training variables that I had told in the beginning of article.

Our take: For beginners 2 or 3 days per week will be good for muscle growth. But as you advance and become experienced 4-5 days per week works best for muscle building.

Muscular failure

fourth training varible workout muscle failure

Muscular failure is a point in which you are not able to do one more rep without the help of a spotter.

It adds the intensity of your workout.

Training till muscular failure will maximize your muscle hypertrophy. You can include this type of training periodically to shock your muscles and motor neurons.

This helps to add more strength and hypertrophy in advanced lifters.

How this happen?

While training your motor neurons of smaller threshold will be working to enable muscle movements.

Training till failure will fatigue them causing the higher threshold (or greater number) motor neurons are recruited do the work. This will helps in greater activation of motor neurons.

Muscular failure will helps to increase metabolic stress. As you read in first part of muscle growth, metabolic stress will increase your hypertrophy.

Training till failure caused elevated levels of Growth hormones after exercise when compared with non failure training.

Will muscular failure cause overtraining?

Yes, if you include this in all training session.

Research has proved that you can include muscular failure in your workout routine safely. Add them once or twice a month in your workout routine.


You have to lift sufficient weight to enable muscle hypertrophy. Don’t think that a weight 10% 1RM done till muscle failure will get the desired hypertrophy gain.

By doing so you will get the pump, but it will not bring any strength gain or muscle growth.

Our Take: To increase intensity and metabolic stress, don’t finish your reps till failure on one or two exercise. Don’t overdo as it can cause fatigue to muscle and nervous system.

Muscle action –eccentric over concentric

eccentric muscle action

Eccentric muscle actions have hypertrophy benefits over concentric muscle actions. We have discussed about eccentric muscle actions in previous post about muscle growth.

This study found that your muscle hypertrophy gains will not be efficient unless you focus on eccentric muscle actions .[study]

“Increases in muscle hypertrophy are slightly greater with Ecc compared with Con training, and neural adaptations are similar but are dependent on training and test mode”

Another study on fast training found out that eccentric training produce greater hypertrophy than concentric training.

“During eccentric portion passive muscular tension develops in your muscles. This happens due to the stretching of collagen content and other elements in your muscle fibers. This will further increase the tension on the myofibril (smallest unit of muscle fibers), thus multiplying the hypertrophy benefits.

How to apply?

Eccentric focused workout can be applied on the last set of any workout.

If you do 6 reps in your last set, try to do 4 forced reps with the help of a spotter.

While lowering weight try to lower the weight yourself in a controlled manner without spotter.

This will cause passive muscle tension and multiply your muscle growth.

Our Take: eccentric loading helps to build up passive tension in muscle. Add them to your finishing set; use a spotter to help you lift the weight. Then lower the weight in a controlled manner.

Repetition speed / tempo

fifth training variable rep speed

It’s the speed at which the bar is raised or lowered during workout. Repetition speed has an effect on your hypertrophy.

The study conducted on repetition speed of concentric muscle action shows that higher rep speed is beneficial for muscle growth. This study shows that a 1s concentric rep speed is better than 3s for hypertrophy gains.

“Take more time while you lower the weight, this increases passive muscle tension and benefits your training response.”

Moderate speed repetition workouts will provide hypertrophy gain, due to an increase in Time Under Tension (TUT).

“The time under tension is the total time that a working muscle is under strain during a set.”

Research shows that slow reps’ training is not optimal if your goal is muscle growth.


I am confused while writing about rep speed; fast reps and moderate reps are both beneficial to hypertrophy.

In fast reps training more motor units will be activated thus enabling hypertrophy.

In moderate speed the key factors is time under tension.

You can reap the benefits of two techniques.


Add fast reps in your first workout and use other in second workout. You can cycle them in between your workouts.

Add fast reps technique in your first 2-3 sets as you will be lifting lighter than finishing set. Thus more force will be produced by your muscle.

  • Force= mass X velocity

This will help in your finishing set to lift more weight.

Fast reps are fine; but no cheating is allowed here. You have to pause at the bottom before next rep, thus preventing cheating.


It is the speed (count) at which each muscle action is completed during workout; this is the pattern for representing tempo.

Eccentric ( lower the weights)count - pause in between ecc and con action ( pause at bottom) count -concentric action( lift) count - pause between con ecc action( pause at top)count


3 count for eccentric contraction- pause at bottom -1 count for concentric contraction​- Pause at top and repeat.

Our Take: while you exercise do the concentric portion faster. Then slowly (3s) return the bar to starting position.

Exercise selection

sixth training variable exercise selection

Your muscles are complex unit of different type of fibers with different characteristics. They vary in arrangement, strength, level of endurance etc.

This demands variety workouts that can stimulate the muscle fibers for maximum hypertrophy.


You need to add multi joint and single joint exercise in your routine.

Multipoint or compound movements will hit large muscle groups. Which elevates your anabolic hormone levels (GH and Testosterone).

Compound movements use stabilizer muscles during workout.

Single joint exercise target one or two muscles, this is beneficial to for stimulating lagging muscles. This also helps in maximizing the growth of entire muscle mass.

Let us see the importance of exercise selection.

This research has been conducted on squat performance on unstable platform. It show a 40% reduction in force produced when compared with stable platform.

See this study,

Muscle activity of core muscles were observed on stable and unstable surface. The result shows that maximum muscle activity was on unstable platform.

So there is a need to understand the exercise and their impact on muscles. You have to choose the exercise that helps you reach your goal.

Our Take: Choose compound workouts for your hypertrophy goals as they use more muscle groups. Use isolation exercise to target lagging muscles.

Rest interval

training variable rest interval

Rest interval is the time taken in between sets in a workout.

Your muscle cell similar to others uses ATP as their energy source. ATP after releasing energy will get converted to ADP.

ADP is then converted to ATP by enzymes and this is a cyclic process.

Your muscle will use the available ATP during lifting, thus your ATP stores will get depleted. So you have to get rest in between sets for the recycling of ADP to ATP.

Shorter rest periods(less than 30s) are shown to increase metabolic stress on muscle, that will kick start your anabolic process. But this will affect your performance in subsequent sets.(not enough time for ADP to ATP recycling)

Longer rest intervals (120-180s) often used by power lifters, will enable them to lift with full strength. (Ample time for ADP to ATP recycling). This type of training reduces your metabolic stress which affects hypertrophy responses.

Medium rest interval (60-90s) is best suited for hypertrophy. Major share of your strength will be regained with in 60s (ADP to ATP recycle).

This ensures that your lifting performance will not be affected.

There is one more benefit:

Medium rest intervals cause the buildup of metabolites in muscle, resulting in metabolic stress.

Our Take: 60- 90s rest interval for maximum hypertrophy. Take more time if you want to break your Personal record 🙂

Workout Tuner Card

You have read about 8 workout variables and their impact on muscle growth. You have to apply these in your workout to be on a hypertrophy mode.

workout tuner card

Intensity and volume: you have to increase load workout after workout( you have done 10 reps in past week, now you can add more weights and do 6 reps) and the following week try to do 8 and then 10 reps.

Workout frequency: 4 days per week

Muscular failure and eccentric Loading: For eccentric loading you can use forced reps with the help of a spotter. On alternate weeks replace this with muscular failure, that needs you don't finish your reps till failure. You stimulate muscle growth by muscle tension and metabolic stress.

Rep speed: lift( concentric ) the weight faster and lower(eccentric) the weight slower [ Rep tempo -  3-0-1-0 ]

Rest interval: 60- 90s rest interval for maximum hypertrophy. Take more time when you want to break your Personal record

Exercise selection:  Choose compound workouts for your hypertrophy goals as they use more muscle groups. Use isolation exercise to target underdeveloped muscle.

You have to be careful when altering the above variables. Volume, intensity and frequency are important training variables.

Increasing your volume, intensity and frequency can seriously affect your recovery and can lead to overtraining.

As Paul carter call this “the sliding scale of frequency/volume/intensity to meet the recovery variable”.

If you increase one you have to decrease one or two variables considering your recovery.

workout frequency - 4 days/week

1st week you have done 50KG bench press with 10 reps – volume for this set- 50*10*1=500

2nd week you increase and try 55KG with 6 reps- volume for this set- 55*6*1=330

3rd week you increase reps try 55KG with 8 reps- volume for this set- 55*8*1=440

4th week you increase reps and try 55KG with 10 reps- volume for this set- 55*10*1=550

This enables to cycle the volume thus preventing overtraining.

Every four week you hit higher volume and lift more loads.

Wrapping it up

You have learn about training variables and know how to tune them for maximum muscle gain.

You have to keep an eye on overtraining symptoms, and tune your workout to get desired results.

What's your thought on workout tuning? Share it in comments

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