What is Hypertrophy Training?

Article by Rebecca Ireland

Hypertrophy with regard to muscle and exercise/training is defined as "an increase in the size of muscle cells" (Quinn, 2021)

In essence, the theory of hypertrophy training is to make muscles bigger by undertaking training with a load that will facilitate the process of muscle hypertrophy. In addition to the training itself, many other factors will determine the amount of hypertrophy achieved. Genetics, macronutrients intake, calorie intake, age, gender, and hormone levels will all play a factor when it comes to achieving hypertrophy.


Regardless of the above factors, how is muscle growth achieved by following a hypertrophy training program?

A muscle is made up of fibres, that through nerves being triggered, will contract, or relax and is required to move parts of the body. The body is able to repair itself in most circumstances. If we think of a muscle as being a piece of string made up of hundreds of tiny fibre strands, when putting a load through that string, if the load is heavy enough or if the string is repeatedly made to take a load, some of the tiny fibre strands within the piece of string will break.

If the human muscle were like that string, we would say that lifting load would make the muscle weaker, and although this is true for the immediate moment after the lift, the duration of weakness after is dependent on multiple factors. These are the same factors that determine a person’s hypertrophic response within the human body. The fibres that are damaged during hypertrophy training will not only repair, but they will also enlarge. This is due to the body’s sense of self-preservation which will determine that there is requirement for the particular muscle to be bigger/stronger, resulting in hypertrophy.

So, hypertrophy training is used to increase muscle. By doing so body fat has a larger surface area to cover, meaning that the body will appear leaner. The lower body fat a person has, the more visible their muscle structure will be. However, high volume weight training will increase fitness and gain an aerobic and anaerobic response, but during this, some (not many) muscle fibres will break, and the body will repair them. This is still hypertrophy training of a sort!

How do we achieve hypertrophy in the body to elicit this growth effect?

We firstly we need to make the muscle move with a load/weight to cause the fibres to damage, which will then repair and grow. The load/weight needs to put stress on the muscle fibres to make the ‘micro tear.’ However, the heavy weight and the hypertrophic response is not optimal in the same way as that of a lighter load would be. To get the best hypertrophic response, all 3 pillars when hypertrophy training should be covered.

The 3 Pillars to Hypertrophy Training

Heavy Mechanical Loading (HML)

HML training requires you to push toward the limit of load capability, but this is NOT maximal effort! In order to be effective, we need to push with HML close to, but not to complete failure. HML should be carried out in exercises that use multiple joints/compounds moves e.g., bench press, bent over rows, squats and deadlifts. Repetition range for theses HML exercises are best in the 6-12 range (hypertrophy). Anything below 6 and the hypertrophic response reduces. Anything above moves into the Time Under Tension or Metabolic Stress categories.

Time Under Tension (TUT)

TUT puts the muscles under tension for a longer time. The hypertrophic response is greater in the eccentric part of a lift (the down part) then in the actual lifting (concentric phase). TUT while the muscle is under tension of load will create more micro tears to the fibre, giving the best hypertrophic response.

As previously mentioned, the body repairs and adapts, meaning it gets used to weights we lift. Therefore, in order to continue to be able to get a hypertrophic response, we need to continually adapt the load by increasing it. In order to do this, we have to increase strength as well as durability through the joints, ligaments, and tendons in the body. This is the reason any real hypertrophy training program is under pinned with HML. The rep range for TUT is 10-15 reps but tempo is key, e.g., controlling the weight for 3 seconds up and 3 seconds down. Due to the TUT this will limit the weight that can be lifted.

Metabolic Stress (MBS)

Anyone who has done weight training has either heard of or experienced the “pump”. This is an important part of hypertrophy training. The body pumps blood into the muscle to start the repair process of the micro tears. It also aids in flushing out lactic acid built up in a muscle during hypertrophy training, helping reduce DOMS (delayed onset muscle soreness).

The rep range for MBS is 20-30 reps and usually involves isolation movements focusing on a particular body part, as opposed to HML which is for multi-joint compound movements.

Hypertrophy Training Balance

It is important that a hypertrophy training program is balanced, as it will allow all muscles to achieve a similar stimulus to ensure the body doesn’t become imbalanced, potentially causing injury. For example, if a person trained their chest at an intensity or frequency far greater than the upper back, the strength of the chest muscles having inversely outgrown that of the upper back muscles, it could affect their posture, which could lead to back injuries. Additionally ensuring that muscle groups are rested enough to repair is equally important to allow the process of hypertrophy to be complete.

In Conclusion

Hypertrophy training is an excellent method used to increase muscle and make the body appear leaner. It is important to follow the 3 pillars of hypertrophy training to achieve the best hypertrophic response and result, and to remember to use a balance program to reduce risk of injury. With hypertrophy training the body is using energy to repair, rebuild, and grow, and you continue to burn calories for 72hrs after you finish your resistance session.

Editor’s notes - hypertrophy training 

Following on from a very interesting hypertrophy training article there are some key elements on muscular hypertrophy to expand on. These include going through differences in the hypertrophy vs strength training discussion, hypertrophy workout examples, training volume for hypertrophy and hypertrophy rep range. It is also to be explored as to what goes into a hypertrophy programme and what makes an effective muscle hypertrophy workout.

Comparing strength training to hypertrophy training

It is a common question for any beginner to ask what is hypertrophy? Or how do I do hypertrophy training? The more experienced gym-user may ask more in-depth questions about hypertrophy training like how does a certain muscle hypertrophy training plan work?

The hypertrophy definition is simply that muscle hypertrophy is about the muscle size increasing. A well-designed muscle hypertrophy workout will lead to this.

Some beginners may actually get confused with the hypertrophy vs strength differences – they are two different things! A hypertrophy workout leads to bigger muscles whilst a strength workout improves the force generated by the muscle.

A well-designed hypertrophy programme is important to elicit change – for example without the correct hypertrophy rep range, then a hypertrophy workout may be ineffective. Training volume for hypertrophy is also a very important part of a hypertrophy programme and this is why the hypertrophy rep range and set range are correct.

To increase the size of a muscle hypertrophy must be planned for accordingly. A beginner would not just start with a muscle hypertrophy workout, more so they would start with a muscular endurance base as per the strength training pyramid.

When asked what hypertrophy is when compared to strength, it is important a Personal Trainer can clearly define hypertrophy compared to strength. In fact, the hypertrophy vs strength differences are plentiful. As previously touched on, muscular hypertrophy is all about increases in size of the muscle whilst muscular strength is about increases in force.

A Personal Trainer who compares strength training to hypertrophy training with clients should be able to define hypertrophy vs strength training to ensure that they are coaching their clients correctly. It is imperative that a muscle hypertrophy workout is based on a well-designed hypertrophy training programme. This is the only way that hypertrophy training can be effective.

Effective hypertrophy workout examples

Effective workout examples for hypertrophy training include utilising the following exercise examples at various points throughout a hypertrophy training programme. Any of these exercises could be used as part of a muscle hypertrophy workout and a Personal Trainer would be able to advise if in doubt. (Please note this is by no means an exhaustive list of hypertrophy training exercises. Please note the correct hypertrophy training volume and hypertrophy rep range would need to be applied to the below exercises to elicit muscular hypertrophy.

  • Chest press (bench press) – will lead to muscular hypertrophy in the pectorals and triceps muscle
  • Lat pulldown – for muscle hypertrophy in back and bicep muscles
  • Back squat (ideally with a barbell) – hypertrophy for quadriceps, glutes
  • Leg Press – muscle hypertrophy workout for quadricep, glutes
  • Deadlift – muscular hypertrophy for glutes, hamstring, back, trapezius
  • Bent over row – muscle hypertrophy for lats, trapezius, rhomboids, deltoids
  • Overhead press – muscular hypertrophy for pectorals, deltoids, triceps, trapezius
  • Standing dumbbell bicep curl -muscle hypertrophy workout for biceps
  • Frontal and lateral raise – muscular hypertrophy for deltoids

To make hypertrophy training effective the correct hypertrophy rep range must be used. The correct training volume for hypertrophy must also be factored in. Muscular hypertrophy training is typically 3-4 sets of 6-12 reps. A good muscular hypertrophy programme should include such a hypertrophy rep range. In contrast a strength training programme may have 3-5 sets of 2-6 reps, so a higher resistance than hypertrophy training. It is interesting to note how the training volume for hypertrophy differs from that of strength training – this adds further to the concept of hypertrophy vs strength differences.

For any hypertrophy workout it is important that progress is measured so that muscular hypertrophy and hypertrophy definition can be charted. A hypertrophy programme that is not measured is difficult to evaluate. Hypertrophy definition in muscles will only happen if the target muscle hypertrophy workout adheres to the correct hypertrophy rep range and correct training volume for hypertrophy.

This article has explored hypertrophy training and focussed on both the hypertrophy vs strength training debate as well as placing focus on hypertrophy workout ideas including hypertrophy rep range and what makes an effective muscle hypertrophy workout including hypertrophy training programme ideas and focus on the correct training volume for hypertrophy. It is hoped that this has been a useful read for those interested in hypertrophy training.

Summery of key points:

  • What is hypertrophy compared to strength is a common question for beginners
  • We can define hypertrophy as an increase in muscle size
  • Muscle hypertrophy training has different sets and reps to strength training
  • Hypertrophy vs strength represents key differences
  • A hypertrophy workout needs to have the correct hypertrophy rep range
  • A well designed hypertrophy program will lead to muscular hypertrophy
  • A hypertrophy training programme can lead to hypertrophy definition of muscles
  • Training volume for hypertrophy must be correct to lead to muscle hypertrophy
  • A muscle hypertrophy workout can include many common exercises


Hypertrophy training or taking part in any kind of hypertrophy workout or hypertrophy training programme should always be as per the guidance of a qualified exercise professional. The hypertrophy rep range and training volume for hypertrophy should always be advised by a Personal Trainer or strength coach. Before starting any kind of hypertrophy training programme, a PAR-Q should be completed and GP consent gained if needed.

FitnessFitness trainingGymGym workHypertrophyWeight-trainingWorkout

Leave a comment

All comments are moderated before being published