Unlock Your Superhero Potential: Proven Ways to Increase TYPE 2b & 2X Muscle Fibres

I have a (un)healthy obsession with type 2 muscle fibres. My inner nerd fantasises about shrinking down to subcellular size and embarking on an excursion into someone's bicep to investigate the inner workings of these fibres. The primary method for developing type 2b/x muscular fibres is plyometric training. Plyometrics cause you to tire in seconds. There is a common notion that as we age, we should avoid plyometric activities. I hypothesise that this misperception is the primary cause of type 2 fibre waste with ageing. At 51, I have more Type 2 fibre than I did in my twenties! Even though this article is a rudimentary introduction to type 2 fibres, I am hoping it will kickstart or reinvent your health and fitness regime!

This explosive plyometric movement uses type 2 fibres.

Even among those who are thought to be the fittest people in the world or regular gym attendees, type 2 muscular fibres are overlooked and undertrained. Over the previous 20 years of research and practice, I've discovered and hypothesised that type 2 muscle fibre activation is one of the few keys to unlocking the majority of human health and lifespan advantages. As dungeon master, I order you to retrieve this key as a primary objective. The key opens the chest that houses the magic wand of hypertrophy (muscle increase). As usual, I'll attempt to summarise the knowledge that would fill a Tolkien-esque collection.

Please Miss, can you help me get ripped?

What are type 2 muscle fibres?

To answer this we need to look at the main fibre types.

Short answer

Type 1 = slow endurance muscle (mainly skeletal).

Type 2 = Fast & power muscle.

The long answer

Type I fibres, often known as slow-twitch. The colour red is caused by large levels of myoglobin and mitochondria. Responsible for repeated low-intensity contractions via aerobic pathways. Unless you conduct plyometric exercise, you will find more of this fibre in your postural muscles. Unfortunately, this fibre type dominates the western population, including exercise fanatics.

Type 2a, often known as fast twitch fibres, include a high concentration of mitochondria and myoglobin. They differ from type 1 in that they produce and consume ATP faster through aerobic and anaerobic metabolism. They are strong and rapid, but they fatigue quickly unless you are in peak fitness condition.

Type IIb and 2X muscular fibres. I like to refer to these as 'super fast twitch'. Low levels of myoglobin and mitochondria. Hence, they are white. They are completely anaerobic, producing slower ATP but breaking it down extremely quickly. Short, powerful pings!

Exercise science research into these muscle fibre types is still in its early stages. For me, the take-home message is that the combination of all fibre types has the capacity to cause muscular contraction throughout a steadily expanding range of speed. It goes without saying that this can improve overall fitness, agility, and coordination.

Movements and training techniques that target type 2 fibres.

Basically any explosive,'shocking', quick, and unpredictable motions, such as burpees, jumping push-ups, and transitioning from one plyometric activity to another, so the brain cannot detect a pattern. Modern dance, boxing, etc.

Hello good sir! Your type 2 fibres are making your body very happy!

Type 2s are activated through conventional resistance training and other activities, but they must be supplemented by the aforementioned to have a complete influence on health and fitness.

Anything medium to long distance or dynamically repetitious is a no-go. You will never receive the rewards. You will not receive the magic wand!

I'd like to take this a step further. Even among fitness practitioners who engage in plyometric exercise, the focus is almost always on the legs. The entire body must be trained explosively. You must find plyometric solutions for your entire body, just as we can exercise it dynamically or isometrically. For example, jumping push-ups for the chest and shoulders. Jumping tricep dips, etc.

Consider a fit runner who runs 60 km per week but does little supplemental training. Their upper body is underutilised, and hardly any of their body is trained using plyometrics. They are at a fraction of their health potential and will probably gain an injury at some point.

Genetic modifications (epigenetics) caused by activating type 2 fibres

Huge amounts of study need to be done in this area, which I believe will yield some groundbreaking results.

Researchers discovered that targeted acute explosive exercise can delay, pause, and prolong telomeres. HIIT (high intensity interval training) and plyometric sequences (such as leaping push ups, box jumps, and burpees) are particularly effective here. Telomeres function as a biological egg-timer of death. They are located at the ends of your chromosomes. This appears to be linked to muscular atrophy with ageing, resulting in the loss of type 2 fibres. Even though studies attribute the cause to a natural process, I hypothesise it is mainly due to a sedentary western lifestyle, particularly between the ages of 25 and 60. I know people in their mid-70s who are practicing plyometrics and strength routines that they did not undertake before the age of 65, and their muscular atrophy has reversed. Increased muscle mass also helps to prevent sarcopenia and a variety of other health risks, including obesity. Practical health benefits include being able to survive falls with less injury, having faster reaction times, and so on. This all contributes to increased survivability.

Type 2 activation occurs in some sports and leisure activity. AT ANY AGE!

Tendon & ligament strengthening.

Studies have demonstrated that the combination of muscle and tendon functioning together (muscle-tendon complex) gains more strength and suppleness with plyometric training than weight training or other 'regular' types of exercise. People tend to believe that explosive motions make you stiffer, yet the contrary is actually true. It is an area of research that I would like to pursue further. I have definitely grown more flexible, nimble, and faster as a result of intense training and developing my type 2 muscle fibre, than from mild exercise or stretching.

You don't have to go this far to activate type 2s! oooooo but now I want to do this!

Plyometric induced hormonal activation.

HGH (Human Growth Hormone) is one of the firecrackers that has been studied in explosive training. Type 2b/x fibre hungry training increases HGH. This is called an exercise-induced growth hormone response (EIGR).

HGH can:

1) Help to metabolise fat.

2) Increase the insulin like growth factor 1.

3) Promote the growth of bone, skin and cartilage.

4) Boost protein production.

5) Increase lean muscle mass.

6) Reduce the risk of heart disease.

7) Increase physical performance.

8) Increase skin thickness.

9) Aid faster injury recuperation.

To name but a few....

Studies have revealed that a single bout of intensive or acute exercise results in HGH levels increasing up to 100%. This may peak up to an hour after training. This is enormous. It is possible to have HGH levels higher than that of a 16-year-old for two hours if combined with being in a fasted state! The amount secreted is more closely related to the exercise's peak intensity than its length (Kavuran et al., 2025).

There is more work to do! There is a huge amount more to study in this area and I will add more information as the studies roll in!

In conclusion.....Include rapid explosive movements in your weekly exercises such that they account for at least half of your effort. Trust me, you will get enormous benefits at the muscular, organ, metabolic, and genetic levels!

ALWAYS CONSULT A DOCTOR BEFORE UNDERGOING ANY NEW DIET OR FITNESS REGIME.