Training Tips, Know Your Muscle Fibre Type

When training or bodybuilding, it is crucial to know which group of muscle fibre is dominant in your body.

Fast twitch fibres are generally responsible for explosive strength and power, which would be true in the fact that most sprinters have muscle composition with predominantly fast twitch fibres.

Slow twitch fibres are generally fatigue resistant and provide sustained energy increasing endurance, typically found in long distant and marathon runners.

Generally, most individuals fall into one of three categories; predominantly fast twitch, predominantly slow twitch or an average mix of the two.

Determining which category one falls into gives you the advantage of being able to personalise a training programme to achieve your body‘s natural potential without the need to buy steroids.

There are a few ways to evaluate muscle type and find which group you fall into.

A muscle biopsy is possible. This requires removing a small amount of muscle tissue and have it examined under a microscope where the fibre types can be evaluated. Not practical or economical since this is not provided on the NHS.

The easiest way to test would be to head to the gym and test your muscular endurance. Perform a one rep max with the highest weight possible for a controlled repetition. After that, take five minutes  rest and then see how many repetitions you can perform with 80% of your one rep max weight.

Generally, if you can perform more than about 15 reps then you can assume you are composed of mainly slow twitch fibres. If you fatigue before you  do about 10 reps, then you can assume you are composed of mainly fast twitch fibres.  And if you perform around 10-15 reps, then you can assume you fall some where in the middle with a balanced composition between fibre types.

Knowing your fibre type will allow you to develop your training programme to maximise your potential. Many highly successful body builders have a predominant amount of fast twitch fibres, this means they exhaust their muscles with a relatively low number of repetitions.

Throughout the history of bodybuilding, strength and power training has always been based upon low reps with high weights. This has been preached religiously and yet there are still many individuals training in this fashion without much success.

Counting repetitions has always been a mainstay of strength training for decades. The focus on hitting between 6-8 reps while taking the muscle to fatigue has always been around. However, the actual time that the muscles are worked for is actually more important than the amount of repetitions.

To maximise increases in both strength and size, an exercise must be performed for a certain amount of time at a high level of intensity.

This time changes depending on which muscle type category you fall into.

For those with predominately fast twitch fibres, shorter time frames are beneficial. So around 40-50 seconds for upper body and 50-70 seconds for the legs.

For those with predominately slow twitch fibres should train for a slightly longer duration. Around 60-90 seconds for the upper body and 90-120 seconds for the legs.

If you fall in the average composition of muscle fibres, a mid range time frame is suitable, 40-70 seconds for the upper body and 60-90 for the legs.

It is not generally practical to monitor timeframes whilst training, looking at a stop watch during a set on a bench press isn’t ideal. So take this knowledge into the gym with you and try to train your muscles the best you can to maximise your gains.