Various types of muscle fibers form each muscle.  To increase strength, all types of muscle fibers should be worked during a training session.  For some specific exercise combinations that use all types of muscle fiber, read this article on an exercise plan.  The two primary fiber categories are fast twitch and slow twitch and fast twitch fibers consist of Type A and Type B fibers.  The majority of muscles consist of about half fast twitch and half slow twitch fibers.  Your training program should train both types of fiber to use all of the fibers in any given muscle and make the muscle bigger.

Fast twitch muscle fibers work anaerobically – they are exercised when you need short bursts of strength or speed.  These muscle fibers use the energy available in your body.  Fast twitch muscle fibers fatigue faster than slow twitch fibers because the fast twitch nerves fire faster.  Fast twitch muscles are used when a sprinter runs, using a lot of power for a very short time.

Fast twitch Type A muscle fibers are transitional fibers and use both aerobic and anaerobic metabolism.  These muscle fibers are used for activities that are relatively short, but not at full speed.  Fast twitch type B muscle fibers use anaerobic energy only.  Type B fast twitch muscle fibers have a contraction rate faster than any other muscle fibers so they fatigue very fast.  You will use your Type B fast twitch muscle fibers when you require a lot of energy really fast. 

Slow twitch muscle fibers use aerobic metabolism.  These fibers contract slower and can work for a long time, but they do not generate a lot of power.  Oxygen rich blood runs through the many capillaries found in slow twitch muscle fibers providing them with the aerobic energy required to perform.  The slow twitch muscle fiber is used for medium to low intensity exercises that can be executed over a long period of time.  Slow twitch muscles are used when you train for a marathon, ride a bike many miles or go hiking.

 Your strength training workout should work all three types of muscle fibers so you can have the energy you want for whatever type of exercise you choose to do.  You can find reviews of programs that adhere to this principal at Turbulence Training Review and No Nonsense Muscle Building Review.   There are a lot of programs out there, but next I’ll give you some ideas on how to train each muscle type – you could easily make up your own program.

The completely anaerobic Type B fast twitch muscle fibers can be trained with exercises that require an all out effort for a short period of time.  Lift the heaviest weight you can lift for one repetition to fatigue or sprint at full speed to fatigue.  Type A fast twitch muscles are worked when you lower the force and increase the time – run fast for 20 – 30 minutes or lift a weight that allows you to complete 6 – 10 repetitions to fatigue.  Slow twitch muscles are strengthened when you train for endurance.  Run for an hour, swim a lot of laps, lift a weight small enough so you can do 6 – 10 repetitions for three sets.  This training is necessary to build the entire muscle even though it will take more time than the training for fast twitch muscles.

Tags: build muscles, muscle building, strength training, Strong Muscles