So, today I wanted to discuss muscle hypertrophy (growth), but I also wanted to go over the three types of fibers that our muscles are comprised of and what type of training can improve each of them.
Muscles are made up of three different fiber types: Fast-twitch (FT), Intermediate, and Slow-twitch (ST).
Fast twitch fibers (Type IIx) are specialized for anaerobic metabolism.
They are recruited by the nervous system predominantly for rapid, powerful movements such as jumping, throwing and sprinting.
Type IIa fibers, also Fast Twitch, are called Intermediate fibers.
These fibers possess speed, fatigue, and force production capabilities somewhere between ST and Type IIx fibers.
They are also used for strength and power activities, but can sustain an effort for longer than the Type IIx fibers - up to 3 minutes in highly trained athletes.
Type IIa fibers are unique in that they are highly adaptable.
That is with endurance training, they can increase their oxidative capacity to levels similar to those observed in ST fibers.
Slow-twitch muscle fibers, on the other hand, are exceptionally well equipped for oxygen delivery and have a large quantity of aerobic, or oxidative enzymes.
ST fibers are designed well for aerobic glycolysis and fatty acid oxidation.
They are recruited primarily for low intensity, longer duration activities such as walking, jogging and swimming.
Muscle fiber distribution is determined to a large extent by genetic makeup.
All three types of muscle fiber are highly trainable, however.
They are capable of adapting to the specific metabolic demands placed on them.
A person who regularly does low intensity endurance activities improves his/her aerobic capacity.
All three types of of fibers will show improvement in aerobic ability, but the ST fibers will be the most responsive and show the most improvement.
If, on the other hand, short duration, high intensity exercise such as interval training is performed regularly, the capabilities of the FT fibers to perform anaerobically will be enhanced.
ST fibers are less responsive to this type of training.
Muscle growth, or chronic hypertrophy, is responsible for the strength gains experienced after a prolonged period of resistance training.
Hypertrophy is associated with structural changes in the size of existing individual muscle fibers (fiber hypertrophy), and to a lesser extent, in the number of muscle fibers which is called fiber hyperplasia.
Here are some recommendations for developing muscle hypertrophy: 1.
) Perform high-volume workouts that include several sets of many exercises for each major muscle group.
Split routines are typically employed because it gives the muscles the 72 hours of recovery time needed to repair/remodel.
2.
) The recommended training intensity for muscle hypertrophy is about 70 - 80% of your 1 RM.
I'm sure that there are several calculators out there to figure out your 1 RM, but at http://www.
cathe.
com, she has an excellent calculator and she lists several different exercises.
3.
) Most people can perform about 8 repetitions with 80% of maximum resistance and about 12 reps with 70% of 1 RM so it is recommended to use a rep range of 8-12 for muscle hypertrophy.
Keep in mind that this does not just mean counting to 12.
You should be completely fatigued by that last rep.
Also, successive sets with short rests further enhance the "pumped-up" effect, which appears to facilitate muscle growth.
4.
) Each muscle group may be trained for 12-16 sets of 8-12 reps with approximately 75% of maximum resistance.
For most exercises, it is recommended that you only rest for 30-60 seconds between successive sets.
5.
) Use a combination of free weights, machines, and cables to target all the muscle groups with an emphasis on isolation exercises.
Supersetting, or doing two exercises back to back with no rest is a great technique.
You can do opposing muscle groups or the same muscle group.
Breakdown training, or drop sets are another great way to completely fatigue the muscle.
And assisted training is an excellent tool for muscle hypertrophy.
With this technique, train to muscle fatigue, then receive manual assistance from a trainer/partner on the lifting phase (concentric muscle contraction) for 3-5 more reps.
This is so effective because you have to control the negative portion of the exercise (eccentric contraction), where the majority of growth occurs.
Muscles are made up of three different fiber types: Fast-twitch (FT), Intermediate, and Slow-twitch (ST).
Fast twitch fibers (Type IIx) are specialized for anaerobic metabolism.
They are recruited by the nervous system predominantly for rapid, powerful movements such as jumping, throwing and sprinting.
Type IIa fibers, also Fast Twitch, are called Intermediate fibers.
These fibers possess speed, fatigue, and force production capabilities somewhere between ST and Type IIx fibers.
They are also used for strength and power activities, but can sustain an effort for longer than the Type IIx fibers - up to 3 minutes in highly trained athletes.
Type IIa fibers are unique in that they are highly adaptable.
That is with endurance training, they can increase their oxidative capacity to levels similar to those observed in ST fibers.
Slow-twitch muscle fibers, on the other hand, are exceptionally well equipped for oxygen delivery and have a large quantity of aerobic, or oxidative enzymes.
ST fibers are designed well for aerobic glycolysis and fatty acid oxidation.
They are recruited primarily for low intensity, longer duration activities such as walking, jogging and swimming.
Muscle fiber distribution is determined to a large extent by genetic makeup.
All three types of muscle fiber are highly trainable, however.
They are capable of adapting to the specific metabolic demands placed on them.
A person who regularly does low intensity endurance activities improves his/her aerobic capacity.
All three types of of fibers will show improvement in aerobic ability, but the ST fibers will be the most responsive and show the most improvement.
If, on the other hand, short duration, high intensity exercise such as interval training is performed regularly, the capabilities of the FT fibers to perform anaerobically will be enhanced.
ST fibers are less responsive to this type of training.
Muscle growth, or chronic hypertrophy, is responsible for the strength gains experienced after a prolonged period of resistance training.
Hypertrophy is associated with structural changes in the size of existing individual muscle fibers (fiber hypertrophy), and to a lesser extent, in the number of muscle fibers which is called fiber hyperplasia.
Here are some recommendations for developing muscle hypertrophy: 1.
) Perform high-volume workouts that include several sets of many exercises for each major muscle group.
Split routines are typically employed because it gives the muscles the 72 hours of recovery time needed to repair/remodel.
2.
) The recommended training intensity for muscle hypertrophy is about 70 - 80% of your 1 RM.
I'm sure that there are several calculators out there to figure out your 1 RM, but at http://www.
cathe.
com, she has an excellent calculator and she lists several different exercises.
3.
) Most people can perform about 8 repetitions with 80% of maximum resistance and about 12 reps with 70% of 1 RM so it is recommended to use a rep range of 8-12 for muscle hypertrophy.
Keep in mind that this does not just mean counting to 12.
You should be completely fatigued by that last rep.
Also, successive sets with short rests further enhance the "pumped-up" effect, which appears to facilitate muscle growth.
4.
) Each muscle group may be trained for 12-16 sets of 8-12 reps with approximately 75% of maximum resistance.
For most exercises, it is recommended that you only rest for 30-60 seconds between successive sets.
5.
) Use a combination of free weights, machines, and cables to target all the muscle groups with an emphasis on isolation exercises.
Supersetting, or doing two exercises back to back with no rest is a great technique.
You can do opposing muscle groups or the same muscle group.
Breakdown training, or drop sets are another great way to completely fatigue the muscle.
And assisted training is an excellent tool for muscle hypertrophy.
With this technique, train to muscle fatigue, then receive manual assistance from a trainer/partner on the lifting phase (concentric muscle contraction) for 3-5 more reps.
This is so effective because you have to control the negative portion of the exercise (eccentric contraction), where the majority of growth occurs.