View Full Version : SLow and Fast twitch muscle groups

02-25-2011, 06:10 PM
Its generally accepted that Muscle fiber groups can be broken down into two groups, Slow twitch (type 1) and Fast twitch (type 2). Fast twitch muscle fibers can be broken down further into sub groups but for todays discussion we are going to talk about just slow and fast twitch fibers. These distinctions seem to influence how the muscles respond to certain types of training. Human muscles contain roughly a 50/50 split of slow and fast twitch muscle fibers in most of the muscles that are used for movement. SLow twitch (type 1) muscle fibers are efficient at using oxygen to generate more fuel (known as ATP) for continuous, extended muscle contractions over a long time. They fire more slowly than fast twitch muscle fibers and can go for a long time before they fatigue. Think of them as a long distance runner who seems to be able to run and run before getting tired thats an example of slow twitch. Because Fast Twitch fibers use anaerobic metabolism to create fuel, they are much better at generating short burst of strength and speed than slow muscles. However they fatigue much quicker than the slow twitch fiber would, they generate the same amount of force and strength as slow twtich fibers but tire much quicker which led to their name Fast twitch. Think of it this way if your a sprinter you'd want more out of your Fast twitch muscle group than your slow twitch group because you need the speed now.
Now for training purposes it would make sense to want to tire and build both of these muscle fibers for an all around quality muscle growth. How can we do this?? Well there is still raging debate as to what is the best method but it would seem to make sense to train in two different fashions in order to hit both groups. Short intense workouts (perhaps doing nothing but suspersets with limited rest) for no more than 30 minutes to try and tax the Fast twitch fibers. And your standard 45 minute to an hour workout of controlled lifting with plenty of rest for the overall slow twitch. I would venture to guess that if you try an incorporate both of these styles on a regular basis you are doing your best to insure overall muscle growth:cool:

02-25-2011, 06:47 PM
This takes me back to my personal trainers course. I was always taught a good way to hit th range of muscle fibres is to do a sort or pyramid training where you lift say 8 reps of your 8RM then drop the weight a little and next set do 12 reps of your 12 rep max then drop the weight and next set same with 15 reps. You can even do 20 after that. Teaches your muscles a mix of strength and endurance. I don't have personal experience with this bit it's what I was taught.

02-25-2011, 06:49 PM
Limo, can slow twitch muscles grow on size?

02-25-2011, 08:45 PM
Ahh hhaa the million dollar question- The answer is yes although both fiber types respond positively to strength training, the fast twitch types experience greater increases in muscle size and strength, and so they may obtain greater results. But there are so many variables and factors that are involved in muscle growth such as length of muscle and genetic capabilities, and the subjects diet all are major players

02-25-2011, 10:26 PM
Long threads really need paragraphing...

I cant read it like this =(.

02-25-2011, 10:38 PM
Good stuff Limo! 3 months ago I started a "high rep low weight" routine hoping to target those muscles. I figured I would just lean up and get quicker but I actually saw some size gains in a couple areas, - mainly legs traps and arms . There's no doubt that heavy weight is very important to gaining size but switchin' it up every once in while is good especially when you ratchet up the intensity. Thanks for the post.

02-25-2011, 10:44 PM
I like to mix up heavy resistance and low weight endurance on my abs.

02-26-2011, 01:17 AM
I change it up a bit to make sure I hit all the fibers.... I'll do drop sets, Sets of 15, I'll do a 4-6 rep range and thanks to OL'Safelife I do pause reps ( Chest) Sore something nasty afterwards.....

02-26-2011, 05:03 PM
Great thread Limo Thanks Homie.