Thread: toning/slow twitch.. ?

I do not think you understand what slow twitch and fast twitch muscle fibers are.

read these two articles:
http://www.ironmagazine.com/article44.html
http://www.ironmagazine.com/article14.html

Working only the slow twitch fiber will not make your mucsles smaller. However, you would only be developing about half the fibers in a given muscle group. This assuming you are truely targeting the slow twitch fibers with high reps.

In a very general sense, the calfs and forearms have many more slow twitch fibers than fast twitch. And the deltoids have slightly more slow twitch than fast twitch. The remainder of the major muscles (back, upper legs, chest, and arms) are made up of more fast twitch fibers than slow twitch. It is something like a 55/45 ratio (a very general statement here). So it is not like a overwhelming degree of fast twitch. Understanding the domanint fibers in a target muscle will (or at least should) dictate the rep range you work the muscle. For fast twitch the mass building range is 5-15 reps and for slow twitch it is more in the relm of 10-20. So to hit as many of the fibers as you can you should work the muscle group with weight that will fatigue the fibers in all portions of the range.

If you are trying to build mass, you should try and set up your routine to cover the whole rep range or at least spread the exercises around the rep ranges as best you can.

First of all, toning is not achieved through the usage of low weights at very high repititions. All this does is increase muscular endurance. Toning is a function of lower bodyfat levels. Increased muscle mass does help reveal the muscles at higher bodyfat percentages, but hypertrophy is going to be tough to achieve with 5 pound dumbells.

The slowest muscle fibers are activated first. When you are doing your 1RM, you are using slow twitch fibers; you are just using fast twitch fibers in addition to the slow twitch fibers.