10 second rule - good point about training type IIB muscle

Type IIB muscle is the fastest of the fast-twitch muscle with very short fatigue time of around 10 seconds.

Chad Waterbury makes a good point in the article below: if you just limit your sets to 10 seconds, regardless of whether you are lifting less than a heavy load, you will target type IIB. Another way is to stop a set when the speed slows down noticeably, for me this is easy I noticed the slow-down as my IIB muscles fatigue pretty clearly.

I personally have a lot of type IIB muscle, I am definitely a fast-twitch guy not an endurance guy. Having said that, it is easy to sort of "bypass" the type IIB muscle when lifting by doing sets that last longer than the IIB muscle can peform, namely longer than 10 seconds. If you go by many of the standard conventional recommendations which say to do 8-12 reps or 12-15 reps etc. this could easily put you over 10 seconds.

Prior to reading this I have had success hitting IIB muscle through heavy weight pullups and dips. But Waterbury is stressing that the weight does not have to be heavy, it can be lighter just lifted fast over 8-10 sets and still target IIB muscle.

I noticed and practiced this principle in running: just by doing it I realized that to hit the type IIB muscle you do *not* have to run all-out sprints like some would suggest, which blows your CNS out pretty quick. Sure, all-out sprints are an intense cardio workout, but we are talking about hitting IIB leg muscle not cardio muscle. In fact, if you just run all out sprints (as many suggest and as I have tried in the past) your CNS will be toast way before your leg muscles really get the workout you are looking for.

Instead, just running sort of "low-key" sprints--still sprints but not all out--but running a lot of them like 8-10 will work the type IIB muscle deep. The 10 second rule applies here, just run sprints for 10 seconds or less even if they are not all out, and do a lot of them.

In general, I find that most "muscle building" advice out there is *not* really geared toward the minority who have a large amout of IIB muscle but to the majority who have IIA. And then there are the running and biking magazines for the type I endurance guys...

10 second rule
http://chadwaterbury.com/the-10-second-rule/