Is the sarcoplasm usefull to speed?

[star61]

@lkh

Before getting into pennation and stacked sarcomeres, these are the real numbers from the paper martn posted about the effect of training at 1-3 reps (max strength), body builders training at 6-12 reps and 60-70% max (the D’Antona paper I mentioned above), and controls. This is for MHC isoform:

MHC 1-3reps 1-3reps 6-12reps controls
Isoform after before

MHC slow 14% 18% 33% 48%

MHC 2A 67% 49% 42% 49%

MHC 2X 17% 33% 20% 4%

You can’t directly compare the numbers, as the muscles biopsied were different (triceps brachii vs vastus lateralis), but the difference in trend is dramatic. It’s quite clear that there was a significant shift of IIx => IIa in the 1-3 rep study, while there appears to be a shift from I => IIa => 2X in the 6-12 rep study.

There are a number of studies that have documented type II fiber transitions for different rep ranges. These include not just the 1-3 reps, but also training at 6-8 reps (females, to failure) and a study in the Journal of Applied Physiology specifically to enhance SSC by means of plyometrics. ALL of these studies used high intensity (max force) and ALL of these studies documented a transition of IIx => IIa, which is also what one gets for sprinting unless the intensity is pulled back for competition (what Charlie says about not more than 95% applies here). By comparison, the D’Antona study of bodybuilders used 6-12 reps @60-80% 1RM, which implies a buffer of 10-15%.

Regarding reps and sarcomeres, I have not seen any studies suggesting reps >15 for sprinters (not competitive bodybuilders), however 8-15 reps falls within the range for both sarcomere hypertrophy and sarcoplasmic. Note that the strength program for Maurice Green on this site used 10 reps for both bench and squats, and 15 reps for secondary exercises.

Published studies for leg morphology suggest that hypertrophy methods affect primarily the upper thigh, and not the lower thigh, and only partially the middle thigh. Thus hypertrophy methods in the sarcomere region, such as 8-10 reps/set (but with a buffer) would appear to be increasing the number of sarcomeres stacked more than the diameter of the fibers, which is what you seem to want as a sprinter.

Extremely interesting post. I actually came across the papers Nikoluski mentioned a few days ago when I was doing a google search looking for papers correlating 40yd times to 100m times. Didn’t find that, but found the papers mentioned. I scanned them quickly and must have missed the part about the rep ranges but I do remember the part about upper thigh hypertrophy. I’m going to read these papers again…this is a most interesting discussion because our current rep range on most primary lifts is 2-3.

[R3N3GAD3]

I thought Type I > Type II conversion, and vice versa, wasn’t possible?

[Goose232]

@lkh

these studies used high intensity (max force) and ALL of these studies documented a transition of IIx => IIa, which is also what one gets for sprinting unless the intensity is pulled back for competition (what Charlie says about not more than 95% applies here). By comparison, the D’Antona study of bodybuilders used 6-12 reps @60-80% 1RM, which implies a buffer of 10-15%.

Thus hypertrophy methods in the sarcomere region, such as 8-10 reps/set (but with a buffer) would appear to be increasing the number of sarcomeres stacked more than the diameter of the fibers, which is what you seem to want as a sprinter.

What do you mean by “buffer”?

Do you mean they are not doing the set to failure?

E.g;
8-10 reps with a weight you could do 10 - 12 reps with?

What does “BUFFER” mean guys?

[Jstu3565]

yeah you have the right idea. Leave a little in the tank during each set.

[martn76]

@mortac8

So should we avoid weights too if we don’t want IIb to IIa conversion?

Hello Mortac8,

If you read my past posts you will realise that I am into fiber conversion and its causes. I have come to a conclusion after studying hypertrophy and fiber conversion. Fiber conversion from IIb to II a is NOT A BAD THING in fact you WANT IT, YOU NEED IT. Hypertrophy of prime movers in an event is needed especially the hamstrings in sprinting. Rest, such as that experienced in the 10 day taper will take care of re-transformation. You will get an overshoot of IIb during the taper. Muscles are plastic. Some people are SO lucky because their make up allows some slow fiber to convert to type IIa or at least mimic the qualities of IIa twitch times. Train properly don’t be afraid of, or worry about fiber conversion ( as I was when I came across the phenomenon almost 10 years ago), it is a good adaptation and it is needed. Its a case of one step back two steps forward.

[martn76]

@R3N3GAD3

I thought Type I > Type II conversion, and vice versa, wasn’t possible?

Muscles are very plastic and will change according to demands. Bi directional conversion where type I converts to IIa and IIb also to IIa has been documented in humans and is one of the distinguishing features of talented athletes. In fact, physiologists were disappointed when they managed to take biopsy samples from a group of good sprinters and discovered a large majority of IIa and hardly any IIb.

[Pioneer]

My limited understanding of a fiber type drift/shift from IIa to IIb is only possible via complete rest from previous strength/power training or at least tapered training.

What I recall reading years ago, was that the most effective, productive strength programs of even top olympic weightlifting teams and athletes still resulted in mainly IIa results from biopsies. Only after a period of either complete rest or significantly tapered training, did this shift to IIb take place.

Perhaps the article is still here but I recall the article by Carl Johnson on his former athlete Jonathan Edwards getting into this subject(fiber shift) a bit due to JE’s forced long layoff from training due to Epstein-Barr syndrome(?) years back.

Ironically, there is an article on the training of yet another triple jumper, Jadel Gregorio of Brazil,(just recently jumped 58’ 8 3/4")which discusses the same. Both make reference to the work of Gunter Tidow on the subject. I do believe the article by Gregorio’s coaches Nelio Moura and Tania Fernandes de Paula Moura was/is available at coachr.org.