Quoting Martn76 from another current discussion (“RFD and Concentrated Loading”) gives occasion for a new one.
The following is from “Running.Biomechamincs and Exercise physiology applied in practice” by Frans Bosch and Ronald Klomp (2001):
“The reasoning that FT muscle fiber will provide speed,and thus good performance,in a sprint is not totally valid.ST fibers,which offer the possibility to avoid the rise latency,are also suited to reactive muscle work.
This idea finds support in the fact that ST,in contrast to FT fibers have stronger Z-discs and thus can absorb larger external forces.Moreover,because they not only turn on,but also turn off more slowly,ST fibers are able to maintain muscle morphology,which is also important for sprinters.(Ingen Schenau et alt.1984,Jones & Round 1990,Bobbert et alt. 1996).”
This is a roundabout of seeming contradiction;
A) slow twitch may hold onto morphology a bit longer, but fast twitch are bigger in the first place. 2. Fast twitch hypertrophy is more associated with myofibrilar hypertrophy which I 'm sure lasts longer than sarcoplasmic hypertrophy.
B) However, some Germans claim to have done a test on Ben Johnson which suprised them as to the amount of slow twitch fiber. Higher than expected.
C) If slow twitch fiber was so good, I 'd be the Olympic champon and you would all be watching videos of my performances.
According to my current knowledge, if someone have read Noakes book, marathon runners depend more and more on FT fibers, thus the better the long jump and triple jump in marathon runner the better the result…
On the other hand, it may seems that ST fiber may have their purpose in running… Very interesting thread… keep on!
(As most of the other possible factors emerging from the paragraph and study above which pass completely unnoticed apparently,while we are now informed of the presumed share of ST of someone here… )
Its also interesting to note its influence/role/observation in training and the fact that empahsis must be placed on what we have not simply what we wish to train - which have very valuable influences on regeneration IMO
Well I can tell you that more FT is perhaps not better. Nelli Cooman was 80% FT and struggled in the 100m as a result. Of course her 60m time was exceptional.
It’s a jump to conclude:
A: That she was 80% FT, because of the patchy nature of the fibre distribution making biopsies problematic.
B:That her FT proportion was, in any way, related to her lack of success over the 100m.
Well of course at the time the Germans would have been rather Interested at the amount of slow twitch. Gee, even these days at certain places in the world they would be amazed. But, for all of us that know how much Tempo training was done by Ben J all them yrs ago, we should not be suprissed by how much ST fibre was developed, and is developed via tempo running.
A few yrs ago now, i have heard that for 5 and 10k runners to be successfull in the international areana, the ability to have and use FT fibres is as necassorry as ST fibres. A ratio of appox 50/50 ST/FT and both Fibres worked in a concurrent program is a must. And thats for up to 10k…
One can see, that during the actual sprint itself, ST fibers may provide a minor effect (stabilizing and what else?) but the main effect of the ST for a 100m guy, would be in training, warming up (increasing temp and electrical ability, nutrition flow and blood flow to the FT fibres) and for recovery between speed sessions and races.
BTW, always view this sort of claim about top athletes with suspicion. Do you really imagine top athletes travel the world and stop their training and competing to participate in hair-brained and painful studies, so some clown they don’t even know can write a paper??
Yes, there are means to see FT in muscle through MRI and that’s how they know that the distribution is patchy but i don’t know the details- just enough to confirm what I already know, which is:
A: If you’re fast, who gives a shit what the fibre ratio is?
B: If a man in a lab coat approaches you with a huge hollow needle, run like hell in the other direction!
I forgot point C:
If you see that guy with the biopsy needle coming up behind you, you might find that you can run a lot faster than you ever thought possible!
I think the fast twitch/slow twitch debate is too simplistic. I mean, how much do we really know about these fibers? Just as an example of what I mean, on one hand we are told that aerobic work, due to the impulses being submaximal, will lead to fiber type conversion(fast to slow) but on the other hand, like Charlie says, aerobic work can build up better capillary density, heating the muscle and allowing for less electrical resistance, which presumably would give it characteristics of fast twitch.
Does this mean that some aerobic work actually causes muscle fibers to take on characteristics of fast twitch? How do we reconsile that while knowing that we were always told that aerobic work caused fast to slow conversion? Even assuming that conversion to slow twitch was something to be avoided, if the fiber is slow twitch but takes on the characteristics of fast twitch is this bad? Does it really matter at all?
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