For newcomers to this forum, these P&Ps are Propositions, not facts or
dogmatic proclamations. They are intended to stimulate interaction among
users working in different fields, to re-examine traditional concepts, foster
distance education, question our beliefs and suggest new lines of research or
approaches to training. I look forward to responses from anyone who has
views or relevant information on these topics.
PUZZLE & PARADOX 122B
Current preoccupation with the role of muscle fibre type in determining
physical performance may be misleading and only of limited relevance.
A great deal of sport specific training theory seems to be based heavily on
the ratio of specific muscle fibre types, but one never hears about the
simultaneous effects of different muscle fibre types and joint levers on
To be more specific, let us consider twin lifters A and B with exactly the
same bodymass and all things other than fibre type being much the same. Twin
A has a very high proportion of fast twitch fibres (say, Type IIb), but has
relatively poor leverage systems, since the attachment of his muscle tendons
to their relevant tuberosities (bumps on the relevant bones) are quite close
to the joints. Twin B has a lower proportion of fast twitch fibres, but has
significantly superior joint leverages.
This means that it is possible that the better leverages enjoyed by twin B
might well compensate so effectively for his lower percentage of fast fibres
that he could be stronger and more powerful than his brother A, with all of
his apparent fibre type advantages.
In other words, we are not really justified in relying too heavily on
proportions of muscle fibre types in determining how adequately one is
equipped for a given type of activity. At the very least, we would be
advised to examine fibre types as well as estimates of leverages.
Without an clear answer to this problem, it would then seem that we cannot
really make any definitive correlations between strength/power performance
and certain muscle fibre types. There appears to be something vital missing
from all the discussions on fibre type relevance, so that we may need to pay
a little more attention to the possible role of other contributory factors in
determining trying to relate muscle type to physical performance.
Comments or further information from anyone?
Dr Mel C Siff
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