Donovan Rebbechi wrote in message ...
>On 2004-07-08, Tony <[email protected]> wrote:
>>
>> Donovan Rebbechi wrote in message ...
>>>On 2004-07-08, Tony <[email protected]> wrote:
>>>
>>>> I'm not relying on charmichael - and it may in fact be unproven in a
>>>> clinical sense - but it makes sense from the literature on weighlifting
>>>> muscle recruitment,
>>>
>>>What literature are you referring to ? Powerlifters include explosive
>>>repetitions at relatively light weights (high power output, low
resistance)
>>>and I can assure you that they're *not* doing it to increase type I fiber
>>>recruitment.
>>>
>>
>> Found several from googling this one is typical:
>> http://www.bodybuilding.com/fun/glen4.htm
>
>This isn't a journal article, and it doesn't support your claim (unless I'm
>misunderstanding what you're saying).
>
>In particular, the "slow twitch specific" training the article suggests
>involves using light weights *and* a fairly slow cadence (3 seconds down, 1
>pause, 2 up). The reason the article advocates this is that a faster
cadence
>(which requires high acceleration, which in turn requires greater force
>production) will result in more type II recruitment.
>
>Think about it this way -- we know sprinters have predominantly type II
fiber.
>But their body weight is ridiculously light compared to their strength. A
good
>weight-trained sprinter will probably be able to squat 2.5-3.5xbodyweight
or
>so. So sprinting is actually high power production, high cadence (240 or so
>compared to 180 or so for distance) low resistance exercise -- and it
>predominantly recruits type II fibers.
"The slower the fibre the lower the threshold for recruitment (the easier it
is to activate the fibre), as well as being more fatigue resistant. As you
move up the continuum the fibres recruitment threshold increases, but its
fatigue resistance decreases
"This plays a vital role in how muscle fibres are recruited. During muscle
contraction fibres are recruited in an orderly manner referred to as the
'size principal'.1 Basically the small slow fibres with their low
recruitment threshold are recruited first and as increasing force is
required the larger fast twitch fibres are recruited along the continuum.
"As can be seen slow fibres are recruited first, with fast fibres being
recruited when greater effort and loads are required."
The way I read this is that when a light force is required, the slower
fibres (type I first) are recruited because they have a low threshold for
recruitment. It's the force necessary not necessarily the speed. Don't
confuse slow fibres here with relative speed of contraction here. In the
case of a higher cadence the contraction may be somewhat faster but the
force required is less, and that's why the slow fibres can handle the force
necessary. As the force necessary increases with a low cadence, faster
fibres are needed more to meet the force demand. At some point the actual
speed of the contraction necessary may be important, but this does not seem
to be in the case of high-cadence cycling.
- Tony
>
>Cheers,
>--
>Donovan Rebbechi
>http://pegasus.rutgers.edu/~elflord/