Guest guest Posted September 7, 2004 Report Share Posted September 7, 2004 Can you provide any references supporting your contention that fast twitch muscle is converted to slow twitch? I haven't done any reading as of late on the subject but what I have read did not show any changes in realtive percentage of fast twitch vs slow twitch with specific training protocols but this % is genetically set. Hypertrophy of a particular fiber type may occur in response to a particular stimulus but I would be interested in any references showing a change in actual relative percentage composition of fiber types. Thanks. --- In , " john roberts " <johnhrob@n...> wrote: > Endurance training has the bad effect of converting fast twitch to slow > twitch, but the only way to build capacity is by endurance training. Perhaps > another reason why world class runners specialize. > > I try to keep what little fast twitch I have hanging around by playing > basketball, although these days my lack of quickness and diminished mass > leaves only gray matter and a decent outside shot as useful tools. > > I found it amusing that last weekend it was the 30 something kids who were > complaining about running full court. :-) > > FWIW I think the big drug Co.s developed some growth hormone related > medicines in search of the elusive " youth " pills but it didn't work as > expected. Apparently aging is a multi-faceted thing. Hard to attack with a > single vector mechanism. CR is the best shot for at least slowing it down... > maybe stem cell for rework and repair. > > JR > > -----Original Message----- > From: aequalsz [mailto:aequalsz@y...] > Sent: Saturday, September 04, 2004 3:48 PM > > Subject: [ ] Re: Walk, Don't Run > > > > According to, > > http://www.theharrier.com/B.html > > " Avoiding serious injury and the resulting training breaks, said the > University of Colorado's Mazzeo, professor of kinesiology and > applied physiology, has enabled to continue producing > sufficient human growth hormone to stimulate muscle mass and the high > percentage of fast-twitch muscle fiber needed in sprinting. " > > > On a personal note, I try to keep my HGH supply high by ending my > treadmill runs with a 150 yard " sprint " . Read somewhere > that high intensity exercise promotes the production of HGH but I > don't know how effectively it does this. Anyway the treadmill > " sprinting " at least tends to break up the monotony. > > Aequalsz Quote Link to comment Share on other sites More sharing options...
Guest guest Posted September 7, 2004 Report Share Posted September 7, 2004 comments below -----Original Message----- From: freebird5005 [mailto:freebird5005@...] Sent: Tuesday, September 07, 2004 7:12 AM Subject: [ ] Re: Walk, don't sit Can you provide any references supporting your contention that fast twitch muscle is converted to slow twitch? I haven't done any reading as of late on the subject but what I have read did not show any changes in realtive percentage of fast twitch vs slow twitch with specific training protocols but this % is genetically set. Hypertrophy of a particular fiber type may occur in response to a particular stimulus but I would be interested in any references showing a change in actual relative percentage composition of fiber types. Thanks. ========= --- In , " john roberts " <johnhrob@n...> wrote: > Endurance training has the bad effect of converting fast twitch to slow > twitch, but the only way to build capacity is by endurance training. Perhaps > another reason why world class runners specialize. > =================== http://sportsmedicine.about.com/cs/exercisephysiology/a/aa080901a.htm **excerpt*** Can you change your muscle fiber type by training? This is a hard question to answer because good studies are just now being conducted (3). Currently, there is limited evidence to show that human skeletal muscle switches fiber types from " fast " to " slow " due to training (4). Researchers have demonstrated a fast-to-slow fiber transformation in animal skeletal muscle, and the human studies are showing similar outcomes. There is decent evidence that pure fast (Type IIb) fibers can transition to " hybrid " (Type IIa) fibers with chronic endurance training. (3) Thayer R, J, Noble EG, AW. A decade of aerobic endurance training: histological evidence for fibre type transformation. J Sports Med Phys Fitness. 2000 Dec;40(4). ================= OK, you got me... I was speaking purely from recollection of articles I read when I first started jogging a few decades ago. I am sure there are huge genetic factors in our initial balance of fast vs, slow twitch, but it seems logical (to me) that if we preferentially train one type the other will be diminished by normal protein turnover. The above citation seem to support my suggestion but I haven't read the reference article. JR Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You are posting as a guest. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.