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Ascending or Descending Sets?

July 19, 2005 01:31 PM

So, which is the best way to hit the FT and ST fibers? Dr. Hatfield recommends that you start heavy and end light over your sets. The theory is that the FT fibers fatigue faster and then you move on to the ST fibers with lighter weight and more reps. These used to be called drop sets.

Others suggest that you use isometric contraction against elastic cords (see my earlier post) to tire the ST and then recruit FT fibers as the exertion is prolonged.

There is no doubt each of these approaches works. I use both techniques. So, why do I have a preferred technique?

Because I want as much FT fiber as I can get and the others put a bit more emphasis on the ST fiber. The FT fibers are energetically expensive, so I stay lean, and they are the most powerful and I like power. They also are free fatty acid metabolizers supreme.

My ascending sets work on the principle that the fiber types have different thresholds before they will contract. By starting light with higher reps, I fatigue the ST fibers. The immediately following set is heavier and fewer reps. This intensity moves into the threshold for firing the glycolitic FT fibers and they also begin to take over for the fatigued ST fibers.

The next set is heavy and it is possible to do only a few reps. By now the ST fibers are exhausted and you are into both FTa and FTx fibers, the latter having the highest threshold for firing.

Doing the exercise this way maximizes the lactic acid generated because there is no rest or easing of the load one the FT fibers that create it. In the descending exercise, the ST fibers take over the load and no longer produce lactic acid.

Why do I want lactic acid? First, it maximizes growth hormone (GH) release, which is good. Second, the acid environment bathing the muscle expresses genes that produce the FTx muscle proteins actin and heavy chain myosin.

Sattar seems to have it right. Why stick to just one form of exercise? Adaptation is very specific so it pays to incorporate some variety in your work outs. Use all three techniques. But, the kind of variety we seek should be somewhat rhythmical so it has a natural feel to it. Sattar has the idea when he uses the rhythm of the hunt to alter his work. This has been my model for many years and it is captured by the power laws of my system.

Abrupt changes are good, but they should be a bit rare and brief. Most changes should be small. This is the form of randomness in the Evolutionary Fitness model that is captured by the power law; a few really large changes of brief duration, but many smaller ones, with no characteristic size of the change or duration.

· Evolutionary Fitness

Comments

Posted by: Flower Online [TypeKey Profile Page] at September 12, 2006 4:29 AM

I think every smart trainer targets the fast twitch, however, the preferred way (I’m not saying it’s the best) is to just lift heavy weights. The theory is that the ST muscles are recruited first, then the FTa then FTx. If the weight is light only ST muscles are recruited. Art’s idea is to pre-fatigue the ST muscles so they are already out of the equation and the body must recruit FT. The medium range fatigues the FTa leaving only the FTx. With all this talk about fiber types, I wonder how these different training methods affect the nervous system since strength and speed have a significant neural component.

Posted by: Woody at July 20, 2005 8:50 AM

The entry was June 5 and the topic was Athletic Quickness.

Posted by: Arthur De Vany at July 19, 2005 4:12 PM

Art,
What do you think of using a fixed weight and then banging out sets in rapid fashion, which ultimately results in fewer reps each set? For instance, one day per week I engage in 8 sets of dips and 8 sets of pullups with 10 second rest bewteen sets. Dip x max, rest 10 seconds, pullup x max rest 10 seconds, dip x max, etc. By the eighth set I am lucky to get 3 reps in. I believe that this makes deep inroads into my FT fibers and keeps me from wasting time between sets with varying loads. It's sort of like a Tabata style upper body workout.

Posted by: Kevin at July 19, 2005 2:17 PM

I can't seem to find by searching the previous post on using elastic cords. How previous was it?

Posted by: Fugate at July 19, 2005 2:15 PM

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