Ragiarn—
Are you saying that working at AT levels helps increase the intensity at which one can work before lactate accumulates in the body and that AT training also conditions the body deal w/ lactate?
According to the authors of the book “Rowing Faster,” the way to increase the point at which lactate accumulate in the blood is through the use of “extensive endurance training,” sessions done at intensities well below AT.
Regarding lactate tolerance, Mike Caviston has called that a “fallacy.” Previously he wrote:
“The body deals with reduced pH, or neutralizes excess acid, with a combination of bicarbonate, phosphate, and protein chemical buffers (including hemoglobin). I know of no compelling scientific evidence to suggest that training has any effect on the body’s buffering systems. I have at hand a half dozen of the leading Exercise Physiology texts that all say the same thing. For example, from McArdle, Katch, and Katch: “It is tempting to speculate that anaerobic training has a positive effect on the body’s capacity for acid-base regulation, perhaps through the enhancement of chemical buffers or the alkaline reserve. However, it has never been shown that buffering capacity becomes enhanced through exercise training.”
I’m no expert. I'm just trying sort through what appear on the surface to be some contradictions. Thanx.
Tom
There are a couple of issues here.
First I agree with the statements made by Mike Caviston completely. He was addressing the issue of "so called lactic acid causing fatigue".
Lactic acid and lactate are not the same.
When lactic acid is produced it is quickly converted to lactate which is not an acid and therefore has no effect on the acid-base balance of the system.
In the process of breaking down glucose for energy there are two phases. The first phase is anaerobic which means it does not need oxygen to produce energy. The by product is pyruvic acid. If there is not enough oxygen the pyruvic acid is converted to lactic acid but just as quickly is converted into lactate.
Lactate is produced in abundance only when there is insufficient oxygen available to the working muscle. Normally in conditions in which there is adequate oxygen available to the muscle the breakdown of glucose yields pyruvic acid which then goes on to produce more energy in the krebs cycle.
During very short burst of work such as a short interval the lactate is produced but remains in the muscle and once the interval is finished working and oxygen is now more readily available the lactate is then converted back to pyruvic acid.
That is why you are breathing so hard after a short intense interval.. Your lungs are trying to keep up with the demands of those muscles which have accumulated all that lactate. Once your breathing returns to normal and the HR has returned to base line everything is restored, the muscle has converted the lactate to pyruvic acid ready to enter the krebs cycle and you can now proceed to do another high intensity interval.
Despite what you hear in the gyms lactate and lactic acid do not accumulate for very long in your muscles. And it does not cause your muscles to be stiff or sore nor do they cause fatigue. By the time you have finished your cool down row all the lactate should all be out of your system.
This issue of lactic acid build up in the muscle is another of the common pieces of misinformation I always hear from some of the so called fitness experts. Again no offense meant to the real fitness experts.
During prolonged high intensity intervals, or short intervals with inadequate rest between intervals, there is too much build up of lactate and the excess has to leave the muscles.
When there is an excess of lactate being produced by working muscles the excess leaves the muscle and enters the blood stream where it is taken up by other working muscles for their use or by the liver and re-constituted into glucose.
The type I muscle fibers (the fibers which are developed in doing lower intensity endurance work) readily accept lactate and in the presence of oxygen lactate is converted back to pyruvic and then goes on to the Krebs cycle to produce more energy.
While the lower intensity endurance work enhances the type I muscle fibers and therefore the ability to dispose of excess Lactate, you need to do the AT work in order to produce the Lactate so that muscles and liver are stimulated to produce the mechanims for using the Lactate.
The lactate threshold or OBLA- is the point at which lactate begins to accumulate in the blood stream. There is always a certain amount of lactate present (2 mmol) but once you reach a certain level of work the levels begin to rise. With proper training you will develop the mechanisms of disposing of this lactate more quickly thus maintaining a modest level. Remember LT work is also endurance work but at a high intensity level.
A good program will have a mix of workouts to stimulate each of the various metabolic pathways and induce various adaptations. Mike Caviston's Wolverine program is an excellent example. His level 4 and 3 workouts are are done at below LT zone. Level 2 are mostly LT workouts and Level 1 are a mixture of AT and LT/AT workouts.
This my summary of his workouts which I found in his posts:
Level 1 workouts Intensity: 95-105% Level 1, SR 30-36.
total number of meters in one workout should add up to about 4000
8 x 500m
4 x 1K
4K Pyramid (250m/500m/750m/1K/750m/500m/250m)
Level 2 workouts Intensity: ~ 90-95% 2K ) SR 26-32 PR pace * 1.08.
5 x 1500m;
4 x 2K (recov 1500 m)
3K/2.5K/2K
Level 3 Intensity: 85-90% of 2K velocity. SR 24-28;
Continuous 12K
2 x 6K (with 7-8’ recovery between pieces)
15 x 3’ (with 1’ recovery between pieces)
Level 4 Intensity: ~ 80-90% of 2K.
40-70’ of continuous effort. Other variations include
2 x 40’ (with 6-7’ recovery between pieces) and
4 x 10’ at a proportionately greater intensity (with recovery intervals of 3)
This post is too short to do this topic justice so if there are further clarifications needed I will try to make them.
