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Running Training: Aerobic Profile

Article By: Jack Daniels

This article is a continuation from Part 1: Principals Of Training


Part 2:

Aerobic Profile.
The following discussion summarizes the importance Of V02max, (maximum oxygen consumption), running economy (VO2submax), and lactate threshold (threshold) for a distance runner.

V02Submax. Let's say we have a runner who has reached a "steady state" of exercise, by running for about six minutes at a sub-maximal speed (8:00 per mile pace, for example) and a bag of expired air is collected from this runner, during the final minute or two of this six-minute run The analysis of this runner's expired am will tell us what the aerobic (oxygen) demand of running at 8:00 pace is for this particular runner. Heart rate, also taken during the final minute or two of the run, and a small finger-stick blood sample (drawn immediately upon completion of the run) will provide information on the pulse rate and blood-lactate accumulation, associated with this velocity of running, for this particular individual.

If the same procedure is repeated several times at increasingly faster (but still sub-maximal) running velocities, then the V02, HR (heart rate) and BLa (blood lactate accumulation) responses can all be plotted against running speed. Figure 4 shows such data, which I have collected on one of the many athletes I have tested over the years. Notice that the V02 response is a relatively linear (straight line) one, as is HR. Blood-lactate accumulation, on the other hand, shows a different picture. Easier running speeds show little change in BLa, but as the speed of running reaches a more demanding intensity, there is a - dramatic increase in blood lactate. This lactate-response curve is typical of what any runner would show, with the exception that the better the runner, the faster would be the running pace at which the lactate-response curve would demonstrate the change from a flat to a rather steep slope. The intensity at which this b-transition from a gradual to a steep lactate curve takes place is referred to as this individuals lactate threshold intensity.

If the runner being tested completes three or four submax tests (at increasingly faster speeds, up to about I OK race pace or a little faster), and then performs a "max" test, the response picture becomes adequate for determining current training, and even competitive intensities of running.

V02Max.
The next test is one in which the runner starts running at the same pace as was used for the final submax test (about current 10 K race pace). This speed is held for two minutes on a treadmill (or for about 400 meters, if being run on a track). After this initial two minutes, a one percent grade is added to the treadmill each minute (or the pace is increased to 5K race pace in a track test). In a treadmill test, when the intensity of the ever-increasing treadmill grade forces the runner to not be able to continue, then the test is over. In the case of a track test, after two or three laps at 5K race pace, the runner completes a fu]M 400 meters at an au-out speed, after which the test is terminated.

In either case, expired air samples are continually collected, starting with about the third minute of the max test and ending when the runner stops. Heart rate is taken at the end of the test (or recorded during the final one-half minute of the test if using a monitor). The final blood sample (used to detect maximum lactate accumulation) is drawn two minutes after completion of the max test (when blood lactate reaches its peak).

Velocity at V02max.
By adding the highest V02 measured during the max test (this is VO2max) and the HRmax and BLamax data points to the subrmx data shown in Figure 4, we get Figure 5, what I refer to as a runner's "aerobic profile." V02max is placed on an extension of the economy curve (the line drawn through the previously-calculated V02submax data points), and this permits the determination of the velocity at which V02max would first be realized. This velocity is simply called VO2max (velocity at V02max) and is used to calculate a "VDOT" value, which, in turn, determines training paces and race potential VDOT will be clarified later.

Differences in Aerobic Profile. If the results of V02 tests performed on different individuals or groups of runners are plotted, as is done in Figure 6, then we see some interesting information become apparent.

Figure 6
compares three female distance runners, all of whom ran very similar times for 3000m, but with different aerobic profiles. Notice that runner A and C have similar V02max values, but runner C is much more economical (has a lower economy curve), but also a much lower V02max than runner A. Their similar vVO2maxes suggest that if both runners ran a 3K race at their respective V02maxes, they would finish in times of 9:06 for A and 9:08 for C, times which are within a few seconds of what they actually did run, which are also shown in Figure 6.

The Importance of V02Max.
By now it should have become apparent that the measurement of V02max, by itself, provides very little information in terms of discriminating between groups of good runners. As a result, when I hear that some runner was found to have a V02max of 90 ml/kg/min , I have one of two immediate reactions. First, the tests may have been poorly controlled (inaccurate reference gases used for the gas analyzers, faulty equipment used in measuring ventilatory gas volumes, leaky equipment, etc.). Second, if the tests were well controlled, why doesn't this runner outperform everyone else, hands down?

Assuming that this runner with the high V02max really does have an accurate assessment of his aerobic capacity, the most logical reason why he doesn't out perform everyone else is because his economy is poor. When a runner with a 70 V02max runs a 2:10 marathon and outperforms a 90 V02max runner, imagine how poor the latter's efficiency must be. And who is to say the 90-VO2max runner can improve efficiency (economy) any more than can the 70-max runner improve his V02max? Learning your actual V02max cm be useful for monitoring changes, in response to training, but learning your V02max, without supporting information concerning your economy can be misleading.

Changes in Aerobic Profile.
Keep in mind that V02max, economy and lactate accumulation all respond to training. Specific types of training should be used to optimize each of these components of performance. An important relationship between V02, RR, BLa and V02max should be pointed out here. The configuration of the economy curve (which plots V02 against . velocity) is such that a one-percent change in velocity is nearly also a one-percent change in V02. This results in an intensity of 70'D/o V02max being equal to 75% vVO2max&x and 88% V02max equal to 90% vV02Max. Both of these intensities are important and will be referred to in detail when I get into training.

The relationship between velocities and intensities are extremely useful; they signify that if vVO2max can be identified, there is no need for V02max or economy testing for the purpose of setting training intensities. Fortunately, current vVO2max can be very closely estimated from knowing the race performance capabilities of a runner-- You can use current race information to determine how hard to train. Furthermore, I believe this is a better way to do it than to rely on laboratory tests. Further, laboratory testing is simply not necessary for the masses of runners and coaches who should be using more concrete information to plan training intensities. After all, what is better than using how good you are as a measure of how fast you should train?

Part 3: Goals Of Training: Continue Here

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