THE LACTATE DEBATE

Rushall, B. S. (1991). The lactate debate - one more time. Journal of the Australian Swim Coaches' Association, 8(3), 8-12.

During the 1991 Annual ASCA Conference much debate was devoted to lactate testing in swimming. Dr. Alan Roberts accurately described the status of knowledge about lactate measurement procedures although that might have been lost in the "hysteria" generated by persons vitally involved in this matter. He correctly pointed out that there are a variety of methods for measuring and interpreting lactate recordings. That scientists cannot agree on one best method and interpretation should indicate something to the coach -- BEWARE!

To those of us who traveled from afar to participate in the Conference this program event, its focus, and what was claimed were observed with both disappointment and amazement.

There is an extensive body of knowledge concerning lactate testing in many sports and much practical assessment of its value. It has been considered and placed in perspective in relation to all other factors that affect elite athlete performance. It is worthwhile to consider what is known and being done with lactate measures in sport so that Australian swimming will not follow a dubious path of decision making.

Who Do You Listen To?

Lactate testing is not a new procedure. It is a research variable that "has run its course" in academe. It does yield some information that is important for understanding performance. It is still used in sport physiology research but seems to be losing favor for use in applied settings. Australia is not the repository of "new" evidence or insights into its value in sports. Australian swimming should heed what is known world-wide. There is a generally accepted knowledge concerning the lactate--performance relationship. Those understandings and verified uses are far different to what is promoted in Australian swimming.

If what is being done is actually wrong (a substantial case could be made to support this) then Australian swimmers are being placed at a disadvantage in relation to the rest of the world.

What Do Lactate Measures Show?

Lactates are a partial measure of the amount of anaerobic work that is performed in a task. In sports where localized fatigue is prevalent, it is higher in some parts of the body than in others. When measures are taken in local-fatigue activities such as swimming, those measures are dubious.

Lactate measures are affected by many factors. Some of the more significant modifiers are: i) diet; ii) state of long- or short-term fatigue; iii) movement efficiency or inefficiency; iv) mental state; v) task perceptions; and vi) environmental modifying factors (e.g., altitude, water temperature).

The existence of these modifying factors will decrease the value of the information that is generated by lactate measures. For accuracy, the control of these factors is very important and is one of the reasons why lactate measures remain popular in research laboratories (where influential variables can be controlled). However, a lack of control is also one of the reasons why they are receiving less emphasis in sport settings. Lactate measures are of greater use to scientists than coaches.

In the best sporting circumstances, lactate measures are relatively gross measures of performance. They may be sensitive enough to measure obvious improvements in early exercise adaptation states but are not sensitive for assessing the subtle changes which occur as the "athletic state" is nearing its maximum value. It is only appropriate to use lactates to measure performance capability changes in the early stages of exercise adaptation ("change" training). The fitter an athlete becomes, the less valuable are lactate measures for assessing trained states.

What Lactates Do Not Show

  1. Lactate measures do not reflect whether one or more performances evidence a desirable trained state (too many factors distort the picture).
  2. They are not of sufficient sensitivity to be used as a measure of highly trained states, maintenance training, and in particular for Australians, tapering responses.
  3. They do not reflect a significant portion of a swimmer's response. In the past, estimates of the ratio of aerobic to anaerobic work in swimming events have been significantly in error. There is even more aerobic work in all swimming races than has previously been thought. This means that measures of anaerobic work are less important in the global energy picture for swimming. However, anaerobic work is still an important aspect of swimming particularly when the difference between winning or losing can be minutely small.
  4. Lactate measures do not provide sufficient evidence to make an alteration in an athlete's training program when they are the sole index used.
  5. Lactates cannot and should not be used to predict a swimmer's response. They concern such a small portion of an athlete's total response that attempts to predict or diagnose performance from its values would introduce more error than accuracy into any decision.
  6. A lactate measure after a performance gives no information about when it was accumulated in the performance. Thus, knowing the lactate level yields nothing about how it was formed.
  7. "A swimmer's ability to produce high lactate values tells little about his or her anaerobic capacity or rate of anaerobic energy use" (Troup, 1991, p. 14).
  8. Roth (1991), when discussing lactate testing in rowing, concluded "Lactic acid concentration measured after a race [performance] gives no information about when it appeared in the race [performance]." Thus, knowing a lactate level tells you nothing about how it was formed in a performance.

What Is the Use of Lactate Measures in Sport?

  1. It is of interest to sport scientists as one portion of work assessment. It is usually used in concert with other measures of performance response in scientific work.
  2. In sport practice, it is a periodic measure of early stages of the stress adaptation response.
  3. Where investments have been made in personnel and equipment and the continued use of such resources has to be justified, it can be touted as a "bell weather" measure of an altered state of training in an athlete, that is, when measures change when compared to previous ones on a standard controlled task, it indicates "something" is different. That difference is not necessarily due to the fitness of the athlete.
  4. Frequent lactate testing is of little value. Once per 14 days seems to be an acceptable interval between assessments.
  5. In practical situations, it could be one of a variety of objective measures which assess the dimensions of an athlete's trained state, skill efficiency, and mental control.
  6. Troup (1990) asserted that lactate testing is a good indicator of how one responds to an overload but is not good for prescribing training paces specific to work categories. That is because lactate removal rates vary between athletes and do not depend on training intensities. Lactate values must be used with caution and testing should be limited to simply describing how muscles adapt to different workloads and whether an overall training adaptation is taking place.

Lactate accumulation is duration dependent because some longer swimming races (200 and 400 m) produce more lactate than shorter ones. The need for a strong buffer capacity is highest for 200 m events. This suggests that lactate tolerance training (AN-1) is very important for that distance.

What Does One Do if Significant Investments Have Been Made in Equipment and Personnel for Lactate Testing?

  1. Do what other nations have done; i) quietly reduce testing, and ii) only use results in concert with other measures of performance factors.
  2. Embark on a more comprehensive program of ongoing performer analysis that will yield valid and reliable information that has predictive or diagnostic value.

How Then Can One Tell if Swimmers Are Improving?

  1. Measurement is the only answer.
  2. The best and most valid measure is swimming performance itself. If swimmers are swimming faster they are improving.
  3. How can one tell if swimmers are improving when they are tired? Unfortunately there are no measures that will tell if an athlete is improving when he/she is fatigued. The procedure of deliberately and continually fatiguing athletes is an out-of-date philosophy that is not substantiated by contemporary sport science knowledge or successful athlete training practices (see Bompa, 1986, and Rushall & Pyke, 1990).

A Concern

The principal concern of this writer is that Australian swimming has employed a simple test that is of limited value for making coaching decisions, particularly with regard to training and tapering stimuli. It is used in a manner that should result in more erroneous than sound decisions.

There are better and more comprehensive measures of performance. Some examples are listed below.

  1. Energy economy for varying standards of swimming speed (Troup, 1990). As fitness and/or technique improves the graphed relationship curve shifts to the right.
  2. Perceived exertion for varying standards of swimming speed and for a set task. The exertion estimate is graphed against the speeds and should shift to the right as training improves due to either or both fitness and technique factors.
  3. Subjective stress symptoms indicate the capacity to train and have been used successfully in a number of sports including swimming (Rushall, 1990).
  4. Stroking efficiency is field tested by counting the number of strokes to cover a certain distance in a set time or plotted against time for a given distance. As technique improves the graphed curve should shift to the right.
  5. Any gross physiological measure such as recovery heart rate for the 10 to 20 second interval upon completion of a task; the summation of 10 second heart rate counts for the 10-20, 40-50, and 70-80 second intervals after a task; and summed respiration rates between the 10-20 and 40-50 second intervals after a set task; all graphed against performance time for the selected task.

These measures are not new. They are alternative variables that are supposed to reflect the training and technique development response. With improvement there should be a movement in a standard plot curve and with degradation the curve should recede. The consideration of several of these measures will serve to cross-validate each interpretation. They are as meaningful as lactate measures however, they are not couched in the "dazzle" that surrounds the procedure of drawing blood and using a high-tech piece of equipment. Multiple measures can be used to direct the content of swimming training programs more constructively and inclusively. They should be employed instead of or at least in concert with lactate testing.

Are Lactates Useful?

Despite what has been stated above, lactate measures have some use. In the last 10 years they have been used to assess the degree of recovery from training stress. For example, a swimmer is set the task of completing eight 200-meter repetitions while holding 800 m race pace on a 1:2 work:recovery ratio. If the swimmer's performance deteriorates after the sixth repetition, then a lactate measure is taken to indicate if recovery is being adequately promoted in the set. If the readings are still high, then further rest between repetitions is warranted and the set is modified accordingly for the remaining repetitions so that performance quality is maintained.

The above example demonstrates a difference in lactate use philosophy. Australian, American, and Canadian coaches use lactate measures to indicate how hard swimmers have worked. On the other hand, progressive European coaches use the measures to indicate whether the swimmers have recovered sufficiently between repetitions to maintain the integrity of performance quality in the training set. The European "recovery" approach produces more quality training in athletes than does the Australian "work" orientation. The latter produces more maladaptive work and excessive fatigue than is necessary in the sporting experience.

The lesson from the above comparison is that lactate measures are better used to indicate if sufficient recovery has occurred after performance decrements or fatigue have been evidenced as opposed to assessing work.

So What Does An Australian Swimming Coach Do?

There are a number of options for coaches to proceed with testing that will provide them with information about a swimmers' training.

  1. Set up a series of alternate testing methods that will complement each other.
  2. The testing series should involve analyses of physiological, biomechanical, and psychological states.
  3. Allow coaches to test the use of these various measures.
  4. Allow coaches to select those tests that best assist them in their coaching decisions.
  5. Verify the selection of testing methods and/or coach use by assessing the successes and failures of swimmers to perform their best on particular designated occasions. Do not be fooled by only considering successes (which might have occurred despite the measurement methods and coaching).

It is hoped this paper clarifies some of the confusion and misconceptions that surround the lactate testing of swimmers.

References

  1. Bompa, T. O. (1986). Theory and methodology of training. Dubuque, IA: Kendall/Hunt.
  2. Roth, W. (1991). Physiological-biomechanical aspects of the load development and force implementation in rowing. FISA Coach, 2(4), 1-9.
  3. Rushall, B. S. (1990). A tool for measuring stress tolerance in elite athletes. Journal of Applied Sport Psychology, 2, 51-66.
  4. Rushall, B. S., & Pyke, F. S. (1990). Training for sports and fitness. Melbourne: Macmillan Australia.
  5. Troup, J. P. (1990). International Center for Aquatic Research Annual - Studies by the International Center for Aquatic Research 1989-90. Colorado Springs, CO: United States Swimming Press.
  6. Troup, J. P. (1991). International Center for Aquatic Research Annual - Studies by the International Center for Aquatic Research 1990-91. Colorado Springs, CO: United States Swimming Press.

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