Lactate Physiology and Sports Training

Part 3 -Reasons for Lactate Testing

So, why measure lactate? Basically there are five very important reasons to measure lactate for an athlete. Some coaches have suggested a sixth. These are:

1. Measuring lactate levels provides the best measure of the stress exerted on the muscles during a workout.

When a coach specifies the intensity or speed of a workout, the coach should know the lactate that this intensity or speed will generate. Otherwise they are guessing what the workout will accomplish.

When an athlete produces lactate in a certain muscle group, it means that some of those muscles can no longer process all the needed fuel aerobically. The amount of lactate produced is an indication of how limited the aerobic energy system is in the exercised muscles. Exceeding the current limit of aerobic metabolism is what will cause the muscles to adapt and eventually process more fuel aerobically. Up to a point, the more stress placed on a muscle's metabolism, the more adaptation will take place. It will never be possible to process all fuel aerobically, but most athletic events depend on high levels of aerobic processing capacity. Eventually the athlete will start to see lower lactate levels at every sub maximal effort as the muscles process more energy aerobically.

Because the amount of lactate generated at a specific effort shows the limits of aerobic metabolism it is the best measure of the stress a specific exercise program is generating. When a coach knows the lactate profile for each athlete (they will all be different), the coach can specify individual training programs. Athletes will all respond differently to the training programs, too. Without lactate tests there is a lot of guessing. Good coaches are excellent guessers but even they may not be sure about every athlete.

Until recently, a laboratory was the only place you could measure lactate. So coaches and athletes have relied on imprecise measures of metabolic stress such as heart rates, perceived effort or distance tests. However, with the introduction of a portable lactate device it is possible for coaches to measure lactate anywhere, in the gym, at the pool, on the track, on the road, on the water, at the rink, on the ski trails and slopes and even at the top of a mountain.

Other methods of measuring stress are either imprecise or very impractical. When using heart rates to estimate the stress put on an athlete's muscles, a coach is substituting this measurement for lactate levels. But this is a hit-or-miss proposition. The stress in the muscles associated with a particular heart rate or percent of maximum heart rate can vary substantially from athlete to athlete. So without a link to lactate levels, heart rates can be very imprecise.(See section on Heart Rates and Lactate.) Nearly every article or book on the use of heart rate training discusses the importance of measuring lactate but says that it is impractical for the typical athlete because of cost or the unavailability of lactate testing equipment. However, given that there is now a 4 oz lactate analyzer that is quick and easy to use, can be taken just about anywhere and provides laboratory accuracy, it is difficult to say that measuring lactate is impractical6. When calibrated by occasional lactate testing, heart rates can be a very useful indicator of the intensity of a workout. But for some situations heart rates and perceived effort will always be very poor measures and are rarely a good surrogate for lactate testing. Neither will tell the coach how well an athlete is clearing lactate from his or her system. And above the lactate threshold heart rates are very constant and are not an indicator of what is happening in the muscles.

Another method often used to measure fitness or intensity of training is oxygen consumption (VO2). While it is desirable to have very high aerobic capacity, it is important to emphasize here that a large percentage of aerobic training has little to do with increasing the ability of the athlete to provide more oxygen to the muscles. Very often there is plenty of oxygen available to the athlete's muscle cells. Factors other than lack of oxygen limit the aerobic process. One of the most important limitations of aerobic metabolism is the lack of sufficient enzymes to facilitate the aerobic process. Another important factor is that the parts of muscle cells called mitochondria, which are necessary for the aerobic process, may not be dense enough to produce all the energy that is required. Both enzymes and mitochondria will increase with training of the specific muscles. Hence an emphasis on improving the body's ability to process oxygen may provide only limited performance benefits if the specific muscles used in competition are not also being trained. While the ability to process large amounts of oxygen is very important especially during competition, the muscles involved in the exercise must be able to utilize the oxygen.

2. Measuring lactate is the best way to find the lactate threshold (LT).

We have pointed out that the lactate threshold is an important marker for athletic training. Exercise at this effort level is thought to generate the most stress possible during a workout. However, unless a coach knows the LT of each athlete they are just guessing how best to train them. Several surrogate tests have been developed because lactate testing was not readily available until recently, but none is as accurate as actual lactate measurement. Athletes may go through several different types of protocols to estimate the threshold and then not be sure if the right effort has been chosen.

One coach said that after a year of working with an athlete, he could estimate the threshold to within a couple of beats using a heart rate monitor. A exercise physiologist listening to the coach describe the series of tests his athletes went through said:

Why don't you just measure it? It won't take a year or a week. It can be done in an hour and then verified in a half hour during a scheduled workout. When it is over you will know a lot more than what the heart rate monitor will tell you by itself.

3. Measuring maximum lactate production is an excellent and easy way to assess the anaerobic system.

Speed requires that muscles produce energy as quickly as possible. Thus, at high speeds, athletes produce large amounts of lactate very quickly. The level of lactate in the blood is one of the best measures of how fast the muscles are producing energy and how fast the athlete can go (the higher the lactate the better). As an athlete gets nearer to a major competition, the anaerobic system should be trained more intensely so that the athlete is ready for the important race.

While many athletes spend a lot of their training trying to limit production of lactate and shuttle it quickly from one muscle to another, they also train to produce as much lactate as possible at race time. So for peak performance athletes train their bodies to simultaneously produce large amounts of lactate in one energy system and limit it in another. We call this the Lactate Training Paradox.

There are two caveats that go with training the anaerobic system and its measurement. The first is that too much training to produce high lactates could negatively affect the training of other energy systems, especially the aerobic system. The second thing a coach should be aware of is that it is not possible to compare one athlete to another using this measurement. Because one athlete has higher levels of blood lactate than another after a maximal effort does not mean that the athlete with the higher blood lactate readings will produce a faster time or a greater anaerobic effort. But an athlete's highest max lactate is often prduced by a personal best time.

4. Measuring lactate is necessary because too much lactate in the muscles can cause muscle damage.

We have just pointed out that generating lactate is essential for adaptation. Also we have discussed why generating high lactate levels in a competition is essential for a good performance. However, producing too much lactate too often can be harmful. Frequent production of high lactate can cause muscle damage and impair performance, sometimes for extended periods of time. Thus a coach should be aware of how often the athlete is entering the danger zones of high lactate and acid production. As mentioned above, heart rates and perceived effort are poor indicators of this type of stress.

Every athlete has felt the pain and the inability to use muscles normally at high levels of intensity. Current thinking of sports scientists indicates that it is not the lactate itself that produces the pain. They believe that it is the acidic condition produced by hydrogen ions when the lactate is created that is the cause of the problem. However, by controlling the lactate in the muscles an athlete can control this acidic condition. About 85% of the hydrogen ions produced in the muscle during exercise are produced with the lactate and most are cleared with the lactate. This leads us to the fifth reason for measuring lactate.

5. Measuring lactate allows a coach to assess how well an athlete is clearing lactate from the fast twitch muscles and using it elsewhere.

We will discuss this important aspect of training several times. It seems that the ability to clear lactate from the muscles where it is produced is one of the important effects of training for nearly every athlete. In competition, if athletes are able to clear lactate quickly, then they will be able to utilize the fast twitch muscles for a longer time before high acid levels shut them down. During workouts, if athletes can clear lactate from the muscles quickly, they will be able to repeat high intensity sets or routines more often. Coaches should be aware of how long it takes an athlete to clear lactate and what level of recovery effort speeds this clearance.

If a coach observes an unfavorable change in clearance patterns, it may indicate either a potential problem with the athlete or the training. In either case the coach will know that something has to be done to reverse the unfavorable trend.

6. Measuring lactate encourages the athlete's interest in his or her own training program.

Several coaches have told us that after they started measuring lactate, many of their athletes became much more interested in doing their workouts. They were very interested in what the test results might be telling the coach. The coaches said that both they and their athletes started to understand more clearly the factors affecting the athlete's performance.

One last question: Who should use lactate testing?

This question provokes a lot of strong reactions. We are selling lactate analyzers so we are suspect. However, we will give you our answer anyway. We believe that any athlete who is physically and emotionally mature and is serious about training can benefit from lactate testing. Notice we did not mention anything about elite. We have witnessed several athletes who are very serious about their sport and want to do the best they can. They would be thrilled to be a contributor on a Division III collegiate athletic team or qualify for the Ironman championship. They are far from elite but are just as serious about their sport as those going to Olympic trials. They will benefit just as much from lactate testing as the Olympic finalist. They may finish 3 hours behind the winner at the Ironman but they are ecstatic about their performance. If someone is going to put in the long and arduous hours to train for an event, they should make the most of those hours.

Lactate tests require that the coach be very conscientious in conducting the test. Thus, lactate testing should only be done in carefully controlled situations. This doesn't mean that the cyclist cannot take a lactate test while on the road. It just means that every test should follow proper handling procedures for accuracy as well as sanitary reasons.

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A Fisiologia do Lactato e o Treinamento Esportivo

A Análise do Lactato