Lactate SCOUT - Basics
Sufficient energy is necessary for effective muscle activity. When the body is at rest or at a low activity level, it regenerates itself primarily through aerobic metabolism. At higher muscular activity levels, energy is supplied increasingly without the use of oxygen, through anaerobic metabolism:
Lactate is produced as a by-product of anaerobic metabolism (glycolysis).

Effort levels can be increased as long as the lactate produced is eliminated as quickly as it is produced (steady state). However, at some point, depending on the conditioning of the individual, the amount of lactate in the muscles and blood will begin to increase: More lactate will be produced than can be cleared.

Sports medicine experts are convinced that endurance training is most effective when it is done near the maximum lactate steady state (maxlass), because there's the best stimulation of the body with all the desired effects like fat-burning, higher aerobic capacity and improved performance. Conversely, in overexertion and or unsuitable training, which is often observed with amateur athletes, high lactate values, above this anaerobic threshold occur and may cause several health risks.

Analyzed in a graded exercise test (step test) with several lactate measurements, the shape and direction of the lactate curve determines the best training paces. Each individual's maxlass can be found easily using modern lactate analyzers as Lactate SCOUT.
You can download a scientific comment of the biochemical background here (written in German):
 Biochemischer Hintergrund

To get meaningful results by a step test, ensure to be in regular condition: Don't train too much the previous day and have no extraordinary diet or meals before! After a short "warm up" without real strain, take the first value. Depending on your condition, the reading will be between 0.8-2.0 mmol/l.

Now choose the first exercise step, such as an easy running speed for 5-6 minutes. You can use the stopwatch "clc" of the Lactate Scout to control your velocity. Take now the second value and continue:

Increasing your speed step by step (reducing your lap time), your lactate values are growing: At first, the increase will be moderate, but after the third, fourth or fifth step, the lactate value will start to rise quickly.

Record the estimated lactate threshold speed (a little bit below the last speed, as the value was increasing so much) for your future training. Finishing your actual training, it's recommended to make a "cooling down" run without any strain and to take a last measurement after 5 minutes again. This value shows how fast your body can eliminate the produced lactate.

In some weeks repeat the test again: When you've trained close to your maxlass speed, you will see the effect in a higher aerobic capacity and better condition: Good luck!