The Value of Lactate Threshold (LT) Training

Although the priority for distance runners is to maximize weekly mileage and their long run in order to improve performance, the importance of “lactate threshold (LT)” training should not be overlooked. LT training has been given a variety of names such as tempo running, anaerobic threshold (AT) running, lactate threshold (LT) running, and cruise intervals, to name a few. Lactate threshold training may be the most accurate name, since it involves lactate, a byproduct of carbohydrate metabolism. Lactate is produced in your body all of the time, when sleeping, resting, and exercising. Most of the time, the rate of lactate production is less than the rate of lactate clearance, allowing you to continue for long periods of time. However, when exercising above a certain intensity, the rate of lactate production exceeds the rate of clearance and the lactate begins to accumulate in your blood. This is your lactate threshold. In running terms, if you exercise at an intensity above your lactate threshold, you will slow dramatically! And there is no doubt about it, your lactate threshold is the most important factor in determining distance race performance.

Fortunately, we can train our bodies to produce less lactate at specific exercise intensities, as well as increase the clearance rate and tolerate higher levels of blood lactate. When this happens, we are able to run at a higher percent of our VO2max and max heart rate before the accumulation of lactate, allowing us to increase our running pace. A beginning runner may have a lactate threshold at 75% of her maximum heart rate, which will limit her ability to run faster paces in a distance race. After appropriate LT training, her threshold may improve to as much as 80 to 90% of heart rate max, allowing her to achieve a much faster pace before the accumulation of lactate.

There are a variety of training methods. We can perform 20 to 40 minute continuous “Tempo” runs at your 10 mile to half marathon pace or run 30 to 40 seconds slower than your 5 km pace/10 to 15 seconds slower than your 10 km pace. Pace is important! Train too slow and you will not get a training effect. Train too fast and you will not be able to run the necessary miles (time) needed to make an impact. Another method made famous by world class coach and physiologist, Jack Daniels, is performing cruise intervals. This is a tempo run chopped into segments or intervals with a short recovery jog between each. Cruise intervals of 3 to 6 x 1 mile with a 1-2 minute jog between each, 3 to 4 x 1 1/2 miles with a 2-3 minute jog, or 2 to 3 x 2 miles with a 3-5 minute jog are examples. Pace is the same as your tempo run. The lactate threshold (LT) workout can be performed 1 day per week in your training and should be a big part in everyone’s training cycle.