Posted: December 22, 2004

Running:Improving Lactate Threshold

From Road Racing for Serious Runners by Peter Pfitzinger, Scott Douglas

Although lactate-threshold training is the most important type of training for distance runners, many runners don’t understand how to improve their lactate threshold. The best way to do so is simple - train at, or just slightly above, your lactate threshold. Although lactate-threshold training may seem like a form of speedwork, it’s more accurate to view it as a determinant of your endurance, the ability to maintain a pace for a prolonged distance. That’s why it’s appropriate to include it in this chapter on improving endurance, even though training to improve lactate threshold involves running significantly faster than on distance workouts.

LT workouts are of three basic types, all of which you run at the pace that coincides with your lactate threshold. The objective of these workouts is to run hard enough that lactate is just starting to accumulate in your blood. If you train at a lower intensity, there won’t be as great a stimulus to improve lactate-threshold pace. If you train faster than lactate-threshold pace, you’ll accumulate lactate rapidly, which won’t train your muscles to work hard without accumulating lactate. As we saw with VO2max training in chapter 2, training most effectively doesn’t necessarily mean training as hard as possible. Rather, as with training to improve VO2max, the more time that you spend at the proper intensity, the greater the training stimulus.

The training schedules in chapters 6 through 10 include the appropriate volume and frequency of LT workouts to improve performance at those racing distances. These schedules will provide a training stimulus to improve your lactate threshold while preventing overtraining. The three main types of LT workouts are tempo runs, LT intervals, and LT hills. In all cases, LT workouts should feel "comfortably hard." This means that you should feel as if you’re working at a pretty high level, but at a level you can sustain; if you were to increase your pace by 10 seconds or more per mile, you would have to slow within the next few minutes. If you’re sore and stiff the day after an LT workout, you’ve run too hard.

Tempo runs
The classic workout to improve your lactate threshold is the tempo run, a continuous run of 20 to 40 minutes at LT pace. An example of a tempo-run workout is an easy two-mile warm-up, four miles at 15K to half-marathon race pace, and a short cool-down jog. You can do this workout on the track or roads. At first, it’s a good idea to do tempo runs on the track or other accurately measured courses, so that you have a way of checking your pace. If you wear a heart monitor on an accurately measured course, you can use the heart rate you reached to determine the proper intensity for subsequent tempo runs. Whatever the method, after a few tempo runs you should have a feel for your LT pace. Studies have shown that most runners can reliably produce this pace once they have learned it. Low-key races of 5K to 10K make a great substitute for tempo runs. Just be careful not to get carried away and race all out.

LT intervals
Rather than doing a continuous tempo run, you can gain a similar benefit by breaking the tempo run into two to four segments. These workouts, also called "cruise intervals," were popularized by exercise physiologist and coach Jack Daniels. For example, three repetitions of 8 minutes each at LT pace, with a 3-minute jog between reps, will provide 24 minutes at LT pace. LT intervals are a good option if you tend to avoid tempo runs. The additional mental effort of tempo runs, however, may pay off when the going gets tough during a race.

LT hills
A great way to increase your lactate threshold is by running long hills. If you are fortunate (or unfortunate) enough to live in an area with a number of good-sized hills, you can do lactate-threshold workouts during a training loop by concentrating on working the hills. For example, suppose you have a 10-mile course that includes four half-mile-long hills and one mile-long hill. If you push the uphills so that you are running at LT intensity, you would accumulate 20 minutes or so at LTVO2 during your run.

Posted with permission from Human Kinetics Publishers, Inc.