About Threshold Training

Legendary running coach Jack Daniels provides an inside look at the importance of t-pace.

Threshold, or T-pace, running is one of the most productive types of training that distance runners can do. Training at threshold pace helps runners avoid overtraining and yields more satisfying workouts and better consistency.

The two types of threshold training that I discuss in Daniels’ Running Formula are tempo runs and cruise intervals. Tempo runs—steady, moderately prolonged runs—have been around for some time, but runners and coaches define them differently. Cruise intervals are a series of repeated runs with a brief recovery between runs. In my book, I address the differences and similarities between tempo and cruise-interval workouts. Here, I’ll stick to tempo runs, including new information on extended tempo runs

Some runners and coaches use tempo runs for the broader purpose of just going for a fairly prolonged, steady, solid run—often, more for the psychological benefits (which can be considerable) than the physiological. The physiological benefit of running threshold is to improve endurance: the ability to endure a greater and greater intensity of effort for a longer and longer period of time. You might perform some (longer) tempo runs at an intensity slightly below threshold intensity, which offers a good opportunity to boost psychological endurance. Longer tempo runs that begin in the less intense area of the zone and progress to the higher end of the zone are accomplishing both the benefits of a longer tempo run and the benefits of true T-pace running.

Establishing threshold pace

The proper pace for T-pace running is about 83 to 88 percent of VO2 Max, or 88 to 92 percent of vVO2 Max or maximum heart rate.

You can establish your proper pace for threshold running fairly closely by running at a velocity that produces an elevated yet steady state of blood lactate accumulation. This pace is a little faster than a pace that you could maintain for two or more hours (marathon pace for most people) but slower than the pace you could maintain for 30 minutes (10K race pace for better runners). This pace is easy to discern because at the latter pace blood lactate continues to rise over the course of the run (that is, there’s not a steady state of blood lactate accumulation). Also, at the former pace, blood lactate slowly drops after an initial rise or after any elevated lactate resulting from race surges (also not a steady state of blood lactate accumulation).

Most runners can figure that their threshold pace is equal to a pace they could race at for 50 to 60 minutes. In fact, for slower runners, threshold pace might actually be 10K race pace because they are taking nearly an hour to “race” this distance. Intensity of effort, not necessarily distance of running or racing, is what determines the degree of stress being put on the body’s systems.

Remember that the purpose of the workout is to stress lactate-clearance capability, not to overstress that capability. I refer to threshold training as “comfortably hard” running. It shouldn’t feel “hard,” which is the pace of pure interval training.

Tempo runs

Ideally, a tempo run is nothing more than a steady 20-minute run at T-pace. Subjectively, the intensity of effort associated with T-pace running is comfortably hard. Again, your threshold run effort should be one that you could maintain for about an hour in a race. Although the ideal duration of a steady threshold run is 20 minutes, your running time can vary somewhat to accommodate a particular course.

For example, if your T-pace is 6:00 per mile, and you choose a three-mile course, this gives you an 18-minute tempo effort; or you might go four miles for a 24-minute tempo run. Of course, you could go exactly 20 minutes, using the mile markers to set proper pace, and stop between three and one-quarter and three and one-half miles. It’s not a bad idea to do tempo runs on the track (or even a treadmill now and then) so that you can closely control the pace. Many coaches and runners do longer tempo runs at slower than true threshold pace, and this can yield positive results. Prolonged running at this intensity builds a good sense of maintaining a strong pace for an extended period of time, and as stated earlier, in some instances the demand can be as psychologically intense as a shorter run at true threshold pace.

Also, some runners gradually build up the intensity of a longer “tempo” run until actually running at threshold pace. In any case, I believe in the benefits of tempo runs that are longer than 20 minutes and have designed tables that alter the speed of the run as dictated by duration (see the variations table on page 20 of Daniels’ Running Formula or this article). Using these tables gives runners a better idea of what pace to expect of themselves when out on a tempo run that forces them to run slower than threshold pace and longer than the typical 20-minute duration. The adjusted paces are based on the natural dropoff in maintainable intensity as the duration of a steady run increases.

The variations table shows the mile pace times for tempo runs lasting 20 to 60 minutes, and how much slower the pace is per mile (in seconds) than T-pace. It also shows M-pace (marathon pace) times and how much slower or faster it is per mile than T-pace. If your VDOT falls between the displayed values, just add the appropriate number of seconds per mile or kilometer to your own T-pace for the desired run duration.

Be sure to perform your tempo runs under desirable weather conditions and on relatively flat terrain with good footing because the goal of this workout is to maintain a steady intensity of effort for a prolonged period of time. Hills, rough footing, and wind all affect the ability to maintain a steady pace and interfere with achieving the purpose of the workout. You can monitor your heart rate, but a steady rhythm under constant conditions is what you want in a tempo run.

Possibly the biggest challenge in doing tempo runs is to hold the proper pace and resist turning your tempo run into a time trial. Remember that the proper pace is more beneficial than a faster (or slower) one. This is a good workout for practicing your ability to concentrate on a running task and keep in touch with how your body feels while running comfortably hard.

Begin a tempo workout with a good warm-up of at least 10 minutes of easy running and some light strides. Follow the tempo run with a cool-down, which should include some strides (four or five 20- to 40-second runs at about mile race pace). You’ll be surprised how good you feel about 10 minutes after a tempo run.

My recommendation is that steady tempo runs should last 20 to 60 minutes, with pace adjustments as shown in the table.

How to use tempo runs

A few words of caution regarding how often to repeat identical workouts and monitor progress in a particular type of threshold workout: It’s human nature that runners often want to see progress in their workouts and sometimes try to perform a particular workout at faster and faster speeds over the course of a fairly short period of time.

Trying to compete against yourself in this way is inadvisable. It doesn’t conform to the principle of letting your body react and adjust to a particular type of stress before increasing the amount of stress. It’s better to perform the same workout quite a few times at the same speed, or until a race performance indicates that you’ve achieved a higher fitness level.

One of the best ways to monitor how your training is progressing is to see how much more easily you can perform a particular workout as time goes by. If what used to be a tough workout becomes not so tough after several weeks of training, then that’s a great sign that your training is paying off in a positive way.

At this point, you’re usually ready for an increase in intensity or amount of training. In contrast, always trying to see if you can go faster in a workout that you have done before (the “always hurt as much as possible” technique) can be very misleading in trying to determine how much progress you’re making. With this approach, you always hurt the same (or more), and you never get to experience doing a standard workout with diminishing discomfort. Doubts begin to set in as you ask yourself, “Am I really getting better or just learning to tolerate more pain?” If you often hurt badly in practice, a race won’t be anything special; you should be able to take on more discomfort in a race than you do in daily training.

A more sophisticated way to monitor the degree of stress of a workout is to check heart rates or blood-lactate values at various points during the effort or during recovery. Relying on these more scientific means of keeping track of your progress, however, can prevent you from learning how to do a good job of it on your own. Whether or not you use mechanical or electronic devices to monitor body responses, you should still learn to read your body’s feelings and reactions to the types of workouts that you do.

Please remember not to run faster than the prescribed threshold pace when doing tempo workouts. When you’re having a good training day, it’s not that tough to beat a previous time over a four-mile tempo course. It’s very important, however, to let your ability, based on competitive efforts, determine your training intensities. When a workout begins to feel easier, use that feeling to support the idea that you’re getting fitter. Then, prove that you are getting better in a race, not in a workout.

If you’re in a prolonged phase of training, with no races scheduled, it’s reasonable to increase training intensity without the supportive evidence of better competitive performances. In this case, a good rule of thumb is to increase VDOT one unit every four to six weeks. This is the same as improving your 5,000-meter race time by about 10 to 15 seconds, a substantial improvement in my opinion. If you’re in a maintenance program, which is designed to require the least possible training stress that allows you to stay at a particular level of fitness, there’s no need to increase training intensity (VDOT) or distances. In this case, the best goal is to see how easy standard workouts can feel over time.

When setting up the phases of training, the placement of threshold training might vary in the overall order of the program, based on the individual involved and the event being trained for. Unlike endurance runs, which almost always fall in the earliest phase of a program, threshold training might be emphasized early, at the midpoint, or late in a runner’s training schedule.

Adapted from Daniels’ Running Formula, by Jack Daniels. Copyright 2005. Excerpted by permission of Human Kinetics, Champaign, IL. Available by calling (800) 747-4457 or visiting www.HumanKinetics.com.