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Lactic threshold training runs

What is a lactic threshold run?

Definition of lactic threshold
We need oxygen like a fish needs water. When our bodies move at a rate faster than we can deliver oxygen to our muscles, we summon energy anaerobically. A byproduct of this “borrowed” energy is lactate, which increases acidity in our muscle cells and slows our movement until we can regain proper oxygen levels. This article sheds more light on the science and answers the question of why this buildup leads to soreness.

The line between aerobic and anaerobic is known as our lactic threshold (LT), the point at which lactic acid builds up in the blood at a faster rate than it can be removed.

When to do lactic threshold workouts
Since increasing this threshold directly relates to running performance – i.e., how far and fast you can run – most coaches and training plans prescribe a weekly lactic threshold workout for any race distance.

Pace goals of lactic threshold workouts
Every runner has a different lactic threshold. While the most accurate way to measure your lactic threshold may be through blood samples and graded exercise tests in the lab with a professional, many do not have the time, funds, or access to such facilities. You can find similar results from completing a 30 minute time trial on a track. You can also find similar results by plugging your recent race times into various running calculators. Many coaches go by the rule that LT pace is that which you can race for 50-60 minutes. While many coaches and training plans prescribe weekly lactic threshold workouts, they differ in duration, intensity, and format.

Training method Recommendations
Hal Higdon In all of his training plans, Higdon prescribes tempo runs, which he says “are very useful for developing anaerobic (lactic) threshold.” His tempo runs range from 30-60 minutes; begin with a 10-15 minute warm-up; end with a 5-10 minute cool down.For a 45 minute tempo run, 20-30 minutes will be spent running at a quality pace. He recommends a gradual increase in pace, peaking at near 10K pace two thirds of the way through, holding that pace for a few minutes, and easing the pace back down again.Higdon calls tempo runs the “thinking runner’s workout,” one that can be “as hard or easy as you want to make it.”
Jeff Galloway In his book, Galloway recommends completing a weekly threshold interval workout: 800-1600 meters at a pace 20-30 seconds faster per mile than marathon goal pace. After each, give yourself a 2-3 minute recovery walk or jog. Start with a few reps and build them up throughout your training cycle.
FIRST One of the three weekly workouts in the FIRST plan is a tempo run, which builds from 2 miles to 8 miles over a training cycle. In this plan, you can estimate your tempo pace by subtracting 15 seconds from your target half-marathon pace. You can select a more specific pace by using their pace calculator. Each tempo run is sandwiched by slow warm-up and cool down jogs.
Hanson Method In their 18 week beginner marathon plan,  runners add a 5 mile tempo run at week 6 and gradually build to a 10 mile tempo run at week 16. In their advanced plan, runners begin a 6 mile tempo at week 3 and build to a 10 mile tempo at week 16.Tempo running is completed at a pace well below runners’ lactic threshold. For marathon training, the Hanson method calculates tempo pace as goal marathon pace, and for half-marathon training, they calculate tempo pace as goal half marathon pace.
Pete Pfitzinger More than a decade ago, Pfitzinger argued that tempo runs are “the single most important type of training for distance runners.” And since that time, after consideration and study, he has revised his approach: “Rather than limiting tempo runs to a maximum of 45-50 minutes, I now agree that there are benefits from a slightly less intense version of up to about 80 minutes.” Pfitzinger estimates your LT pace lies in-between your 15K and half-marathon race pace. His sessions begin with a 2-3 mile warm-up followed by 4-7 miles at LT pace. In his 18/70 marathon plan, I counted 5 LT workouts interspersed with various other workouts.
Greg McMillan McMillan recommends two workouts to improve your lactic threshold: a steady state tempo run and tempo intervals. First, McMillan recommends using his training calculator to find your appropriate pace. He recommends beginning with 10-20 minute tempo run to learn pace and building to 30-40 minutes. Any farther, he warns, “it really becomes a race.” As an alternative to the weekly tempo run, tempo intervals break the steady tempo run into a series of runs between 2 and 15 minutes, completed at a pace slightly faster than your lactic threshold pace, followed by a brief period of rest.
Jack Daniels Like Pfitzinger, Daniels prescribes two categories of lactic threshold workouts, tempo runs, and cruise intervals. Daniels calculates threshold pace is about “83 to 88 percent of VO2 Max, or 88 to 92 percent of VO2 Max or maximum heart rate.” To simplify this, you can compute your threshold pace with Daniels’ running calculatorTo Daniels, a tempo runs is [ideally] “nothing more than a steady 20-minute run at T-pace.” But he recommends sustained runs of 20-60 minutes. Following his plan, runs at T pace that go beyond 20 minutes are adjusted to simulate “the natural dropoff in maintainable intensity as the duration of a steady run increases.” He recommends beginning a T workout with a 10 minute warm-up followed by light strides and ending with a cool down with four or five, 20-40 second runs at mile race pace. He says, “You’ll be surprised how good you feel about 10 minutes after a tempo run.”

Lactic threshold in a nutshell
Running aerobically should feel comfortable, sustainable. But to improve as a runner, you must be willing to move beyond your comfort zone; you must cross your anaerobic (lactic) threshold. Over time, what you consider to be your comfort zone will expand; your body will be more efficient in removing lactic acid as it develops.

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Written by Stephen Marcin.

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