The Benefits of Lactate Threshold Training for Distance Runners

2014 held one of the greatest races in Boston in recent memory. A fast field was assembled and emotions were highly charged from the tragedy one year earlier.

Right from the start, Meb Keflezighi was at the front of the pack, making it clear he intended give everything he could for a win. Meb quickly made moves to distance himself from the rest of the pack, gaining as much as 90 seconds on other runners with personal bests as fast as 2:05, 2:04, even 2:03. Meb hadn’t cracked 2:07.

Fast-forward to mile 24, two miles left in the race: Meb’s lead was cut to eight seconds by Wilson Chebet, who had been throwing down 4:30 miles to gain ground on Meb.

While very few of us can grind out even one mile at 4:30 pace, we have all been in a situation where our muscles are burning, screaming at us, as we push ourselves past our limits. Meb and Wilson must have been feeling similar racing down the final stretch to the finish line on Boylston Street.

How does one delay the onset of such fatigue? The answer is easy: lactate threshold training. While the work is challenging, the rewards are tremendous!

Lactate threshold training, or tempo runs, are my favorite workouts. They force you to focus on every aspect of the run; force you to push yourself but also remain in control. Simply put, these runs will give you a mental edge needed to finish your next race strong!

By definition, these workouts are more difficult and intense. In short, it means running faster, longer. While many beginner training plans doesn’t include them, they are are critical to helping you meet your goals - whatever they may be.

What is Lactate Threshold Training?

Tempo runs are workouts that are meant to build strength and speed, rather than improve the cardiovascular system’s efficiency in absorbing and transporting oxygen.

In a great article on RunnersConnect, Coach Sarah Crouch describes the various thresholds related to running intensities. Coach Sarah describes the lactate threshold as an intensity at which lactic acid is produced and accumulates more quickly in the bloodstream than your body is capable of clearing it.  When this happens, the pH of your blood lowers as hydrogen ions (a by-product of lactic acid) accumulate in your muscles. This causes the familiar burning sensation of hard work.

By running at or very near your lactate threshold (commonly called a tempo run), your body will become more efficient at clearing lactic acid and reusing it to fuel your muscles. This will allow you to push back the threshold and run faster for longer before fatigue’s burning grip takes hold and slows you down!

In his book Daniels’ Running Formula, Coach Jack Daniels describes these workouts as a way to develop “the ability to endure a greater and greater intensity of effort for a longer and longer period of time”. In other words, he’s saying the physiological benefit of these runs is increased endurance.

Feel the Burn

Coach Daniels says these runs should feel “comfortably hard” and run at a pace you can maintain for about an hour in a race scenario. The exact pace depends on your current level of fitness. If you run a 10k in about an hour, then your tempo runs should be done at 10k pace. For elite runners, these runs are done closer to half marathon pace!

The intensity of these runs should result in a constant level of lactic acid production, but not at a high enough level to flood the bloodstream, forcing you to slow down. Finding this point takes practice and focus, and proper pacing is key. Pushing yourself too hard for too long will not only increase your risk for injury, but it may also minimize the benefit gained from the run and leave you too fatigued to perform optimally in your next workout.

Running the Numbers

For the data-driven runner, Daniels estimates this pace to be between 88% and 92% of your maximum heart rate. Alternatively, he proposes a target of 83% to 88% of your maximum oxygen consumption (VO2Max).  In their book (written by Luke Humphrey) The Hanson’s Marathon Method, Keith and Kevin Hanson put this pace in a broader VO2Max range, between 60% and 90%.

This difference stems from how the two set up their tempo runs. Coach Daniels suggests the quality portion of a tempo run last 20 to 30 minutes and be no more than 10% of the week’s total mileage (or time); however, he also provides a table detailing what the pace of a run should be if it is longer than 30 minutes, which is the pacing followed by the Hansons. If you are training for a marathon, making your tempo runs longer in distance means they are more event specific. This specificity of training is an important principle of training, and will increase the likelihood of your goals being met, or exceeded!

Tempo runs are great for getting a feel for holding a strong pace for a lengthy period of time. They tend to be psychologically demanding due to the focus you will need to maintain your pace, keeping it in the “Goldilocks” zone — not too fast, not too slow, but juuuust right.  This will ensure you are applying the proper stress to your body to gain the desired adaptation — training your body to rely on the aerobic system longer, pushing back the point at which lactate is produced faster than it can be cleared.

Pure Guts Racing

It is said that the “anaerobic threshold separates the champions from contenders.” I can’t say for certain if this particular aspect of his fitness is what won the race for Meb in Boston. Or if Wilson’s kept him from catching Meb.

As the legendary Steve Prefontaine might have said, Meb made it a pure guts race at the end. On that day, he was the only one who could win it.

Working lactate threshold training into your conditioning will give you a mental and physical edge in your races by enabling you to endure faster speeds for longer periods of time. Remember, pacing is key to maximize the benefit of these runs and minimize the risk of injury.

In my next post, I will provide a couple of examples for types of tempo workouts for you to try based on your event and where you are in your training. Until then…

Dream big, work hard!