How to Get Into Ketosis Fast
The low-carb, high-fat keto diet has been shown to improve body composition and increase endurance performance. But getting into ketosis is difficu...
Updated November 11, 2019
Tempo runs were popularized by exercise physiologist and legendary Olympic running coach Jack Daniels. In his training manifesto “Daniels’ Running Formula,” he sought to provide a workout allowing runners to achieve the greatest benefit from the least amount of training, built on “equal parts motivation, injury prevention and training effectiveness.”
How can a runner train hard enough to maximize improvement level, but not so hard as to get burned out or injured?
Enter the tempo run.
Tempo runs have become the bread and butter for long distance runners seeking to boost endurance, speed, and running efficiency at every distance from the mile run to the half marathon. It’s one training tool every runner needs in their training plan.
Tempo runs are a threshold run workout. Specifically, tempo running is done at a training pace intensity just at or below lactate threshold pace. In most experienced runners, this is probably around 10 -15 seconds faster than 5k race pace. For distance runners preparing for longer races, tempo pace may be closer to half marathon race pace.
At threshold pace, the body begins to accumulate a byproduct known as lactate in the bloodstream. This “onset of blood lactate” (OBLA) is associated with performance decline and fatigue.
The goal of a tempo run is to maintain exercise intensity right at this threshold for a long period of time.
The benefits derived from tempo runs stem from teaching your body to run hard for a longer distance while tolerating and metabolizing lactate, and training your mind to deal with the discomfort that occurs while riding the line at threshold intensity.
Tempo runs improve endurance performance by boosting the body’s ability to clear out and utilize lactate in the bloodstream.
You heard right–use lactate. No longer the arch enemy of distance runners, lactate is now recognized as a byproduct runners and athletes can use as a fuel during prolonged exercise.
While lactate and fatigue go hand in hand, the buildup of lactate itself does not impair performance or lead to muscle soreness. The burning sensation felt during intense exercise isn’t caused by lactate. This is a common misconception among distance runners.
During a lactate threshold run, your body is actually able to recycle lactate produced in the muscles, using the lactate as fuel. In this process, lactate is shuttled throughout the body where it can be metabolized; if it reaches the liver it can even be turned back into glucose, then shipped back to contracting muscles crying out for energy.
At exercise intensities above the lactate threshold, more lactate is produced than our body is capable of clearing and it begins to accumulate in the blood. Here, the real culprits for fatigue are unmasked. Under conditions of low oxygen and increased energy demand (like springing for the finish line), lactate is produced faster than the body can metabolize it. Lactate associated with a proton then becomes lactic acid. Those acidic protons? They lower blood pH and contribute to the metabolic mayhem that eventually contributes to fatigue and decreased performance.
The goal of tempo runs is to increase lactate threshold, also known as anaerobic threshold. Why does lactate threshold matter for distance runners?
The ability to recycle and remove lactate is imperative for endurance athletes.
Having a high lactate threshold has been shown to be a more important indicator of aerobic fitness and performance than V02 max. Among athletes with the same V02 max, those with a greater lactate threshold are superior performers.
Lactate threshold responds well to training. In already well trained athletes, it will take a high intensity and volume of exercise to improve max oxygen capacity, and sometimes, performance can improve without a boost in aerobic fitness. Tempo runs can improve endurance performance independent of V02max increases,
Determining your goal pace for a tempo run by measuring lactate threshold can be complicated and unnecessary. Direct LT determination often involves advanced laboratory tests. Other methods exist to estimate LT, including use of a VDOT chart, the Conconi method, and a “30 minute flat out” time trial.
Heart rate can be used to find and set tempo run pace. Most tempo runs are prescribed to be around 82% - 90% of your maximum heart rate. This has shown to be associated with the LT in athletes and can be continuously checked using a heart rate monitor.
If data isn’t your jam, tempo runs can be done solely based on effort level. Learning to gauge and hold a sustained tempo effort is a major purpose of tempo or lactate threshold runs.
Conduct a tempo run at a comfortably hard pace. At the end of the tempo run, you should feel like you could have continued on at the same pace for a little while longer. Most coaches suggest tempo pace is something sustainable for about an hour. If you’re struggling into the finish, you did it wrong.
The simplest way to find tempo pace? The talk test. Research indicates a speed slightly above that at which people report comfortably reciting the “Pledge of Allegiance” correlates extremely well with lactate threshold.
No matter the method used, it’s important to remember specific goal pace may not be attainable from one tempo to the next. Effort is the important factor to consider in tempo runs. On a bad day, tempo pace might feel more like race effort.
The main goal of a tempo run is to increase your speed at lactate threshold. This means you’ll be able to run faster before lactate starts accumulating in your bloodstream.
Training at tempo pace consistently improves lactate threshold and other performance measures. Middle-aged and young men who trained at LT for 20 weeks increased power outputs at lactate threshold pace by 38% - 42%.
Tempo runs may also lead to changes in enzymes responsible for using lactate. Increased clearance ability means less lactate accumulation. Runners who added one 20-minute tempo run to their training program each week increased their ability to metabolize lactate, indicated by an increase in the enzyme lactate dehydrogenase (LDH) in the heart.
Tempo runs may help you train to run a longer distance at a faster pace before your body starts preferentially oxidizing carbohydrates for fuel. After threshold training, the crossover point where runners begin to produce lactate from glycolysis occurs at the same percent of maximum heart rate, but at a faster pace.
One way to take your tempo running to the next level is to try exogenous ketone supplements. Experiments using ketone esters show that athletes can hold the same intensity of work with a lower level of blood lactate, in fact levels were 30% lower. Co-ingesting ketones and carbohydrates can have a “glycogen sparing” effect, thereby allowing athletes to run harder for longer distances and find another gear.
Endurance races are a test of who can handle the most pain over a long period of time. The athlete who train to endure discomfort more than the competition often finds their way to the podium.
Tempo runs are favored by coaches and athletes for their ability to instill mental toughness and grit. A tempo run is like holding your hand above a flame. How long can you last before you get burned?
Tempos aren’t fast enough to cause a bonk, and aren’t slow enough to continue forever. The “slow burn” of tempo runs is what makes them particularly grueling type of speed workouts, but a tantalizingly effective one.
Running at threshold pace teaches you how to endure pain. It isn’t easy to run at your breaking point for 20 - 60 minutes. The urge to slow down and end the uncomfortable burning sensation is real, and pretty darn tempting. Fighting against this urge requires toughness that can only be gained through practice.
Concentration is also a crucial asset for distance runners that is improved through threshold training. Learning how to concentrate on goal pace might be one of the most important things you can learn from a tempo run. It’s the reason tempo creator Jack Daniels recommended avoiding tempo running on a treadmill. The ideal, indoor environment may reduce the concentration required to maintain goal pace, compromising the workout’s psychological benefit.
Repeated tempo runs also breed confidence. After having completed several tempo workouts, you learn that you can tolerate a hard pace for a long time. You won’t break down. Recall this mentality during the race.
The beauty of the tempo run is its simplicity.
However, threshold running can take several forms in addition to continuous run. The goal remains the same: maintain goal pace throughout the entire workout and finish feeling like you have a little left in the tank. Remember, tempo runs are not race simulations, and it’s important never to run faster than your goal pace, even if you’re feeling superb.
Daniels described the tempo as a simple, steady and controlled run lasting about 20 minutes at threshold pace. The emphasis here is on steady effort level.
Why 20 minutes? Daniels chose this particular duration because it was long enough to provide a challenge, but short enough to leave runners fresh for the next day’s training. Are tempo runs designed to destroy you? The answer is no.
For a standard tempo workout, run an easy 1 - 2 mile run as a warmup, followed by 20 minutes at your threshold pace, and end with a 1 - 2 mile run as a cooldown. Runners in marathon training or half-marathon training may choose to increase the distance of the warm-up, cooldown, and even the tempo run itself. Individualize this workout to fit the needs of your training plan.
Cruise intervals are a hybrid of tempo run and speed work, aka interval training. They involve threshold-paced running (tempo pace) where the workload is divided into intervals (typically around one mile) separated by brief recovery periods.
The rest intervals are short–about 30 - 60 seconds in length–just enough time to catch your breath but not enough time to fully recover. This part is important; it’s necessary to keep blood lactate elevated, just like a continuous threshold run. The little breath catcher is just a tease for your lungs.
This adaptation of the tempo run allows runners to complete more work at tempo pace than they could reasonably accomplish with a continuous run. Rather than run four miles non-stop, a cruise interval workout may involve six, one-mile intervals at identical pace. The brief rest periods allow more work to be done at threshold pace with a reduced stress level.
It may be a good idea to integrate this speed workout every other week into your training plan. Instead of the usually-scheduled tempo, substitute a cruise interval workout to spice up your training and squeeze in some more mileage at threshold pace.
For most runners, having the dedication to impart self control during workouts is just as important as having strong work ethic. This is particularly true for tempo runs. The benefits come from sticking to a particular goal pace, which often calls for restraint.
Tempo runs should become a staple in your training program regardless of whether you're preparing for a 10k, half marathon, or an ultra.
Integrate one tempo run per week into your training plan, mix in a cruise interval in place of a weekly tempo, and bookend tempos between easier training days.
While not as stressful as a harder speed workout, you still want to be fresh coming into the tempo and allow adequate recovery.
Monitor training progress by assessing subjective feelings during a tempo run. If running the same pace requires a lower effort level from one week to the next, it may indicate improved fitness. This is especially true if your tempo runs take place on the same course. It may be best to have a consistent weekly route for your tempo runs. Sure, it might be scenically boring, but this allows you to compare one tempo run to another. Taking a read of your heart rate can also indicate whether you’re pushing too hard on a particular day.
Same pace as last week but a heart rate that’s ten beats per minute faster? Might be a good day to dial back on the pace.
Many runners fall into the trap of trying to beat last week’s tempo run time. It can be tempting to squeeze out just a bit more effort to get a tempo run PR. This might involve dipping down closer toward race pace effort. The only thing this accomplishes is making your training log (or Strava account) look a bit more impressive. In reality, it will take away from the rest of the week’s training and possibly hamper an upcoming race. Nobody likes a workout hero.
Don’t value pace over effort level or intensity. An off day mentally, windy conditions, hills, extreme temperatures–all can influence pace during a tempo run. In this case, it’s important to maintain steady effort and ignore whether your splits vary from mile to mile or aren’t as fast as you’d like.
It may also be tempting to do tempo runs often, since they aren’t super stressful on your body. However, not every run counts as a speed workout. Proper rest days are needed to adapt to training. Polarize your training with rest, recovery, and enough off days.
The goal is to get better in the race, not to get better at doing a tempo run. Impressive workouts mean nothing if you get to the starting line overly-fatigued.
New to tempo runs or transitioning back into faster running after base building or time off? Starting with a weekly 20-minute tempo run might be the perfect workout for a low-stress but challenging introduction to speed workouts.
As you advance in fitness and threshold pace begins to feel easier, try first increasing the mileage (or total duration) of your tempo run. After a few weeks of 20-minute tempo runs at threshold pace, increase to a longer period of time, maybe 22 - 25 minutes at the same pace. Once fitness progresses more, threshold pace will naturally get faster (at the same relative intensity). Don’t force pace; let it come naturally.
Tempo runs are great way practice hydration and nutrition for race day since they are performed closer to race pace than a regular training run. If you’re planning on fueling before the race, better to practice than lose time while choking down a cup of water at mile nine. Plan your tempo run on a one-mile loop and set up water stops to practice hydration on each pass. Hydration and nutrition can also be practiced during your long run, since this will mimic race-day if you’re training for a full- or half-marathon.
Tempo runs are included in nearly every training regimen of advanced and recreational distance runners, and have been for decades. In Kenya, tempo running is the most popular training method, with some reports showing nearly 14% of weekly mileage run at around lactate threshold.
Add this tried and true workout to your training plan for a new boost in performance. Optimizing your endurance is only 20 minutes away.
The low-carb, high-fat keto diet has been shown to improve body composition and increase endurance performance. But getting into ketosis is difficu...
Monitoring ketone levels in urine is important for both diabetics and those waiting to maintain ketosis. Here's what to look for, how to test and t...
VO2 max might be the truest representation of endurance fitness there is. While elite runners and cyclists train their bodies to use a high volume ...
Are all calories created equal? Not on the keto diet. Weight loss has emerged as a primary incentive for going keto. That's not driven by the amoun...
A ketogenic diet, or “keto diet,” refers to an extremely low-carbohydrate, high-fat pattern of eating. This article dives into the history of the k...
BHB stands for beta-hydroxybutyrate, one of the three main ketone bodies. It's a clean-burning energy source for both the body and the brain. What'...
Ketone salts, also known as BHB salts, provide the body with a way to enter ketosis. But the results are mixed. There are a few options for someone...
Runners chase speed. For many, it's a lifelong pursuit. The connection between the body and the mind is important for speed, and harnessing both wi...