High Intensity – 80/20 Endurance

High Intensity

“Believe in your system, and then sell it to your players.”
—Billy Donovan

I love the above quote from basketball coach Billy Donovan. Like Donovan, I believe that athletes perform better when they understand and believe in their system of preparation. The very same system will yield very different results depending on whether it is understood and believed in by the athletes following it or blindly followed without a sense that its various elements form a coherent whole that is different from, and superior to, the systems followed by their competitors.

In my one-on-one coaching I make a consistent effort to help my athletes understand why they’re training as they are. Among the tools I use in this effort is the veal cutlet metaphor. It’s laughably simple, but that’s the point. The simpler you can make the conceptualization of your training system, the likelier it it the athlete absorbing that description will understand and accept it.

Now, personally, I don’t eat veal for ethical reasons. But this is a metaphor, not a menu. If I did eat  veal, I might try this delicious-looking recipe that I found on Bon Appétit:

24 ounces veal scallops, pounded to 1/8-inch thickness
2 cups panko (Japanese breadcrumbs)
½ cup all-purpose flour
2 large eggs
1 cup dry white wine
1 cup low-salt chicken broth
¼ cup fresh lemon juice
¼ cup fresh thyme leaves
¼ cup chopped shallots
18 tablespoons (about) chilled butter, cut into tablespoon-size pieces, divided
2 tablespoons whipping cream
2 teaspoons chopped fresh chives

That’s a lot of ingredients, but really the recipe comprises three basic elements: meat, sauce, and seasoning. In this respect, it resembles thousands of other recipes. The meat-sauce-seasoning combo is a classic formula in a variety of cuisines, French traditional especially. It just works, like a black-and-gold color combo on a sports uniform and a drums-bass-guitar combo in rock ‘n roll.

Endurance training—when done right—features exercise equivalents of meat, sauce, and seasoning. Get ready to see a metaphor tortured to within an inch of its life.


In cooking, meat does the heavy lifting, providing the bulk of the calories, micronutrients, and satiety in a recipe. A dish made up of sauce and seasoning only might taste okay, but it wouldn’t be very nourishing or satisfying.

In endurance training, low intensity is the meat—the foundation of the process. At the elite level, athletes perform between two in three and three in four their workouts entirely at low intensity, and research has shown that recreational athletes who break out of the moderate-intensity rut and emulate this practice attain higher levels of fitness and performance.

Because low intensity is so gentle, it is the gift that keeps on giving. The more low-intensity work you do, the fitter you get. When in doubt about how to level up as an endurance athlete, add low intensity to your routine.


In the recipe offered above, the sauce is the star of the show—the thing that dazzles the palate and makes you want to eat it again sometime. If you could only have one or the other—the meat or the sauce—you’d be better of healthwise choosing the meat—but thank goodness you don’t have to choose!

You’ve probably already guessed that moderate and high intensity are the sauce of endurance training. The process would be so boring without moderate-intensity tempo workouts, high-intensity speed workouts, and the like. Combined in the right proportion with meat (that’s right: 80/20), these harder workouts produce fitness gains that are impossible to achieve any other way. But as with sauce, too much ruins everything. We all love butter, but you don’t want your veal cutlet drowning in it, nor do you want to focus more than one out of every three to four workouts on moderate or high intensity. If ever you’re tempted to do so, remind yourself: sauce.


Some people don’t like well-seasoned food. They are perfectly content with bland fare. I don’t understand them, but their existence proves that seasoning is not strictly essential to a pleasant dining experience. All great chefs, however, love seasoning, and this consensus proves that bland eaters are missing out. Backwoods Billy Joe might not notice if the thyme was missing from the veal recipe I gave you, but the person who came up with it sure would!

Similarly, strength and mobility training, which function as the seasoning of endurance training, are not strictly essential to maximizing endurance fitness. Hardcore advocates of these methods may argue otherwise, but their argument is undercut by the plethora of world-class endurance athletes (including a number of notable East African runners) who largely eschew these methods. But a method can be both inessential and valuable, and strength and mobility training are extremely valuable. The latest evidence comes from a 2023 study by Swedish researchers showing that runners who adhered faithfully to a weightlifting and foam rolling program for 18 weeks were 85 percent less likely to get injured than runners who adhered to the same program less faithfully or did not follow it at all.

Let’s Eat!

So there you have it: Low intensity is the meat of endurance training, moderate and high intensity are the sauce, and strength and mobility training are the seasoning. All three elements make important contributions to a cohesive whole, but it’s important to get the proportions right. Keep this metaphor in the back of your mind over the coming season and see if it doesn’t help you “believe in your system” and get better results from it.

If the fastest swimming, cycling, and running you do is in races, you’re not training right. Every triathlon training program should include speed work, or efforts that exceed race intensity. Speed work not only changes your perception of race intensity, making it feel more comfortable, but it also enhances fitness in ways that slower training does not.

There are right and wrong ways to incorporate speed training workouts. Doing speed work the right way is not difficult. A top triathlon training tip is to copy how professional triathletes go about it (which is not to say you should try to go as fast as they do!). Incorporating speed exercises all comes down to obeying these three simple rules.

Rule #1: Do some speed training workouts year-round.

Speed training workouts can be done year round

The term “periodization” refers to the practice of dividing the training process into phases and assigning a distinct fitness objective to each. Traditionally, the first phase, known as the base phase, is all about building general aerobic fitness and endurance through large and increasing amounts of low-intensity training. Speed work is excluded from this phase because maximizing overall training volume is easier when intensity is kept low.

These days, however, most elite triathletes include a small amount of high-intensity swimming, cycling, and running in the base phase, and you should too. The reason is that when speed work is completely eliminated from training, the athlete loses the dimension of fitness that comes from speed work and makes it harder to get it back in later phases.

Just one small dose of high-intensity swimming, cycling, and running per week during the base phase will enable you to avoid digging this all-too-common hole. I recommend doing very short efforts at or close to maximum intensity, such as 8 x 25-yard sprints in the pool and 8 x 20 seconds uphill on the bike or the run.

Rule #2: Keep your total volume of speed training workouts low.

After the base phase of training comes the peak phase. During this period, which should begin 6-12 weeks before a race, you will want to increase your volume of speed work while keeping your overall training volume steady. But even at this time, speed work should account for no more than 10 percent of your total training volume.

Again, let the pros be your guide. In 2012, Iñigo Mujika of the University of Basque Country monitored the training of elite triathlete Ainhoa Murua as she prepared for the London Olympics (where she placed seventh). He found that she spent 10 percent of her total swim training time, 2 percent of her cycling time, and 7 percent of her running time at high intensity. These numbers are normal for elite triathletes and they should be the norm for you too.

While a little triathlon training for speed goes a long way, more than a little is counterproductive. This was shown in a 1999 study involving elite middle-distance runners. For the first several weeks of the study period the runners completed six runs per week, all at low intensity. Then they switched to a schedule of five low-intensity runs and one high-intensity run per week for a few weeks. Finally, they switched to a schedule  of three low-intensity runs and three-high-intensity runs per week. The runners produced the best results in a fitness test when they were doing one run per week at high intensity and got the worst results when they did speed work three times per week.

Here’s an example of a sensible breakdown of training intensities during the peak period of training:

Monday: Rest

Tuesday: Swim 1500 yards w/ 3 x 200 at moderate intensity

Wednesday: Bike 50 minutes w/ 8 x 1 minute at high intensity

Thursday: Run 45 minutes w/ 6 x 3 minutes at high intensity

Friday: Swim 1500 yards at low intensity

Saturday: Bike 70 minutes + run 10 minutes at low intensity

Sunday: Run 10 miles at low intensity

Rule #3: Make your speed work increasingly race-specific as the training process unfolds.

swimming for speed training workout

The format of your speed workouts should evolve from week to week as the training process unfolds. The idea is to make your high-intensity sessions increasingly race specific. What does this mean exactly? It means that your intervals should become longer and slower (while remaining faster than race speed). The reason is that the true goal of speed work is not to make you faster—it’s to increase your fatigue resistance at higher speeds.

In the pool, I suggest starting with 25-yard sprints and moving step by step from there up to 200-yard repetitions. You should include longer intervals in your training as well, but these don’t count as speed work. On the bike and on the run, start with 20-second hill sprints and transition incrementally to intervals of 3 to 5 minutes. Don’t completely give up the really short stuff, though. Sprinkle in a few sprints even during the last few weeks before a race to maintain your highest gear.

Love it or loathe it, speed work is a critical component of effective triathlon training. But there are right and wrong ways to go about it. Now you know the right way.

$ubscribe and $ave!

  • Access to over 600 plans
  • Library of 5,000+ workouts
  • TrainingPeaks Premium
  • An 80/20 Endurance Book


30 day money back guarentee

For as little as $2.32 USD per week, 80/20 Endurance Subscribers receive:

  • 30-day Money Back Guarantee