There has been a growing body of research shows that polarized training increases:
- VO2 max, your ability to use oxygen to fuel your efforts;
- time to exhaustion;
- adaptation to training stress;
- velocity and power.
With polarized training, endurance athletes do a majority of long, slow distance work at their base aerobic level. And they do a surprisingly small amount high-intensity intervals at a challenging level.
Dr. Stephen Seiler, who has largely been responsible for the popularization of polarized training, studied elite endurance sport athletes (cross-country skiers, runners, cyclists). He and his colleagues found that these athletes spend the majority of the training time (90 percent) simply putting in the time and only 10 percent doing huge effort intervals.
This results in greater systemic adaptation (aerobic capacity) as well as greater muscle efficiency.
This is the essence of Simple Endurance Coaching. Training should not be complicated or overly difficult all the time. The growing body of research suggests that what works is simplicity: run/ ride/ swim/ ski for long, slow distances or go hard.
Blood Markers are Key to Training
Essentially the research focuses on two physiological markers that occur when lactic acid builds in the blood. This is really oversimplified, but at around 2 milliMoles of blood lactic acid, your body has activated key energy systems for aerobic performance. And at around 4 milliMoles, your body does not have the ability to flush the accumulating lactic acid out of the bloodstream.
So researchers have shown that athletes who train for long durations at around 2 mMol and for short durations around 4 mMol have been able to get stronger, faster, and build more adaptation to training stress.
Seiler and others say 2 mMol is around the upper end of the traditional zone 2 – about 75 percent of maximum HR or threshold power.
Dr. Seiler’s Research Featured on Podcasts
He talks about how polarized training is not sexy or complicated. Go fast or go slow. No need to do intervals that have 3 minutes of this, 2 minutes of that, then another 3 minutes of those.
Seiler advocates four, eight, or 16-minute intervals for endurance sports. All of these intervals should be done as hard as possible and as consistently as possible throughout the whole session. That consistency is the key. You need to be able to go as hard as you can for the entire interval.
According to Seiler’s research, the 16-minute interval effort correlates roughly with an athlete’s upper end of their threshold, around 88 percent of maximum heart rate.
The eight-minute intervals will be roughly 90 percent of a maximum heart rate. And the four-minute intervals is roughly 92-93 percent.
Seiler says the four-minute interval, though, may not be the most effective tool since the key is accumulating minutes at a slightly lower intensity. Longer hard intervals are easier to recover from as opposed to the intensity of the shorter interval. The longer intervals also provide the minutes at a high level of intensity, which has shown to be the most important metric.
Recovery for about two-minutes seems to be the good amount between intervals. You will still slowly fatigue.
Harder is Not Necessarily Better
The key variables of intervals are the intensity, volume of the intervals to build the accumulated time. Harder is not necessarily better.
It is true that there are other ways of training that have worked in the past for many athletes! For example, many athletes use tempo or sweet spot intervals to build aerobic fitness because it is shorter than multi-hour hours. This does indeed work to build fitness; the challenge, though, is that tempo and sweet spot rides take longer recovery periods.
I’m not in any way saying those methods are wrong. What we’ve learned in the past few years seems to indicate, though, that polarized training works better than other models.
Periodizing with Polarized Training
As we periodize a training schedule, the relative percentage of training zones doesn’t change much. Low intensity stays low, and will even get lower as you peak, and the high intensity gets a bit higher. Total volume will decrease as the target event nears with a lot of increased rest and recovery.
Peaking can benefit from several anaerobic capacity intervals prior to the target event, but that is kind of different level of adaptation. It is a rapid adaptation, but short-lived. In other words, we can build a peak quickly, but it will not last – especially if you haven’t done the long, slow work.
What Does This Mean for Training?
So what does this mean for general training? Should we do nothing but long rides and eight-minute intervals?
Yes, and no. When I create a program, we might build up to seven intervals of five minutes or six intervals of six minutes. For cycling, the intervals might be done on a mountain bike or on gravel or on a hilly ride to create some variety. For runners and skiers, depending on their desired distances, the intervals would also be a mix.
But the effort, duration, and consistency remains relatively constant.
And the long rides/ runs/ would focus on fun, seeing the sites, talking with friends, or lots of podcast listening. I listen to a lot of podcasts when I ride or run in the middle of the day when no one else is available to hang with!
Got questions about polarized training? Concerns? Email me at pwarloski at gmail dot com or text at 262.705.4892.
For the price of a cup of coffee, we can sit down and talk about your goals, limits, and start creating a training plan that fits your needs.