Fast Talk podcast, ep. 51: Polarizing your training, with Dr. Stephen Seiler

Dr. Seiler has revolutionized our understanding of endurance training. In this episode, we'll take a deep dive into his theories.

Photo: Casey B. Gibson

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The VeloNews Fast Talk podcast is your source for the best training advice and most compelling insight on what it takes to become a better cyclist. Listen in as VeloNews managing editor Chris Case and our resident physiologist and coach, Trevor Connor, discuss a range of topics, including training, physiology, technology, nutrition, and more.

EPISODE 51 OF FAST TALK is one that Coach Connor and I are particularly excited about. In fact, Trevor is so enamored with our guest’s research that he refers to him as the Jay-Z of physiology. I don’t really know what that means, but I’m fascinated that Trevor knows who Jay-Z is. But I digress.

Dr. Stephen Seiler has revolutionized our understanding of endurance training. Perhaps you’ve heard us refer to his findings in previous episodes. We’ve discussed several of them in the past, just not at length and in one place. Today it all comes together, and we’re privileged to have Dr. Seiler to help explain what can be, at times, some complex science.

In this episode, we’re going to take a deep dive into many of his theories, including:

1. Why both coaching techniques and the science have become so biased toward high-intensity training when that isn’t how the best athletes train.

2. Dr. Seiler’s three-zone model of training (see below). There are many zone models out there. Most of us use five zones for training, but some models have as many as nine. In his research, Seiler has pointed out that when we test, there are two physiological breakpoints. One is our anaerobic threshold, or MLSS. Your coach may call it FTP. It tends to be right around the point where we hit 4 mmol/mL lactate. The other breakpoint, which is lower — about 85 percent of anaerobic threshold and at 2 mmol/mL of lactate — is often called our aerobic threshold. Seiler feels these breakpoints define three physiological zones. Zone 1 is below the aerobic threshold, and what we call easy base training. Zone 2 is between the breakpoints and has many names, including no man’s land or sweet spot. The third zone is our high-intensity training zone.

Figure 1. Seiler’s three-zone model is based around two physiological breakpoints.

3. Next, we’ll talk about how, by studying elite athletes, Seiler found a remarkable consistency: most endurance athletes train about 80 percent of the time in Zone 1, around 15 to 20 percent in Zone 3, and very little in Zone 2. This has become known as polarized training.

4. We’ll take a deep dive with Dr. Seiler into both Zone 1 and Zone 3 training and how to approach both. A theme will start to emerge, and you’ll hear one of the top physiologists in the world repeat it again and again: keep it simple. That might seem surprising, but the research is clear: complex intervals and overly detailed training plans may hurt more than they help. Ultimately, it may be as simple as accumulating time in the various zones in the right ratios.

5. Finally, we’ll discuss how these principles apply specifically to training. Seiler’s research includes Nordic skiers, rowers, runners, and cyclists. So be warned, at times you’ll hear some concepts that may be unfamiliar to you. For example, cycling is one of the few places where endurance athletes do five-hour workouts. In other endurance sports, they add volume by doing two-a-days.

Full disclosure, this episode is a deep dive. If this is your first time listening to Fast Talk, we recommend starting with an appetizer. In episode 14, we discuss the difference between polarized and sweet-spot training, which give you the context you need to follow this conversation.

Our featured guest is, of course, Dr. Stephen Seiler, a professor of sports science in Norway, where he has lived for 22 years. But no, that’s not a Norwegian accent. He received his Ph.D. from the University of Texas. Dr. Seiler is now on the executive board of the well-respected European University College for Sports Science.

If you want to learn more about his research, he’s on Twitter and tries to make all of his research and presentations available for free on Research Gate.

In addition to Dr. Seiler, our guests include:

Grant Holicky, a head coach at Apex Coaching, a highly respected coaching center here in Boulder that has produced many Olympic and world champion caliber cyclists. Holicky talks with us about the mistakes of doing too much training in that middle zone.

We’ll also hear from past Canadian national champion Andrew Randall and past national mountain bike coach Steve Neal who, together run the Cycling Gym in Toronto, a city where traffic, bad roads, and cold weather dominate. The conditions justify doing lots of intensity on the trainer, but Randall and Neal explain why they don’t take that approach with their athletes and still follow a polarized model.

Finally, we hear from Larry Warbasse, the 2017 U.S. national road champion who rides for Aqua Blue Sport. He gives a few examples of how top pros have figured out what seems to work for them, without necessarily having read the research or knowing the scientific terms.

So, are you ready to go slow to be fast? If so, this is the episode for you. Let’s make you fast!


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