Polarized Training and Sweet Spot Training are sometimes seen as competing training philosophies. Dr. Stephen Seiler coined the term ‘Polarized Training’ and Frank Overton the term ‘Sweet Spot Training’ but in both cases many others have adopted these philosophies so there is considerable variation in the actual training plans that are derived from each of them. That said, I am going to concentrate on Seiler’s and Overton’s versions of these philosophies. Back in the blog post where I described my discovery of Seiler I also mentioned that my first exposure to Seiler was my first experience getting training information from a podcast and that this medium had a number of advantages as a source of learning. So, in addition to concentrating on Seiler and Overton, I am going to rely primarily on their podcasts because these tend to be more flexible and realistic, giving me, I feel, a better sense of what these different philosophies are in the real world. I am not going to attempt to reference each point I make, rather, I am going to give a couple of general references to Overton podcasts at the end of this post^. (I have previously referenced Seiler podcasts.) Finally, there is a third name I need to mention, Dr. Andrew “Andy” Coggan. Dr. Coggan was one of the pioneers of the use of power meters in training and back around 2004 gathered together a group of athletes, coaches, and scientists to develop systems for using power meter data, a group including Overton, and it was the discussions of this group that Overton used to develop his concept of Sweet Spot Training.
The first thing we need to consider is the similar, specialized audiences for these two philosophies. What these audiences have in common is that they are bicycle racers, road racers in particular. (Later in this post I will discuss some differences in their audiences.) I realized this when I attempted to map these philosophies onto the training advice of the coach I use, Coach John Hughes. To my surprise, I couldn’t do it. What I realized is that Hughes writes mostly for participants in distance challenges, century riders and randonneurs for example. Training for these riders is much more about building endurance than speed. It is not that speed does not matter, but rather that speed is secondary to endurance and that the relevant speed is steady state speed, jumping to join a breakaway or having a sprint at the end of the ride is unlikely to be useful to the riders Hughes coaches. This results in very different training plans than those used by road racers.
So what is Sweet Spot? I have mentioned it before as an Intensity Zone used by Coach Hughes. His basic definition of intensity zones divides intensity levels into seven zones. On top of that basic system, he defines Sweet Spot as extending from the very top of his basic Zone 3 through the bottom half of his basic Zone 4. (For the remainder of this post, when I refer to an intensity zone, I am going to be using the Hughes seven zone system.) Overton defines the intensity level of Sweet Spot more broadly, as 84% to 97% Functional Threshold Power (FTP) which translates to the top half of Zone 3 and almost all of Zone 4 in the Hughes system. Coggan has an even broader definition which includes everything from the top of Zone 2 through the very top of Zone 4.
Sweet Spot is an intensity zone but it is also something more. To put this “something more” into context, both the Sweet Spot and Polarized philosophies have in common a firm commitment to periodized training. A minimal version of race-directed periodization is a Base phase during which aerobic fitness is developed followed by a Build phase during which specific racing adaptations (speed, power) are developed followed by a Taper phase in which a small amount of Fitness is sacrificed to substantially reduce Fatigue in order to maximize performance (Form) followed by the race followed by recovery. The period in this process where the difference between the Sweet Spot and Polarized philosophies is important is during the Base phase. The simplest description of the difference between Sweet Spot and Polarized training is that Polarized training recommends many hours of Zone 2 riding during the Base phase whereas the Sweet Spot philosophy recommends fewer hours of the more intense Sweet Spot intensity training during the Base phase. Both are intended to build an aerobic base and the primary argument between these philosophies is which of these intensities is better at doing that.
In a podcast, Coggan generalized this question in a way I found helpful. He opined that between somewhere in Zone 2 through the top of Zone 4, all that mattered was the product of time and intensity. That is, if Zone 4 has twice the intensity of Zone 2*, 1 hour in Zone 4 has almost exactly the same training effect as 2 hours in Zone 2. My impression (again, from podcasts) is that Seiler would disagree. To explain why, I have to talk about blood lactate levels. What makes doing so confusing is that blood lactate can be used as the basis for an intensity zone system that is very different from the Hughes seven zone system I am using in this post. For that reason, I am going to refer to these as Lactate Brackets rather than Zones.
There are three Lactate Brackets, Bracket 1, 2, and 3 corresponding to low, medium, and high levels of blood lactate and thus intensity. Zone 2 lies in the low Lactate Bracket 1 whereas Zone 4 lies in the medium Lactate Bracket 2 and thus I think Seiler would argue that there is likely to be fundamental physiological differences between them. One consequence of such differences would be that a ride in the Lactate Bracket 2 will produce much more fatigue than a ride in Lactate Bracket 1, thus limiting the amount of training that can be done. Assuming Seiler is correct, given unlimited time to train, an athlete would be able to build up much more aerobic fitness riding in Zone 2 than they could riding in Zone 4 because fatigue would limit the Zone 4 rides long before it will limit Zone 2 rides.
One confounding factor in comparing Sweet Spot and Polarized training is that there tends to be a difference in the intended audience for Polarized and Sweet Spot training. Advocates of both will argue that theirs is the best approach for almost all racers but their primary targets seem to be different subsets of racers. Seiler mostly coaches full time athletes who have almost unlimited time to train. Many of the clients of Overton are amateur athletes who have to fit their training in around a job and family responsibilities. It may well be that Sweet Spot training is better if you have a limited time to train but that Polarized training is better if you have unlimited training time. Also, we must never forget individual variation. It is possible that one athlete may reach a higher peak performance with Sweet Spot whereas another may do so with Polarized Training.
So which is better, Sweet Spot or Polarized? I am far from an expert on the training literature, but so far I have not come across a study that answers that question in a way I find convincing. In a podcast, Dr. Coggan, who is an expert on the training literature, said more or less the same thing. In the first place, it is not even clear what the question is. Is it that which provides the greatest benefit if there are no constraints (e.g. if there is no limit on training time)? Is it that which provides the greater benefit to the greater number of athletes? Is it that which might be problematic for many athletes but which, if applied to the most gifted athletes, would produce the highest level of fitness? How long should the experiment run? For a year? For multiple years? For the length of an athlete’s career? In the second place, the chances of getting the resources needed to do the right experiments are effectively zero. So unless the differences are dramatic we will probably never know the answer.
While investigating Sweet Spot training for this post, I noticed one additional, relatively unrelated aspect of Overton’s approach to training and that is extensive use of a training load model developed by Coggan. This model is most easily available as part of the commercial “Training Peaks” software package. This specific training load model is designed to use power meter data. However, Coggan’s model was originally based on the heart rate-based model of Dr. Edward Bannister, so it should be possible to do the same kind of tracking using heart rate data. As I listened to Overton, I became very jealous of how he could use this model to track the projected impact of each ride on his Form, Fitness, and Fatigue. Was there some way I could do the same thing? If so, would I have to purchase a power meter and the Training Peaks software or could I use a less expensive heart rate monitor and publically available software? As I looked at Coggan and Bannister’s models more closely, I found parts of them with which I disagreed and/or where my age and genetic background would require different parameters than these racer-targeted models used. Could I also customize these models? Although I had originally planned that this would be the last post in this series, I am now planning on writing one more post on these models at some point. Stay tuned.
^ https://fascatcoaching.com/blogs/training-tips/how-i-invented-sweet-spot-training
https://fascatcoaching.com/blogs/training-tips/sweet-spot-training-with-dr-andy-coggan
* As I have previously blogged, I think the difference between Zone 4 and Zone 2 is greater than two-fold, but for the purposes of this illustration, it doesn’t matter, the principle is the same.
