The use of training zones has become ubiquitous at all levels of endurance training, and has even made its way into resistance training. While I cannot the usefulness of prescribing a zone for training, its overuse and over-valuation has led to a great deal of misinformation. A recent debate on Facebook regarding a training peaks article inspired me to put out some more thoughts on zones and their uses/misuses, as well as putting too much weight in any one magical zone. What follows is a paraphrased recap of the debate.
The question arose from a question of whether I agreed with Inigo SanMilan’s view about Zone 2, which is that endurance (i.e., faster than recovery) intensity where its not very hard and reliant on fat and carbohydrates, and is good building a “base”. My answer was NO for a few reasons, but mainly because the volume model presented cannot be taken to be the best simply because that’s what elite athletes do. I would be the first to admit that Dr. SanMilan and Dr. Lim both know more about Pro Tour level athletes than I do. However, I would also not train a Pro Tour rider like I would train a 50+ cyclists with less than 10 hrs/week to train. So then why do we assume what elite athletes do is best for semi-pro’s, as Damian Ruse likes to call them?
The major underlying problem is the ERROR by EXTRAPOLATION, which athletes used to accuse sports scientists of trying to apply studies done on average joes to athletes. Turns out the latter generally works better than the former. It is one reason I do not fully agree with Allen Lim’s opinion on hydration. He designed a drink for Garmin’s needs, which are nothing like my needs, or yours, or even that average US pro. Will you die or do poorly using Skratch Labs products? Doubtful. Likewise, if Allen Lim wanted me to follow his training methods for a year and he did all the work would I? Yup!
Regarding Zone 2 training, however, is actually far more complicated than just an opinion about pros vs joes. I’ve already posted at length about HIT and polarized training models. The empirical evidence to support this model for training, particularly for non-pro tour level athletes, more than Inigo’s model. Moreover, the zone 2 stuff smells too much like threshold training, which is nonsense, but LT training is just being rebranded and pushed. Polarized training is actually what most scientifically driven coaches and athletes are using, and it is supported by several papers by Paul LAURSEN; additional volume simply cannot make you faster, HIT is essential, and if I have only 8 hrs to train, spending more than 6 hrs in Zone 2 isn’t going to do sh!t more me!
Obviously, personal training history/success is difficult to argue against, and I strongly disagree that LT or lower training is the best way to meet your goals, unless your racing Ultra-type events. Any anecdotal reports of the value of LT training ignore that the concept was born out of blood doping and the largely disproven Conconi test (which DOES NOT work). Close scrutiny of the scientific literature (on athletes) at best is less effective than true HIT. Moreover, as Hamish Ferguson pointed out, its also a myth to think that most time trials and triathlons are power stable events; XTerra events are anything but!
A second argument is that research studies lack statistical power, so therefore are meaningless. This actually is not entirely true. While beyond the scope of this article (and I’m already off title), evaluating differences by p-values and confidence intervals alone is generally accepted to be a poor evaluative method. Batterham and Hopkins (2005) offered a new approach that has been adopted my many to make sense of small performance differences; remember, the difference between first and 9th in both the Tour de France and Olympic 100 m is typically less than 1%.
Bottom line 1: Zone 2 and actually LT blocks can be very effective at building sustained endurance, and if you have lot of training time, it makes sense to do training here, particularly interspersed throughout your periodization plan. The fact that polarized periodization appears highly effective, it does not and should not mean that every training block for the entire year is an 80/20% breakdown. There’s nothing wrong with doing a 3-4 week block of 50/40/10%. However, if you want that extra 10-20%, or you have minimal (<8 hrs/week), then a program built around HIT is going to be best.
The Zone Myth
Now, I started this whole post off with the suggestion that zones are not all that, and they kind of aren’t. The above discussion illustrates the problem with rating one zone better than others. When I reviewed Greg McMillan’s book I mentioned why I liked his approach to zones.
It takes what many coaches attempt to present as literal quantities, and turns zones in abstract qualities, or, training outcome objectives. Simply put, you train for endurance, stamina, speed, or sprint (power). Clean, easy and simple, these four training zones house numerous training possibilities and leave behind complicated made up energy systems or abilities; sorry, but 10 training zones is utter nonsense and are really just representing types of workouts.
Zones can and should represent qualities, not metabolic or mechanical quantities. Yes, you can do the latter, particularly for power zones, which are more precise, but never lose sight of the limitations of the zone which falls on a continuum that flows from day to day; it’s also another great way to use both HR and power together to get an overall training effect. The more numerous or specific a zone is, the less meaningful it probably is. Assuming you’re not sick or injured, being 10-20 W “out of your zone” is not always a reason to dump a workout. Live for the moment and TUNE IN, rather than TUNING OUT!