30/30 Intervals Revisited
Tuesday, February 15, 2011 at 07:10PM 
A couple of years ago, Mark Twight from Gym Jones introduced me to the 30/30 interval workout. Go hard for 30 seconds, go easy for 30 seconds. Repeat. Or so I thought. Although I came to really like this workout, it turns out that I really did not understand the concept and performed them incorrectly. It's no wonder that I liked them as much as I did. Going really easy during the rest interval allows for decent recovery and makes you feel pretty damn strong during the work bouts. I don't think performing them in this fashion is a complete waste of time but, as you'll see, performing them correctly is a different beast.
In order to get fitter and faster we need to do the work. As I have recently discussed, much of this work can be done at relatively low intensities. This kind of zone 1/2 training, while time consuming, is not particularly painful. However, somewhere around 10% of our total training volume needs to consist of the less pleasant, high-intensity, threshold and VO2 max intervals. This is the stress, when judiciously applied in the training schedule, that seriously ups our game.
The problem with these hard intervals is that they produce significant amounts of lactate. This creates an acidic environment within the muscle cell. To a degree, this kind of physiologic stress produces adaptations that help us race better. But many sport scientists agree that too much of this acid exposure damages and, ultimately, down regulates our aerobic machinery. Not good. So, how do we get the good stuff without too much of the bad stuff? Well, the 30/30 interval set attempts to do just that.
The idea here is to work at or slightly above threshold intensity. A lactate threshold test performed in a lab is the most accurate way to determine at what heart rate this occurs. This is a critical effort level. Doing so for 30 seconds is just long enough to produce the acid environment we are looking for but the effort is stopped before it gets out of hand. Now the important part. During the so-called rest interval, the intensity should be high enough to maintain threshold heart rate but not so high that acid accumulation continues. I find that if I overshoot my anaerobic threshold (AT) by a beat or two during the work bout, my heart rate drop during the rest phase can be managed with intensity titration, keeping within a few beats of threshold. On a steep slope, this is easy to do but on flatter terrain the demand is low enough that I really have to kick up the pace to keep my HR where I want it. With the drop in power output lactate levels are kept in check while the overall stimulus is adequate to produce the adaptation we're looking for. These can be continued for 10 to 30 minutes depending on your motivation. Certainly, you could simply do 10-30 minutes of sustained threshold effort(s), and you probably should from time to time, but doing them week in and week out may not be the best way to apply threshold training in your schedule due to the acid burden and subsequent stress that comes with it.
How much is too much? No one really knows. What they do know is that subjecting athletes to more than two high intensity training sessions per week for more than a few weeks will lead to signs and symptoms of over reaching in many individuals. It's unclear why this threshold of three is so critical but it seems to be and athletes have been getting stronger and faster on 2 x/week intensity training for decades.
So, if I led you astray with my previous interpretation of the 30/30 interval, I apologize. I must also apologize in advance for subjecting you to this corrected version. It's not that fun anymore. It also requires more discipline than the other version since you must pay attention to heart rate during the "recovery" phase and keep it at the appropriate level. But why should it be any other way? As Mr. Twight wrote a few years ago, there's no such thing as a free lunch when it comes to training. And if you don't know what I mean I encourage you to re-visit his treatise on the subject, TNSTAAFL. - Brian
Reader Comments (4)
Brian,
Could you please provide the original study in which your post is based? I read an article featuring a structured farlek session, developed by French researcher Veronique Billet, which requires running 30 seconds at Max VO2 pace followed by 30 seconds of running at 50 percent velocity max VO2 pace. Max VO2 training is different than lactate threshold training. I would like more detail on how you arrived at your conclusion.
Thanks so much!
Jeff,
Sorry I came to your question late. I don't actually get notified when comments come in. I always forget to check that little box for notification.
Anyway, your question is a good one and, unfortunately, I don't have a detailed reference for you to justify my suggestions. This workout comes from several discussions I have had with Mark Twight at Gym Jones. He, in turn, may have gotten this from his own, rather extensive reading or from Max Testa, a respected cycling coach and sports doctor. Max comes out of the well-known Mapei Center in Italy.
Honestly, it's probably difficult to really "prove" such training protocols. Rather, they are based on sound science and a great deal of anecdotal evidence from coaches world wide.
That said, there may be a paper out there discussing it but I have not looked for it nor read it. The protocol simply makes sense to me and I passed it on to those who read this blog. Caveat Emptor, indeed.
Credit where credit is due -- the 30/30 (and in earlier and later stages of training) the 15/15 and 60/60 comes from research by Veronique Billat, see http://www.billat.net/ for a whole pile of research papers.
Like all workouts, 30/30's are meant to supplement (not replace) a regime of lower-intensity aerobic/endurance training, so I would question their use within a Gym Jones regimen (which is essentially a derivative of a Crossfit plan) -- more focussed on power.
I should be clear that although I referenced Gym Jones above, the workouts described have little to do with any Gym Jones "regimen". Actually, having trained there and knowing Mark for several years now, I would be hesitant to put his programs into any "box". True, he uses his share of hybrid training techniques for many of his athletes but certainly does not limit himself to them.
Mark's agreement about the utility of the efforts referenced above is in the context of a more traditional endurance training program. I suggest you read "TNSTAAFL" to get the whole picture from Mark's perspective.
Thanks for reading.