Intervals, Part 1

Assuming you are now in your Build period of training with fewer than 12 weeks until your first A-priority race, now is probably the time to focus on interval training. I want to get into more detail on this topic in the coming days, but for now I’m just posting a quicky to make a general case for intervals. When I have time I’ll write about the types of intervals and their benefits relative to the typical events for which athletes train.

There have been many studies done on intervals. I’ll touch on some in the following parts of this series. One of the best reviews of the scientific literature on the topic came from Laursen and Jenkins at the University of Queensland in Australia (Laursen, P.B. & D.G. Jenkins. 2002. The scientific basis for high-intensity programmes and maximizing performance in highly trained endurance athletes. Sports Med 32(1):53-73). To quote from the study:

"Increased volume for highly trained athletes does not appear to further enhance endurance performance or associated physiological variables. For athletes who are already trained, improvements in endurance can be achieved only through high-intensity interval training."

This is a point I make repeatedly in this blog: the key to success for advanced athletes is intensity—not volume. If you want to go fast you must train fast. How many miles, kilometers, or meters you accumulate in each of the last 12 weeks before your event have much less impact on your performance on race day. If you’re going to make a mistake make it on the side of too little volume—not too little race-specific intensity.

The study’s authors go on to say that the improvements resulting from intervals are probably the result of increased muscle buffering capacity. This has to do with the body’s ability to absorb and remove the acid that accumulates in the muscles when the intensity is near or above lactate threshold.

They also indicate that the research has shown benefits for runners who did intervals at their velocity at VO2max (this is roughly 1-mile race pace). This is an interesting concept that has been known for at least 10 years now. But, they point out, supramaximal sprints by cyclists may be just as effective, or even more so, than doing intervals at power at VO2max (the equivalent of a runner’s velocity at VO2max). I’ll come back to both of these types of intervals in a subsequent post.

Comments

[Jez]

Hi Joe
Does this principle apply through all triathlon distances up to IM? If it applies to IM, would supramaximal sprint intervals be appropriate? I'm training for Kona this year using your books "Going Long" and "Your Best Triathlon". It feels a bit counter-intuitive to back off the volume.
All the best
Jez

[Joe Friel]

Jez--I'm going to get into such stuff later on. But to answer your question, in the build period training needs to become increasingly racelike. If not doing supramax sprints in an IM then they have little or no place in build.

[Håkan Myhre]

Thanks a lot Joe!
I'm a beginner triathlete following your techings from your book and your blogg. So far i do not need a trainer but in future i might need a trainer to be able to finish an IM. Or do i really need a trainer?
Im 29 years old and i used to be a singlesculler.
All the best
Håkan Myhre

[Chris Livingstone]

Hi Joe,

"Training Bible" describes "Threshold" workouts consisting of steady afforts at threshold pace e.g. 20 min continuous zone 4-5a. I find these to be EXCELLENT workouts for simulating race effort. "Your Best Triathlon" doesn't seem to use these workouts: threshold work seems to be all done thru intervals. Does this reflect new research? Are there types of athletes that should do threshold work as a single long repeat instead of intervals? Perhaps you could comment on continuous threshold work vs. interval threshold work in this series of posts.

Thanks,
Chris

[Joe Friel]

Chris--If it works for you then keep doing it regardless of what any books say, including mine.

[Alpinestyle]

Thanks! Do you have any opinion of recovery time (between supra-max intervals) to achieve the effects of "increased acid buffeting?" the Queensland study recommends quite long rest intervals (4.5 minutes), though I've read elsewhere (your book?) that shorter rest intervals are better to evoke this response. Perhaps this is a subject you'll touch on more in a future post? At any rate, thanks again for the great posts!

[Marc Feldman]

Joe,

I am very interested in this topic as I'm about to enter an IM build phase. Apologies in advance if you plan to address this later.

You say that intervals are key. But as you indicate in your books, IM race pace is Zone 2 at best. Long rides and runs will have to be at this race pace. So is there any room for Zone 3 or higher intervals in an IM build? Thanks.

Marc

[Joe Friel]

Marc--I'll comment on this.

[Joe Friel]

Alpinestyle--thanks. I'll get into types of intervals and their recoveries later in this series.