Sprints for Triathlon?

I received an email from one of my triathletes about the purpose of some recent cycling workouts. In particular, I have been prescribing 30 second all out sprints with generous, 3:30-4:30 minute recovery (most everyone would argue with the generous part).  Many of my athletes got a huge dose of these that eventually moved into Billat style intervals of 30 secs one/30 secs off.

For the most part everyone who has been doing these I have transitioned them into something a bit more traditional/specific to the sport. I’ve found these types of workouts really do help jump start the engine and build fitness quickly. It is, however, pretty critical to pay attention to the fatigue levels since the intensity is generally way higher than most triathletes are used to.

The email is cut and pasted below:

Athlete Question:

I’m just curious from a coaching perspective what these are intended to accomplish (aside from them pushing me to the brink)?  I would assume anaerobic threshold and thus FTP threshold, but not sure.

Answer:

Really, I just like torturing people and making them ride with a bucket beside their bike.

Basically, I structure everything from least specific to most specific with regards to training load. 30 sec sprints and 30/30 intervals are pretty bike racing specific but not very tri race specific. However, they work really well to jump start the engine. Plus it is just something that most multisport athletes lack. Being able to cope with those short bouts comes in handy if you run into a steep hill on course and just need to get over it. Here is some research on it:

http://www.researchgate.net/publication/12966624_Effects_of_different_interval-training_programs_on_cycling_time-trial_performance

The 30/30 intervals are attributed Veronique Billat and are often call Billat intervals. Very similar to Tabata intervals:

http://coachsci.sdsu.edu/csa/vol71/billat3.htm

Longer intervals work as well, but I generally save the longer stuff for closer to the specific race prep phase. Basically we’ll go from this to 4 minute VO2 out to 8 minutes at >100% of Threshold. As we get inside the last month to six weeks or so leading into A races will get into race pace intervals which will seem really easy at that point.