How hard should I pedal during Red Intervals?


I am a Enduro, and occasional DH racer and have been slacking on training like I should this season.  I am trying to finish out strong and get in a solid 7 weeks of training before my last race at the end of the September and am working hard on the Prepare to Pin It program, building on a base of PUTB done through winter and early spring.  My question(s) are regarding power and gearing for the red intervals:

Should we be doing all out sprints?  In the book it states 120-140% or something along those lines, but I’m putting out north of 700 W @ an FTP of 278 W, which is over 200%.  Like you’ve said, this says a lot about my endurance, plus I’m a pretty big guy (190ish lbs, a hair shy over 6’), but I wasn’t sure if I am going to hard.  To me I’ve never gone below 90% in a race so I don’t know why I would do it in a training session.

In the book, it states when power drops by 10% the session is over.  Is this over the course of the entire sprint session or during easy “set”.  My first set of 3 x 20 sec I was in the 650-700 W range, second set was 600-650 W, but the third I went from about 600 W to just below 500 W, which is over a 10% drop.  This was my sign I was toast, but if I follow the rules of 10% over the workout I wouldn’t have even made it through my second set.

Lastly, is it normal to not to be shifting during the middle of these sprints?  I start out with a somewhat challenging gear but I’m spinning too quickly to feel like I’m delivering good power pretty quickly and shift 2ish times during each sprint.

Thanks for the great programming, both on skills and fitness.  My riding has improved immensely over the last 2 years despite being pretty inconsistent about training.

Brian Rowbotham

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Thanks for reaching out.

Red Intervals are the cornerstone of the Prepare to Pin It training program. You work very hard for a short time, partially recover then repeat. A common protocol is 30 seconds on, 30 seconds off x 3 sets of 5. This is so tough very few people are willing to do it! But it helps you maintain higher power for longer, and it helps you repeat hard efforts.


Maintain as much power as you can for the duration of all of the intervals. You and I have similar numbers: moderate FTP but earth-shattering sprint power.

It sounds like you might be going too hard to get the full benefits of this workout.

I generally do not shift. Peak power often happens around 120 rpm. Try to accelerate to that level in one gear, at your target power number, and hang on.

Red intervals train high-level power and repeatability, which is handy for DH and enduro. Figure out what your achievable number is (maybe around 600 watts), then raise it over time or do longer intervals with less rest.

When it’s time for peak sprint power, go as hard as you freakin’ can!

I hope that helps,


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