What’s magic about the 8 minute training block?

Angels on the agenda today and other workouts use the 8 min block with repeats . What’s the specific training stimulus 8 , not 6 or ten at FTP just above and just below . Specific research or just more traditional?

AFAIK it’s based on anaerobic capacity, how much work you can do above threshold and how quickly you recover.

I believe this is referred to as W’ (W prime). It’s the amount of work you can do above threshold, and depletion duration varies based upon how far above threshold your effort is. Once depleted you’ll need a recovery interval.

Edit: A workout with six minute blocks would likely be considered a vo2max (MAP) workout, and 10 minute blocks would have to be closer to FTP or even below if there were multiple intervals, an endurance session.

Sirs Neal Henderson and Mac Cassin did a W’ analysis of all the Sufferfest workouts to ensure that they provided the correct stimulus, adjusting many of the workouts as a result.

This article might help
W' (W-Prime).


Thanks - good read . I’m trying to get a handle on why the 8 min block which is used quite a bit in Sufferfest , on
Location and no vids with a work rest ratio of 2:1. I figure Sir Neal did the math to set recovery segments at about 1/2 of work and recovery power about 50% FTP. But why 8 min ? How about 10 on 5off for same ratio. I am also assuming the ratio is standard based on efforts in the vids, but does 8 min peak the energy system and 10 min at same effort theoretically make it to too hard to recover in a reasonable time ? Most of these are around your FTP just a bit above the 20 min power, so is 8 x3 better than 10 x 2?

There are a number of workouts with longer durations in them, but those intervals aren’t typically over/unders.

For workouts with the suggested intervals, take a look at Defender with 10 minute intervals and Attacker with 6 minute ones.

I suppose this also calls for an experiment to see if 2x10 over/unders are feasible. Maybe try rewinding the last two minutes of each o/u on Ángels or another video you love, and see how it works out.

@Stevewvu Check out the FTP progressions in the NoVid section. Seems like 8 minutes is sort of mid ground for these types of intervals and you can see that repeating 10 minutes is seen as more challenging based on the workout descriptions.

The right training stimulus for an athlete will always vary based on specific strengths and weaknesses but as you can see from those workouts the variation comes from both the length of the intervals and also the number of sets of intervals.

1 Like