I’m trying to progress to longer threshold intervals (~ 20 min) to better mimics the climbs in my goal MTB race.
Assuming comparable RPE/HR, is there a physiologic reason why shorter threshold intervals (4X8min + 2 min rest) are preferred, compared to 2 X 16min or 1 X 32 min? Could the more frequent rest periods help train the body to clear/utilize the lactate better? Or maybe the shorter intervals are better to limit the stress/fatigue while providing the same training adaptation?
This is a great question.
I’ve seen it suggested by other Podcaster/Coaches, that you should train based on your TTE (time to exhaustion). You hold your FTP for as long as you can, say 40 minutes. Then perform intervals at 4x 10 min, progressing to 4x12, 3x15, 2x20 etc…
Does this idea have merit?
Great question @robertehall1. I agree with @shawnfife on the TTE metric and think it gives you a great starting point to build a progression if you have good data in the model.
In terms of a physiological reason for shorter vs. longer intervals, I look at the shorter ones as your starting point where the load is more manageable - to your point, limiting the strain on the body while providing a progressive overload. As we know, those aerobic adaptations take time. 2x16 or 1x32, for example, are pretty long and can take it out of you mentally and physically, so I see those types of efforts as very important, but also to be approached when you are ready for them. It sounds like you are looking to do this progressively anyway, so I think you’re on the right track.
(To your suggestion on the physiological reasons, I just re-started some 5x5 intervals recently after a long break following Breck Epic, and realized that because of the HR response by the end, there was no way I should do longer intervals at this time)
As an example, in my pre-covid years coaching indoor cycling, I would always do a progression over the winter to move from technique (couple weeks) to tempo (a few weeks) to sub-LT shorter intervals (few more weeks) and then we would finish with the Sufferfest Hell Hath No Fury, which is a 2x20 workout. (the whole progression would take around 3 months to get there) By itself, or too early in the progression, the majority of riders would fail on that workout, and it would be demoralizing for them. But with a build that started with shorter intervals, they would come into those longer ones feeling ready, and they would actually accomplish the whole session. This worked out well for the riders around Boulder because we have plenty of 20+ minute climbs available, so I think your thought on progressing toward longer intervals to mimic the climbs in your MTB race definitely has merit.
Thanks @ryan! I think when I asked the question early in the season I was thinking about intervals with more specificity to my race. Having a bit more experience now, and from listening to you guys, I can see that shorter intervals (5-8 min) with short rest periods (1-2 min) done at higher quality will likely lead to a stronger stimulus for adaptation. For next year I’ll stick with that approach for intervals in the base and build phases. I’ll target the specificity later in the season with some longer strava segments and god willing some actual racing!
Why do you want to mimic the race in your training?
I ask, because it implies that your training will cause the same stress to your body as the race would do. That will lead to longer recovery → less training volume → lower aerobic capacity → lower race performance. I think you want to achieve the opposite.
If you want to improve your performance on the climbs, you can:
None of these three points include ‘longer high intensity intervals’.
One more point:
@kjeldbontenbal I agree with all of your points. I did weights, base miles, and a bit of VO2 work last year but I think I can do more and better organized next year. I do feel that some race specificity is good for my confidence and technical skills (MTB races). I think I’ll leave the specificity to some on trail work next spring and summer, rather than longer intervals on the trainer.
TTE can be a good starting place for this type of work I would agree as long you have solid data in the software.
Having said that if you were going to do intervals slightly below threshold, I would expect that most could do one more interval past their TTE. As an example if the TTE was 34 minutes, the athlete could likely do 4x 10m or maybe a little longer if the intervals are slightly below threshold, which is how I would prescribe them.
If you are training right at threshold this might be a different story.
@steveneal my goal event which got cancelled until next year, is a six day MTB stage race, average of ~1300 m elevation gain per day, about 2.5 hr duration per stage. Each stage would typically have multiple 30+ min climbs with the longest being about 60 min. I think I’ve learned from this resource that it’s likely better to “built the engine” and let the body figure out the racing. I did some longer strava segment hunting this summer which would reflect high sweet spot zone. This maybe isn’t perfect for the polarized training model, but I found it useful for confidence and developing bike skills while riding hard on technical trails.
@robertehall1 which stage race actually?
Yes with it being a stage race, those durations each day and those lengths of climbs, you won’t be climbing at threshold.
Building a strong tempo engine, nailing nutrition and pacing, and getting comfortable descending (lots of time to be made here and energy saved).
I have always had success with my clients at SingleTrack 5, BCbikerace, Pisgah Stage Race by having a really solid tempo ability, and amazing recovery. I do a lot of tempo work with them, building up to multiple 90-120m tempo sessions 2-3 times per week.
The other thing that is very important is to ride your mountain bike on similar terrain. 250w normalized power on gravel is very different from the same of Rooty, slightly wet Mtb terrain.
Love working towards a stage race! so fun.
Can’t wait til next year! https://www.singletrack6.com.
Yes I got lots of single track riding in this year. A couple good overreach MTB trips and me and some buddies did some “pretend” racing on the courses in place of the real event.
Awesome it is an amazing event.
I will be living in Revelstoke, BC starting December of this year so the race will now be in my new back yard 
Maybe I should run some MTB camps with testing in the future!
You will have a great time, excellent race if you haven’t done it before.
What is your current Threshold and weight? I might have athletes that are in similar place and cold show you some files from the race and how they did.
Just checked my guys were 4, 5, 10, 11 in 50plus and then another 40plus in BCBR 2nd place so I should have a good range of data to show power output, they all have powermeters.
@steveneal, Reve is sweet! I’d be interested in training camps. I’m in Calgary. I’m 60 kg and not sure of an accurate FTP. I haven’t tested since winter (245W). I trained/rode a lot this spring and summer so maybe 250W?
Sounds like a very tough event! #respect
Now that we know the target race I have one more advice: buy lots of M&Ms to:
A) recover between races
B) draw attention away from these awful climbs
C) throw at the competition when the legs start hurting.
@robertehall1 here is a quick summary of two stages. Athlete A 4th place, Athlete B 11th place.
I just looked at the climbing, Norm Power, NP / kg, time.
I also look at VAM or how fast they climb, and also have the same formula but for downhill, this helps me analyze how the climbing and descending changes over the course of the stage and on different types of terrain.
