Im doing my 1st 200% 20 second sprints today on the Wahoo Kickr. Should I do these in ERG or do them in Resistance?
I did notice a similar question that said switch to resistance for the sprints, but I dont know how to do that in terms of timing and all that.
It’s going to take a little bit to figure out what resistance % to use but I think you should do it in resistance. I have found that on my Tacx neo I need 18% and a big ring shift to get me there.
Holding steady wattage in erg for that sprint is going to be pretty hard to do and doesn’t really matter. ERG mode on a sprint has a tendency to put you in a death spiral if you start to waver early in the sprint, and the ERG adjustments will drag you down to a stop. With resistance your watts will drop but you’ll still be able to pedal and attempt to push the watts up, and then you can “coast” a little after the interval
Either mode can work. Some people prefer one or the other. The only way to know is to test for yourself.
Resistance takes some experimentation to find the right gearing and cadence.
ERG works well for these efforts in my experience.
I did not want to start ANOTHER thread regarding sprinting in ERG, but my question is similar.
The sprint workouts are topped at like 180% of FTP(342watts). In ERG i can easily hold the interval. But my sprint wattages are usually like 600+ in Zwift and like to train more on high wattages. My question is if it’s ok to go way over (using resistance mode) to perform these intervals?
Yes it is.
The true sprint workouts are at 225% FTP.
The workout descriptions say:
Each sprint is intended to be a maximal effort, so adjust the Intensity appropriately in order to barely finish each 30-second effort.
The progression is Birling → Detling → Charing → Titsey → Rowdow → Stangate. As you get fitter, you progress to the next workout which adds one interval.
My off-the-couch max sprint power was about the same as it is now with a 50+% FTP increase. The difference is the ability to complete 4 intervals vs 9, and hanging on for the full 30 seconds on every sprint, not crapping out at 20-25 seconds in.
So i just had my first resistance SIT. Had to play a bit with the resistant % and experienced this:
I run an 8-speed 50-34 front 11-32 back. I set my resistance to 15% cause that felt the best for my recovery intervals, but for my sprints i will overspin. Tried again with 30% resistance, where i need to be in small chainring in front to order to get my 60-70watts recovery, but i will have to gear up a lot for my sprints where i still overspin a little bit. Not sure if nesscary, but see link to my workout.
Interval 1 and 4 was seated, 2 and 3 was standing. And 5 was standing and seating.
Since the intervals are intended to my maximal effort, i’d assume i should do this standing?
And is there a way to play more with the resistance without gearing up so much or is it cause of my 8-speed cassette?
I spend the first 20 seconds seated and the last 10 seconds standing.
It really doesn’t make a difference either way as long as your gassed.
I do it in erg.
Yes, i understand ERG is easier, but not when its topping me off at 411 watts. Each interval i was eay above 550 watts
Its not due to the 8-speed. Just the gear ratios. Just jump front rings?
Not quite sure what you mean with that?
Above you say you’re in the small ring during workouts? Just jump up to the big front?
Or are you maxing out in your highest gear?
Ahhh yes, but only for the recovery interval otherwise i can’t keep watts low. But when sprinting i have to gear up a lot(small to front and in the back also)
I did that but got noise complaints so I’m consciously in the wee ring.
Thats just the nature of using resistance rather than ERG. Nothing to do with being 8 speed. Just use ERG 
I dont like how my trainer holds power in ERG for short intervals. It seems slow to react sometimes hangs (keeps the resistance high during recoveries) or as I sprint it loses all resistance too soon and I’m spinning like crazy. I’d find that sudden erratic-ness would strain things in my legs so I do short high intensity stuff in resistance mode. Ive also read stuff about VO2max being a state of oxygen maximum and not a power target (for some folk a power target might be to low and they would be better to spin to the max). Watts Doc #23: Training Your VO2max, and Why Not Rønnestad 30/15 Intervals - Empirical Cycling However, if it works better for you in ERG mode though IMO there’s no harm in that. Just do what suits.