Decrease in 2nd 20 minute interval?

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If you can't maintain the same power in the second interval as the first, should you decrease the power of the first to allow for equal intervals? I recently started 2x20s with substantial initial improvement, but have recently been unable to match the power from the first to second interval. Any advice on this? Is it better to keep it consistent or does it matter? There is probably a 20-30w difference in power between the two.

If you can't maintain the same power in the second interval as the first, should you decrease the power of the first to allow for equal intervals? I recently started 2x20s with substantial initial improvement, but have recently been unable to match the power from the first to second interval. Any advice on this? Is it better to keep it consistent or does it matter? There is probably a 20-30w difference in power between the two.Not sure if I'm getting this right. Had you previously been able to sustain the new higher power for the 2nd 20min interval but now you can't?

I'd suppose one gets the benefits when rides in the target zone (or were they called levels...). But, I have found it easier to track the development by riding the same power on both intervals. Eg if i ride 2*20 min on 250 W, I don't have to speculate wether I'd take the average or normalized power which would be case with eg 260 + 230 W intervals.

If you can't maintain the same power in the second interval as the first, should you decrease the power of the first to allow for equal intervals? I recently started 2x20s with substantial initial improvement, but have recently been unable to match the power from the first to second interval. Any advice on this? Is it better to keep it consistent or does it matter? There is probably a 20-30w difference in power between the two.

You are getting carried away and doing the first interval too hard. Either consciously back off on the first one, or else do 1x40 instead to keep yourself under control.

If you can't maintain the same power in the second interval as the first, should you decrease the power of the first to allow for equal intervals? I recently started 2x20s with substantial initial improvement, but have recently been unable to match the power from the first to second interval. Any advice on this? Is it better to keep it consistent or does it matter? There is probably a 20-30w difference in power between the two.

The second 20 min interval is always going to be mildly painful but if you have to drop your power down 20-30 watts to finish it you're going out too hard on the first. Try splitting the difference. Go out on the first interval 15 watts less. You may also want to experiment with your recovery time/days. It could be that you're not recovering enough to do 2X20 at optimum power.

All this said, it probably doesn't make a big difference to your training progress if your first interval is a little too strong and your second a little too weak. The idea is to push your limit for a significant period of time. The precise numbers aren't that important.

Not sure if I'm getting this right. Had you previously been able to sustain the new higher power for the 2nd 20min interval but now you can't?
I think the first time I was close but no, I couldn't. The subsequent times have been even harder on the second interval.

You are getting carried away and doing the first interval too hard. Either consciously back off on the first one, or else do 1x40 instead to keep yourself under control.
I think you are right! The jump in power on the first interval is new for me. I probably just need to back off on the first one.

The second 20 min interval is always going to be mildly painful but if you have to drop your power down 20-30 watts to finish it you're going out too hard on the first. Try splitting the difference. Go out on the first interval 15 watts less. You may also want to experiment with your recovery time/days. It could be that you're not recovering enough to do 2X20 at optimum power.

I agree and will try and do this.

All this said, it probably doesn't make a big difference to your training progress if your first interval is a little too strong and your second a little too weak. The idea is to push your limit for a significant period of time. The precise numbers aren't that important.
I guess this was my big question. Will it adversely affect my performance and improvement to have uneven intervals? I guess you are saying no. That's good, but I think I may drop the first one a bit anyway. I may enjoy the intervals a little more if I do!:D

Thanks everyone for all your responses!

You may need to focus on base training. 40 minutes at or near FT requires some training foundation.

I guess this was my big question. Will it adversely affect my performance and improvement to have uneven intervals? I guess you are saying no. That's good, but I think I may drop the first one a bit anyway. I may enjoy the intervals a little more if I do!:D

Thanks everyone for all your responses!
It's not substantially worse training unless the second one is much lower. I think Andy Coggan's book gives a guideline -- something like if the second interval is more than 10 watts lower then ease up a bit on the first (but I can't remember the exact rule of thumb). These things are hard to predict though. Sometimes I'm on a good day and actually go 10 watts harder on the second!

Lanier

You may need to focus on base training. 40 minutes at or near FT requires some training foundation.
That may be so. Although I kind of wonder if I am doing too many hard efforts. I am doing 5 days of training with 2 2x20s with an easy day in between. I do longer rides on the weekends which include a lot of climbing (for me). These climbs tend to be a little below 2x20 intensity, with a similar duration.(20-30 minutes) There are maybe three climbs like this on these rides. So I don't know, when I started to see the second interval drop, It crossed my mind I may be overdoing it.

If you can't maintain the same power in the second interval as the first, should you decrease the power of the first to allow for equal intervals? I recently started 2x20s with substantial initial improvement, but have recently been unable to match the power from the first to second interval. Any advice on this? Is it better to keep it consistent or does it matter? There is probably a 20-30w difference in power between the two.If it doesn't happen regularly you could simply be tired. Just yesterday I did a 1 hr non-stop SST session. Started out at L3 gradually ramping up, and the last 15 min was at FTP. I felt great! Today I went for 2 x 20 at 95% FTP, but the first 20 min block felt so hard that I decided to forgo the second completely. All it means is that I should've rested better after yesterday.

other options would be to use a longer recovery period. i use 10min instead of the standard 5min. also you may want to use shorter intervals i.e. 4x10 rather than 2x20. both these alternative are less efficient in terms of time but you still end up with the same amount of time at intensity x and if at the end of the day you spend more time at that higher intensity you are farther ahead reguardless of the recovery time.

other options would be to use a longer recovery period. i use 10min instead of the standard 5min. also you may want to use shorter intervals i.e. 4x10 rather than 2x20. both these alternative are less efficient in terms of time but you still end up with the same amount of time at intensity x and if at the end of the day you spend more time at that higher intensity you are farther ahead reguardless of the recovery time.
hmmm ... I'm not sure I would suggest any of those things for core threshold training. Go a little further and you're into simply riding 'chunks' at threshold as some have espoused, i.e. w/o much regard for the interval duration.

I figure one will get better long-term results by dropping the power a little to complete a proper 2x20 or even better 1x40. The only reason to break 'em up is mental anyhow ... IIRC from Dr. Coggan's original writings.

Now if you're peaking for a short TT or a road race in which there are plenty of 10-min climbs, that's another matter altogether. I'm talking core/long-term threshold training.

hmmm ... I'm not sure I would suggest any of those things for core threshold training. Go a little further and you're into simply riding 'chunks' at threshold as some have espoused, i.e. w/o much regard for the interval duration.

I figure one will get better long-term results by dropping the power a little to complete a proper 2x20 or even better 1x40. The only reason to break 'em up is mental anyhow ... IIRC from Dr. Coggan's original writings.

Now if you're peaking for a short TT or a road race in which there are plenty of 10-min climbs, that's another matter altogether. I'm talking core/long-term threshold training.I'm with rmur on this one.

If you think 4x10 is better than 2x20, take a look at the normalized power for the two entire efforts from the start of the first interval to the end of the last including rest periods in between. If you gave both types of workouts an honest effort and the recovery breaks aren't too long, the NP will probably come out to be about the same. If the recovery breaks in the 4x10 are long, that will push the overall duration longer and put you farther along on the duration curve so the NP could be lower.

Steve