Building aerobic capacity is essential for most competitive cyclists since anaerobic threshold power (also known as lactate threshold or critical power) is the best single predictor of performance in road cycling races.
What can you do to increase your threshold power without spending more time on your training sessions?
The answer is interval training.
Probably not a big surprise, but many riders are not aware of the enormous benefits waiting for them when they start implementing interval training. Not just intervals as you are used to doing them. I talk about sharply targeted intervals designed to increase your threshold power.
1.Perform a Threshold Power Meter Test
I recommend you do a 20min all-out test to get a picture of your current threshold power. In theory, it would be even more precise to do a more extended test with a duration of 45-60minutes, but I don’t recommend it.
If you are the lucky owner of a professional power meter like SRM or PowerTap SL, it’s easy to read your average power output in the test. If you do the threshold on an exercise bike, it might be a little more challenging to calculate your score, but it’s still possible.
2.Plan Your Interval Training
When you know how many watts you managed to perform in the 20min maximum test, you can plan interval training on these values. The main reason to use a power meter in your cycling training is you get a better and more accurate picture of the physiological parameters you want to improve.
An old rule of thumb says that you get good at training. Using a power meter makes it easy to train exactly what you want to improve.
In this case, we would like to focus on threshold power, so we use our test result to plan the interval training. That means that if you hit an average power output of 276W in a 20min maximum test, your intervals could look like this:
3 x (8 + 4min) 275 / 140W
That means 8minutes work with a power output around 275W followed by 4minutes with active recovery around 140W. You shall repeat these intervals three times, giving a total of 24minutes with 275W and 12minutes with 140W.
3. Ride your wattage controlled intervals
Now you are ready to start your interval training. After a solid incremental warm-up, you are prepared for the interval session.
Try to maintain a power output as described, don’t go faster than your training plan tells you to (at least not in the first interval). Interval sessions like these can be ridden 2 to 3 times per week and used in various combinations with other intervals.
6 to 8 weeks later, you should go back to Step 1 to do another power meter threshold test. Then you can plan new intervals based on your new (and better!) threshold power.
Great post, I have a question, do you think I should alternate my interval training between two workouts like one day on the bike and the next training day on a treadmill? Could this help my threshold power or hinder it?
So if I do for example 6x(8+4) I would get 48 minutes at threshold but not as much fatigue to the body due to the 4 minute resting in between when compared to the 2×20 min thresholdinterval? Is it that simple?
Whats the difference between doing 2×20 and this, physiologicaly speaking?
By fatigue to the body I mean that the recovery is faster, but the time spent at threshold is the same as compared to doing 2x20min?
You are probably able to maintain a higher power output in the shorter intervals thus better training of your aerobic system. It’s difficult to say which workout will result in the best improvement. Most likely there isn’t much difference. Though, I would prefer the shorter intervals.
Greetings, I have been following your 16 hr. training log and on Tues, Wed, and Thurs. we have intervals and AT traing. What should the HR/effort be for the rest of each ride? Thanx so much for the advise and keep up the web page. I look forward to your ebook, Thanks Brian
Your instructions to get an estimated FTP are incorrect. To get a true FTP to use for training zones you should use 95% of a 20min max effort. Alternativley take the average pwr for a max effort 60min (25mile) time trial.
This is because a proportion of the 20min effort will be using anaerobic output which will cloud your true threshold output figures that shoud be used for training.
Hi Andy,
Thanks for providing your knowledge about functional threshold power. Just to correct you: I don’t give instructions regarding functional threshold power.
You’re right that using 95% of your 20min test gives a better estimate of your functional threshold power. Though, as I also write, performing a longer test would give a more precise picture of your current threshold power than the 20min test would.
But from a practical point of view, evaluating your aerobic performance with a 20minutes test will work fine for most people.
Kind regards,
Jesper
Hi Jesper,
think we’ll have to agree to disagree. From a practical point of view there’s a big difference in most mortals 20min power to their 60min power. 60min being a truer reflection of FTP.
As an example my 60min avg is 254w where as my 20min is 277w. 23watts is a big difference, especially when used 2-3 times a week in a 6-8week plan as suggested.
So in my case, 277w intervals would be closer to a low V02Max session rather than FTP, which isnt an ideal zone to target to increase FTP.
Andy,
Please notice what I write in my article: “I recommend you do a 20min all-out test to get a picture of your current threshold power. In theory, it would be even more precise to do a longer test with a duration of 45-60minutes”
I guess that is close to what you call “60min being a truer reflection of FTP.” 🙂
Though, I would still recommend intervals based on a 20min test as a good way because that is one (out of many ways) to improve threshold power.
You can find more about my view on how to increase threshold power here:
https://www.training4cyclists.com/threshold-power/
No problem Jesper, I’m just being a bit fussy 🙂 I know it’s not an exact science, even though we would all like it to be. Personally I struggle to hold 90% for 8mins…
Great link by the way.. Cheers Andy.
I’m actually glad that you challenge my views on training. Keep commenting, please 🙂
do a 30min test find the average and add 5% and do intervals recommended. simples
helpful post, thanks!
Can I perform the same intervals using heart rate as a metric instead of power output? I’m not sure how to measure my wattage on my stationary bike trainer without purchasing additional equipment.
for people who have not SRM nor POWER TAP,wich gear to use for those kind of intervals,for an semi pro rider as example?
Hi
Is there a difference between riding on the road and riding a turbo. I can manage 300 watts in 20 minutes on the road but only 260 watts when I set up on the turbo. Why is that?