Question concerning 2x20 and HR

daveryanwyoming

Sure, as hard as you can while still completing the efforts and not so hard that you can't do more similar work later in your training week. IOW, there's no simple answer and it depends in part on your accumulated training load(CTL), your lifestyle and other demands like work and family, how well you tend to recover, etc.

The key as Alex points out is that you can try to find that cutting edge where you get the best theoretical return for your investment in training time or you can back off a little and get nearly all the training benefit without killing yourself physically or mentally. Working your 2x20s right up at 100-105% of FTP might give you the best results on paper, but will you be able to complete multiple efforts and can you physically or mentally do these several days a week all winter? Dropping those down to 90-95% of FTP makes it a lot less daunting and from a training adaptation standpoint you'll get the vast majority of the training benefits with a much better chance of sticking with the program all winter.

I tend to split the difference with one day a week where I try to push my 20 minute efforts (2x20s or 3x20s) right up to FTP. These are my mini time trial days where I try to see if I've improved and I do them early in my training week, usually on Tuesdays. Then I work down in intensity but up in duration for the remainder of the training week with perhaps 2x25 or 2x30 at 90-95% followed by something like 2x45 at 85-90% of FTP. I find this approach easier mentally than trying for full FTP efforts every time I train and was able to work a program like that for nearly 7 months last winter without frying myself. I introduced L5 work only towards the end of indoor training and saved the harder work for outdoors when the weather warmed up.

Anyway, there's no set answer to your question because you can't prescribe an exact intensity without also asking whether a rider will be able to stick to the program and continue doing it week in and week out for long enough to see real gains. This stuff only works if you do it hard enough, frequently enough and for long enough(both duration of individual repeats and over enough weeks or months) to get your body to adapt. Push the first condition and you might not be able to satisfy the latter two.

-Dave

ecandl

Thanks Dave, good as always. Nothing like my wife or kids coming out in the garage to ask me questions when I am testing FTP. I do have to go with the flow due to other demands.

I know that I can't do 105-100% very often without choosing to not get on the bike. I will focus on the 90-95% range and decrease intensity and increase duration as my week progresses. Now that I am getting more structure I hope to see my FTP move up over the next several months.

Ade Merckx

Use the Power Calculator. Number 5 http://www.cyclingpeakssoftware.com/power411/