Winter bike training - 20 x 2's and Functional Threshold Power

I started my Winter training in the pain cave last night and, since I have a number of friends who have expressed an interest in how I train over the Winter, I thought I'd write a blog about it.

One thing became readily apparent last night: I've lost a lot of fitness over the 7 weeks since the end of last year's season. Last night's workout was surprisingly hard.

Here is the workout:
20' x 2

10 warmup
20 threshold
5 recovery interval
20 threshold
5 cooldown
60 TOTAL

The 20 minute interval is the mainstay of those who train using a power meter. Visit the Google Wattage Group (you may have to apply for membership) and you'll soon discover this for yourself. The entire workout is only an hour long. The two 20 minute intervals are the main set. These should be done, initially, as hard as you can manage for both intervals. That is, you try and pace yourself so that you are able to finish the second 20 minute interval at the same power you started the first 20 minute interval. When starting out, there is obviously some trial and error involved in this but after a few sesssions, you'll soon figure it out, whether using a power meter or going by heart rate.

Ideally, you would use a power meter to gauge your effort. But you can still reap the benefits in muscle fibre recruitment using a heart rate monitor. During the workout itself, try and keep your power output within a 10-20 watt range. Using a heart rate monitor, you'll probably fluctuate within a 10 beats per minute (bpm) range. For my first workout of the season, last night, my first interval averaged 13 watts higher than my second interval and my average heart rate looked to be about 5 bpm lower but dropped a little more towards the end of the second interval. (The effects of fatigue were quite noticeable last night. The average of my second 20 minute interval was 43 watts lower than what I was able to complete for an entire 60 minute interval by the end of last January and a 15% drop in FTP).

One nice thing about using the 20' x 2 as a workout is that it is so ubiquitous within the power meter community that it has been established as a test protocol for measuring one's functional threshold power (FTP). One's functional threshold is defined as the average watts one can produce under ideal conditions over a one hour interval. Ideal conditions means you should be fresh (i.e. tapered) and able to go all out for the one hour period. The problem using this measure is that it's rarely practical to do the test. (The only time I've been done it myself was last January). Instead, the 20' x 2 workout can serve as a proxy to an all out one hour test. To estimate your FTP using the 20' x 2 protocol, you take the average of the two 20' intervals and multiply by a factor of 0.95. This will get you in the ballpark of your FTP. What I have found is that the multiplication factor should be lower (i.e. in the 90-95 % range) for well trained athletes and higher (in the 95-100 % range) for those either just starting out or, as in my case, de-trained.

So what do I do with FTP once it's been calculated.?

The importance of knowing one's FTP is in determining one's training levels (follow the link for more information on Andrew Coggan's training levels). In order to develop more power on the bike, one needs to get as much time in L4 (90-100% of FTP) as feasible. However, it's determined that a more optimal training range is within what's been termed the sweet spot. The sweet spot ranges from about 85-100% of FTP. What people have found is that you can gain close to the same benefit by training a bit lower than L4 (i.e. high L3 or Tempo) at less metabolic cost. The advantage of this is that you can do more frequent quality workouts because they don't tire you out as much as a pure L4 workout would.

My Winter bike training plan will start at three 20' x 2 bike sessions per week for probably the first six at least. After that, I'll re-evaluate my program and determine how to add more training stimulus. One thing that you should keep in mind when designing your own training program is that my main focus is on running this Winter. I'm currently running every day. So whereas I might be doing only 3 "spins" per week, if bike sessions are your only training, you might want to consider adding an extra day or two depending on what your goals are, your energy levels, and time constraints.

In future blogs, I'll get more specific about my training schedule and my reasoning behind each workout. I'll also post some tips on how I get through these trainer workouts. I'll also go over the WKO+ software and show how the Performance Manager can be used to ensure your training program has the right amount of progressive overload.