Wednesday, September 30, 2009

Why didn't I think of that?

Thursday, September 10, 2009

Three Years of Tuesday Worlds: AP vs NP

I've had some discussions with a teammate recently regarding Average Power (AP) vs Normalized Power (NP). Although the data shows that for most time intervals my maximum average power hasn't changed drastically, I posed to him that I believe I can repeat the hard efforts more frequently in race-type situations. He responded that "it's probably just NP busters messing up your data due to different types of interval sessions you're doing this year." I thought he might be right, so I've developed a way to check.

I wanted a way to compare apples to apples so that variations in my training plan (different types of workouts) would not affect the result. I have power data for at least a portion of each of the past three seasons of Tuesday Worlds group rides - 2007, 2008, and 2009. So I made mean maximum power (MMP) and mean maximum normalized (MMNP) power charts using only those rides for each of those years. They are shown below. As you can see, 2008 was a crappier year than I thought. But more importantly, look at the huge jump in my MMNP in 2009 relative to the jump in MMP. I've sacrificed FTP by doing more L5 intervals and fewer TT training rides, but it's definately benefited my ability to repeat hard short-term efforts in RR (or crit) type events. That's the only conclusion I can draw so far - I'll keep pondering it.

Next year the goal is to move both lines to the northeast while maintaining a good aerobic engine for TTs also.

Monday, September 07, 2009

Negative Decoupling at 175 Watts

My 225-watt test showed 8% decoupling in a 30-min test. (later determined that it wasn't really 8%, more like 3-5% if I used the correct calculation method). I wanted to see the results of a lower wattage test, so I did an 80-min decoupling test at 175 watts.

Not only did I not find any evidence at all of decoupling, the result was NEGATIVE 2%. First 37 min: 176w at 123 bpm; Second 37 min: 177w at 122 bpm. Go figure.

I'll do the 225w test again to see if I can repeat the 8% decoupling result. If I can, then the next step will be to see at what wattage the decoupling effect starts to occur. Will it be at an abrupt wattage or will it gradually decouple?

If I find that it's an abrupt point, will additional aerobic system training raise the 'decoupling point?' Will additional aerobic training lower the 8% decoupling I see at 225 watts? Lots to investigate; but that's ok - I have until Spring.

Wednesday, September 02, 2009

More on Friel's Decoupling

Friel has a simple summary of his decoupling thesis at:

I'll summarize it even more: He says that for serious cyclists, aerobic fitness is best developed by riding at 65% to 75% of FTP. That puts me at about 200 watts, or upper portion of L2. He says if I'm training for longer road races, my decoupling should be less than 5% for 2 to 4 hours.

Calculate it by taking NP for the 1st half of the workout and dividing by average HR for 1st half of workout to get (NP/HRave) = A. Do the same for the 2nd half of the workout to get B.

Then check the percent increase by taking [(B-A)/A] x 100. If this percent decoupling is greater than 5%, aerobic fitness is not fully developed (unless heat or improper hydration have played a role).

I'm going to try a longer, slightly lower power test today (maybe 200w for an hour) to see how the decoupling looks.

Tuesday, September 01, 2009


Joe Friel has written lately about decoupling. That's when you're exercising aerobically (at sub-threshold) and your heartrate is not consistent with your power output. I used to use a coupling test when I was training for triathlon. I'd hold my heartrate constant while running on a track. The further I had run after 20 minutes, the more aerobically fit I was. I was amazed at the variation throught the trainign season back then (2001).

So I decided to do a coupling test on the bike yesterday. I put on the heartrate monitor, warmed up, and did 30 minutes at tempo (225 watts for me). I felt nice and steady for the whole interval and was on Hwy 11, which is flat. Wind was minimal.

The ride felt very consistent, so I was surprised to see later that my heartrate gradually rose during the interval, starting in the low 140s and finishing around 150. My threshold HR is about 160. I sort of had a plateau in the middle, but it didn't last.
Supposedly this means that my aerobic system is not well-developed at the moment. I look forward to doing more aerobic work during the fall and winter to see if I get a more coupled 30-min tempo result. If that does happen, maybe I can use this very easy test throughout the season to monitor my aerobic fitness and do more aerobic work when I see things start to "come apart."