This is my world of cycling and just a fun way for me to share my experiences, thoughts and joy I have for cycling. Thanks for visiting Cycle Jabber and good luck in your training! Dirk Friel

Wednesday, February 07, 2007

Revisiting Mt Evans Power #'s by Request...

I had a request to revisit my Mt Evans race numbers for last year. This is a great topic for this time of year. Whether Mt Evans is your goal or not, this is the time of year to analyze your upcoming races so you have plenty of time to create workouts which will match the expected race stress.

I was asked how much I weighed at Mt Evans last year. I was 75.9kg.
My race time was 2:05 and it was considered a slow year in the pro/1-2 field as we crawled along the first 10 minutes. I only averaged 216 watts for the lower 3 miles.
My avg watts for the race was 248w and 150hr.
My FTP at 5,500ft at that time was ~360w and 178hr.

After the first 10 minutes the pace picked up and I averaged 287w/158HR for 26' until I was dropped and decided to ride at my own pace.

From 7,500ft to 10,000ft I averaged 258watts/165hr
From 10,000-14,000ft I only averaged 222w/160hr

Obviously my power rapidly fell away, while my HR relatively stayed the same. This is a concept introduced to me by my father Joe Friel and he terms this "fall away" as Decoupling, or Pw:HR decoupling.

My Pw:HR decoupling value was for the entire race was 15.7%

Here's how to calulate your Pw:HR decoupling...
1. Divide average power/pace by average heart rate for the first half (pace is probably best measured for this purpose in mph)
2. Divide average power/pace by average heart rate for the second half.
3. Subtract 2nd half product from 1st half product.
4. Divide by 1st half product.

Interesting to note is the decoupling value for each section of the race:
-First easy 10' was -6.2% meaning I gained strength, or became more economical, due to the warm-up effect of an easy pace.
-Fast paced attacking section was 4.39%, I am starting to fade.
-7,500ft - 10,000ft was 2.64% This is lower compared to the previous section because I settled into my own rythm and rode solo.
-10,000-14,000ft was fell away at a wopping 6.34% simply due to the extreme altitude.

The difference between the avg watts of my 10k+ft section (222w for 42') and my first 42' (268w up to 7,700ft) was ~20%.
The mathematic models of pacing are hard to apply to such an extreme race as Mt Evans due to the rapid change in altitude. Power at Lactate Threshold and VO2max both drop as the altitude goes above 5,000ft, as compared to sea level.
This is exactly why you want to live high, train low. It is hard to maximize all systems at high altitudes. The "aerobic ceiling" simply collapses in on you reducing the amount of work your muscles can produce.

posted by Dirk at 8:33 AM


Blogger doperssuck said...

Awesome data!

8:30 AM

Blogger Keith said...

thanks so much! this is a great post, and even more than i was hoping for. evans is not really a goal of mine - i weigh 76kg as well and as a result am not a great climber. however, one of my strengths is a high endurance wattage relative to my threshold, and current tests are predicting that my endurance level (~1.25 mmol/L) at 5500ft should be around 250w in july. and evans is really an endurance workout rather than a threshold one.

i did evans a few years ago and did everything wrong, came away with what i considered to be a terrible time. since then i have started racing a lot and have made big improvements to all my power levels. so i was thinking that it might be nice to try for a better time this year. except that all the power calculators have been telling me i would need to average 300w to finish in a mediocre 2:15!

that sounded pretty extreme to me, so i was hoping they were wrong ... and it looks like they were. i suspect a big part of the reason is the lower 6 miles.

11:48 AM


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