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Slowtwitch Forums: Triathlon Forum:
What Percentage of Lactate Threshold Watts and HR Should One Race an Ironman?

ironboom

Jan 26, 08 15:01

Post #1 of 7 (548 views)

What Percentage of Lactate Threshold Watts and HR Should One Race an Ironman?	Can't Post

There has been quite a bit of discussion with respect to racing an Ironman at a percentage effort of Functional Threshold. To be honest, I am not sure what Function Threshold is or how it is calculated. However, I had my Lactate Threshold heart rate and watts at that threshold tested today and was looking for some guidance as whether anyone had any informative opions re what percentage of (1) watts at LT level and (2) Lactate Threshold heart rate one should race an Ironman. Thanks in advance.

http://iron-boom.blogspot.com

(This post was edited by ironboom on Jan 26, 08 15:02)

Monsieur Trois

Jan 26, 08 16:44

Post #2 of 7 (524 views)

Re: What Percentage of Lactate Threshold Watts and HR Should One Race an Ironman? [ironboom] [In reply to]	Can't Post

Paging Dr. Coggan!
From Allen and Coggan's book Training and Racing with a Power Meter.
pg. 44 "FTP is the highest power that a rider can maintain in a quasi-steady state without fatiguing for approximately one hour."
pg. 55, table 3.2 shows the LT training level as 91-105% of FTP.
pg. 177 table 10.1 "General Guidelines for Triathlon Events" shows an average power as a percentage of FTP for an Ironman to be approximately 68-78%. Of course they explain that it all depends on the athlete and level of training etc. They devote five pages on how to pace however so it isn't as simple as a mere table.
They calculate FTP this way:
20 minute warmup (65% of max. heart rate)...3 fast pedaling efforts at 100 rpm for 1 min. each, with 1 minute of easy recovery pedaling between each. After these ride easy for 5 minutes at 65% of max. HR...5 minutes all out "Punch it and hold it!"...10 minutes easy at endurance pace...20-minute time trial (don't start out too hard)...10-15 endurance pace...10-15 cool down.
Figure out averge power for the 20 minute time trial and then subtract five percent. The resulting number is your FTP. There is much more to it...I recommend the book.

Kevin P.

Jan 26, 08 18:21

Post #3 of 7 (492 views)

Re: What Percentage of Lactate Threshold Watts and HR Should One Race an Ironman? [ironboom] [In reply to]	Can't Post

From the "Power" thread:

I wrote an article that lays out my views of racing long with power, PE and HR. You may read some relatively small but important variance in the advice given for upper percentages of FTP used in IM over changing terrain (flats, rollers, extended climbs) and in the final predicted values. However, an athlete's FTP physically changes // and so does ones ability to accurately name it. In the end, use advice to guide you as you find what works for you on your longest training days (repeatedly). That is where your real nuggets are found that will support IM execution.

http://www.gordoworld.com/.../12/racing-long.html

KP

Dr. Kevin Purcell DC
http://www.coachkp.com/
www.ultrafit.com
Certified Active Release Technique (ART)
USAT Certified Coach

ironboom

Jan 28, 08 5:31

Post #4 of 7 (383 views)

Re: What Percentage of Lactate Threshold Watts and HR Should One Race an Ironman? [Kevin P.] [In reply to]	Can't Post

Thanks. I looked at your article. How does FTP compare to lactate threshold?

http://iron-boom.blogspot.com

(This post was edited by ironboom on Jan 28, 08 5:41)

Dig It Tri

Jan 28, 08 6:59

Post #5 of 7 (339 views)

Re: What Percentage of Lactate Threshold Watts and HR Should One Race an Ironman? [ironboom] [In reply to]	Can't Post

Annoying to say but it really depends on how one defines LT. There are 3 to 4 definitions in use right now of "LT" and the specifics matter a whole lot when comparing to FTP. The textbook answer of when lactate starts to accumulate is not specific enough as we all agree on that, it is how one measures the accumulation that matters.
Jason
Dig It Triathlon and Multisport
www.digittri.com

drfunk000

Jan 28, 08 8:03

Post #6 of 7 (306 views)

Re: What Percentage of Lactate Threshold Watts and HR Should One Race an Ironman? [ironboom] [In reply to]	Can't Post

This is a _question_ rather than an answer.

But... have you tried a race simulation ride with a run afterward? Wouldn't this give you a good idea of what % you can maintain over the distance?

Ashburn

Jan 28, 08 9:54

Post #7 of 7 (256 views)

Re: What Percentage of Lactate Threshold Watts and HR Should One Race an Ironman? [ironboom] [In reply to]	Can't Post

In Reply To:

Thanks. I looked at your article. How does FTP compare to lactate threshold?

LT will be in the 85-90% range of FTP for most fit athletes (fit folks can hold LT effort for 2:15 to 3:00, give or take). It's going to be different for everyone, and I don't recommend trying to nail it down. What matters is your functional ability to ride certain durations and intensities. Use percentages of functional abilities to estimate pacing strategies, not biological markers that you can't even measure without taking a blood sample.

Don't spend time chasing LT-based fitness markers.

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