Sunday, December 10, 2006

Double-deflection Lactate Threshold

After combining information I've obtained from reading, from lab tests and discussions with Tony Myers at ATS in Atlanta, and with Richard Wharton, Online Bike Coach, in Dallas, I've determined that I have a somewhat unusual characteristic. At a low effort level (for me it's at about 150 watts, or 135 bpm, which is in my endurance training zone), the lactate concentration in my exhaled breath (and bloodstream) starts to noticeably increase. For most cyclists, that's an indicator that with a little more effort, a pretty good muscle 'burn' and a limited amount of exertion time is in store. But since I know that my functional threshold is at 238 watts and 160 bpm, that doesn't apply for me. I have a double-deflection lactate threshold. Tony says he has seen one other client exhibit the same traits, and Richard said that he has seen it once, in Charles Kulp, to whom his new book is dedicated.

The 'diagnosis' is both good news and bad news. The good news is that one of my negative genetic traits, a low initial lactate threshold, is offset by a positive genetic trait, a high capacity to buffer lactic acid. It probably means I can ride for a long time at very near my threshold (about 4.25 hrs yesterday at 89% intensity factor). But I think it also means that once I do exceed my threshold, I can't stay there very long, but can recover quickly for another short burst. Essentially, I may have lots of matches in my book, but they aren't very hot.

In the next few months, I plan to: 1. Perform testing to see how my blood lactate levels relate to what I've seen from the ventalatory threshold testing I've done so far, and 2. Figure out if I should modify my training in any way to better accommodate my type of body chemistry.