Lactate Threshold Testing: The Basics

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Two renowned coaches I connected with, Siri Lindley and Joe Friel, each acknowledged the benefits of lab lactate threshold testing but agreed that the costs were an issue. One of Lindley's athletes actually worked with Thomas in the past and while the experience was helpful, price was a factor. Lindley, based in Boulder now, hasn't been able to find a lab near her to conduct similar testing at an affordable price. "We don't depend on testing like that so (I) didn't push to find someone to do it," she said. When Friel was more active coaching athletes, he'd have them test in the lab once a year during the base period of their season while adding regular field tests every 3 to 6 weeks. "Heart rate remains fairly constant over the course of the season but power and pace can (and should) change dramatically," Friel explained. "If the various factors (weather, food, course, etc.) are controlled then this is more like a 'standardized' race and gave us real-life data that could be applied to training and racing. It's also 'free' so we can repeat it as often as needed."

The benefit gained from my lab experience is arguably priceless though. For as long as I've known my coach, he's chided me on occasion for training harder than I need to. Something about "extra credit" not always applying to training intensity. (But it sure is good for Strava trophies!) This unfortunate truth manifested itself in my lab results. While my lab-tested VO2max was on the high side (close to 13 mmol), efficiency apparently is not my strong suit. I'm good at suffering, in other words. The steady-state threshold data, the power one can sustain for an hour, yielded borderline suboptimal performance levels. Sometimes it's easy to ignore what someone is telling you—even if it's that coach you're paying. Ignoring someone when they show you scientifically verifiable data is a lot harder.

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Thomas suggested a training regimen heavily focused on improving aerobic and lactate threshold zones, which would feel easy to me based on where I had been training. While my coach was planning to prescribe the same program, my time with Thomas convinced me to simply trust and follow said plan more than I might have on my own.

Four weeks after visiting Trio, I conducted a one hour FTP field test. While it may have been a fluke, my steady-state threshold was dramatically higher than the numbers Thomas had set. A near 30-watt difference. However, all my "improvement" did was reset my FTP to a few watts north of where it was prior to the Trio lab testing. Why? Thomas said it's only possible to judge metabolic progress in a like-for-like situation, so I'd have to revisit the lab to confirm real progress. He added that age groupers with less "metabolic talent" and conditioning should think of steady-state threshold as between 75 to 90 percent of FTP. "In a TT effort over 60 minutes, you will for sure be able to hold higher than SST," Thomas said. "So perhaps you are fitter, perhaps the same. They are different measures in reality." If money were no issue, I'd revisit the lab.

As it stands, Thomas' analysis would adequately explain the watts displayed in the field test as it pertains to the lab-prescribed SST—gaining a few watts along the way possibly thanks to my Ironman Arizona build phase. I'd recommend lab-based performance testing to anyone as a way to further validate field testing. In the future, I may employ lab testing in the weeks leading up to an A-race to finalize appropriate power and running zones. In the meantime, I'll simply do a better job following my coach's training plan—something he might think as almost...inconceivable.

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