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Lactate Threshold

malaholic2010-05-02 14:57:56 +0000 #1
I did my 2nd Spinervals workout today with the new trainer, this time the focus was "building the aerobic base". They say to keep your heartrate about 10 b.p.m. below your lactate threshold. Well, I have no idea what my lactate threshold is, and it seems to be a rather complicated measurement. Does anyone here know of an easy-ish way to approximate where one's lactate threshold is? Thanks!

(Incidentally I kept my HR average at about 145-150 for this workout....I hope that was at least ballpark....)
Wahine2010-05-02 15:11:01 +0000 #2
The easiest way to estimate your LT is to do a progressive set. It helps to have a buddy to record things as you go.

Warm-up for 10 minutes, be sure to spin up to a high intensity about 3 times during your warm-up but for only 30 sec.

Then start riding at a gear ratio and cadence (80 to 90 is good) that is comfortable but not easy, something that you know you could maintain over 30 min or more. Every minute move into a harder gear. This is easiest if you start out on your big ring in the front and your sec from biggest ring on the back, then you can just keep dropping into a smaller cog on the back. The key is to maintain your cadence throughout the set. Have your buddy record your heart rate and your rating of perceived exertion at the end of every minute. At some point you will suddenly start breathing a lot faster. This will be a sudden change, not gradual. Have your buddy record your HR at that point. Keep going until you run out of gears or your legs fail. The HR at which your breathing suddenly shifts is a good estimate of LT.

After all is said and done, graph your HR against time and somewhere around the estimated LT you should see a sudden increase in the slope of the graph. This confirms that what you're looking at is the HR at which your primary energy system usage changes and you're starting to go into oxygen debt.

The other way to do it is to estimate your LT based on your max HR. Hopefully you know what your maximum HR is on the bike (actually observed it). Approximately 60 to 65% is an estimate of LT. This formula is completely useless for athletes with a lot of training in their background.
kelownagirl2010-05-02 15:28:08 +0000 #3
Minor but related thread-jack - Wahine - my friend's husband is a tri coach and he does lactate threshold testing using a computrainer (and blood tests). I was thinking of getting him to test mine so I can train more efficiently. Do you think it's of any value? And if so, what time of year would be best?
Wahine2010-05-02 15:09:06 +0000 #4
Yes. Definitely worth while. Even better if he does VO2 Max testing. But LT testing is great. And the best time to do it is now, at the beginning of a training season after you have a couple of weeks of consistent riding in your legs.



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