# Lactic acid threshold



## ywang (Jun 6, 2014)

Hey guys! I just got into collegiate racing this past academic year and I've been hearing people talk about lactic acid threshold. How exactly do you measure it, and how does it relate to anaerobic capacity? It seems it's all too critical for sprint training (which interests me). Thanks a bunch!


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## mkadam68 (Feb 19, 2008)

The most valid way of measuring is with blood tests for lactate buildup during a cycling workout on an ergometer. A simpler, cheaper way is to ride lots, pushing yourself here & there, and learning where your limit is (the limit is that which you could ride "all day", in quotes). That'll give you a good estimate range to start with.

Then, do a 20-minute VO2max test to test this limit, see if it holds true. Ride at this limit for 20-mins, see if you can last the whole time. Afterwards, adjust your limit if up or down. Next couple weeks, ride some more to "test" your new number, and re-test a couple weeks later. Repeat.

How does this relate to sprinting? The harder you work, the more tired/fatigued you are and the slower your sprint will be, or not as long (150m instead of 200m), etc... This concept of "working harder" relates to your threshold in this: the more time you spend near, at, or above threshold, the harder you are working and more fatigued you will be.

In pro racing, you'll see riders trying to sit at the back and in the draft, riding at a lower effort and conserving their energy. Just that simple (not really, but you get the basics).

This is the concept of lactate threshold. Anaerobic threshold is generally higher than that, and not overly relevant to your concerns about sprinting, especially in races. If you're sprinting at the finish, you don't care if you hit max, let alone exceed anaerobic threshold (in a sprint you should be anyway) cause the race is over. If it's earlier in the race, and you're trying not to get dropped up a long climb, you should ride at your lactate threshold and try to slowly come back without blowing up. If it's just a surge on flattish terrain or just near the very summit of a climb, sure, go anaerobic to see if you can hold on. Then pray the pace lets up or you're going downhill so you can recover or you're shot.


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## Coach Matt (Jun 17, 2014)

Hey There...

Cool on the collegiate racing! Lactate Threshold is a common reference point for training intensity. The short answer is that it's roughly the Power/HR/RPE you can hold for circa 40km. The other reply is correct that a blood draw is a good way to get it done...and as luck would have it, lots of universities do the testing if they have a phys program of some sort. You can also volunteer to be a test subject sometimes. LT/AT (Anaerobic Threshold) are somewhat interchangeable. Here is where I have a different opinion than the previous reply guy. I use time stamps (60s, 90s, 1min, etc) to help explain the different physiological systems in use in cycling. If you use power to train we can get a measureable number for each system and you can train to improve, but heart rate (HR) is also a very valid metric especially for new riders. Your average HR during that same crica hour effort is gonna be pretty close to your lactate threshold HR. Similarly you can use Perceived Exertion to "see" how hard you are working in each time stamp/phys system.

For 'Threhsold Efforts" you want the interval to last 10 - 60minutes at your target HR/Power/RPE = 6-7.5 on a 10 scale. Sprint anaerobic efforts are much shorter, in the 30s - 2min range, while VO2's can range in the 3 - 8 minute per interval range. ALL are essential for racing. If your threshold is too low you wont' have any energy left to sprint. If your sprint power isn't developed you won't have much to give anyway...Racing often comes down to those last 5-10 minutes of really high intensity leading to a sprint or solo victory....the trick is getting to the last part of the race with matches to spare!

Matt


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## crit_boy (Aug 6, 2013)

Coach Matt said:


> and as luck would have it, lots of universities do the testing if they have a phys program of some sort. You can also volunteer to be a test subject sometimes. LT/AT (Anaerobic Threshold) are somewhat interchangeable.


I participated in one of these. Body fat in dunk tank, lung capacity, VO2 max breathing face mask thing, multiple 40K TTs with multiple blood draws, six muscle biopsies (bad part). 

You learn a lot of info about yourself. 

However, I was cautioned before doing it that you cannot get all wrapped up in the numbers. In a story related to me, a local racer found out his VO2 max was statistically lower than other cat 1-3 racers (lab tech said local racer guy reacted like he just found out he had the scientifically confirmed smallest penis ever).


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## ESTrainSmartBlog (Feb 25, 2013)

In order to improve your lactic threshold, you have two options to improve it. You can either train to improve your lactic clearance or improve your lactic tolerance (accumulation). There are specific intervals for this. One variable that's finally starting to gain attention is cycling economy. It can compensate for a low VO2MAX and lactic threshold.


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