Monday, December 14, 2009

Lower and Upper Training Thresholds

(chart ref. Dr. Andy Coggan)

If you'be been around cycling for a while you've undoubtedly heard the terms/words: Lactate Threshold, Aerobic Threshold, Anaerobic Threshold, Ventilatory Threshold, etc. All of these words are mostly used to describe significant reference points for setting up power/heart rate training zones.

Technically, Lactate Threshold (LT) is the point where lactate levels in the blood first increase over your baseline levels. When your lactate levels reach a point that is 1 mmol/L above your baseline, it is referred to as your Lower Training Threshold (LTT)- designated LT1 (see graph.)

Wonderful, but how the heck do I know when my blood lactate levels reach this point? (I'll answer that question in a little bit). After all, it's not like everyone (or even me with all my toys) has a blood lactate analyzer in their back pocket to measure their blood lactate levels during exercise. And, if there is a Lower Training Threshold (LTT) is there an Upper Training Threshold (UTT)? Yup, there is. That point is the highest level of intensity at which your body is able to process the by-products associated with carb metabolism at the same rate they are being produced. Simply put, as exercise intensity increases more lactate is released into the blood to a point where production is faster than your body can process it and starts to accumulate. Thus, an upper point or Onset of Blood Lactate Accumulation (OBLA) designated LT2- see graph.
The key words here are "increase" (where LT1 occurs) and "accumulation" (where LT2 occurs)- see graph. As a rough rule of thumb for most athletes: LT1 occurs at 2mM blood lactate and LT2 occurs at 4-6mM blood lactate. But, I repeat, that's a rule of thumb and everyone is different...let alone it also differs between sports. This the primary reason I do NOT own a blood lactate analyzer or have a reason to buy one to find FTPs for my athletes. I'd be able to find LT1 pretty easily but how do I know if/when the athlete is at LT2? Is it 4mM, 6mM, 8mM, etc? You can see from the first graph that there is a pretty substantial power range between 4-6mM. (No, this is not my chart..I can only dream of an FTP that high)
Ok, so how do you measure both your LTT and UTT without going out and buying a $500 portable blood lactate analyzer and sticking yourself every minute to find both these points on the graph? According to Thomas Chapple, author of "Base Building for Cyclists" (and a recommended read) the best way to determine your LTT is to do a Critical Power test for 30 minutes, aka CP30. (CP30 is nothing more than your average sustained power during a 30 min. Time Trial.) Your LTT will be 55-75% of your CP30 power. So, if your CP30 is 300 watts, your LTT range will range from 165-225w. How about your UTT? That will be 85-95% of your CP30 power, or 255-285w. BTW, your Functional Threshold Power (FTP) is a good indicator of your UTT. That is why I use Hunter Allen's 20 min. FTP test to determine Power Training Zones for my athletes vice the 30 min. TT that Mr. Chapple suggests.
During the base training phase (the phase you should be in right now in your ATP), you want to be spending the majority of your traning time/power in the LTT range. The UTT will usually drop and the LTT will rise during this early base phase. Say what? That's right..according to Thomas Chapple, your UTT will drop and your LTT will rise. What's happening is that you're actually bringing the fitness ceiling down so that you can build a larger foundation that will support a higher, stronger ceiling. It doesn't take as long to put the ceiling back up as it takes to build a larger foundation. I know..I're probably thinking (like I was when I first read this) that this is a time of year I want to increase my fitness level (or FTP)...NOT decrease it. But, you have to remember one VERY IMPORTANT takes YEARS to develop your aerobic energy system and only a couple MONTHS to develop your anaerobic energy system (or ceiling). Oh, and in case you haven't figured it out yet...the LTT is ridiculously low if you're one of those guys that like to ride hard 24/7- 365 days a year. (You can see from the 2nd graph that it's in the L1/L2/L3 power levels). In fact, I really doubt you'll be able to effectively train in this range at all because you're going to convince yourself that it's a waste of your time. If you think I'm nuts or completely lost it..go back and read my blog about Base Building and read the benefits of riding in the lower power ranges. These benefits are well documented, and proven, by the best PhD weenies in the business. And, who can argue with them? I can't. At least I'm not ignorant enough to argue with them.
Yes, you MUST go slower BEFORE you can go faster. What you want to do during this base building phase is to build a large foundation that will support a higher, stronger ceiling. Makes sense to me..hope it makes sense to you. Power ON! Coach Rob

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