jjjtttggg said:I'm 40 years old, been cycling for about two and half years. After reading up on training techniques, I think I want to do some longer interval type training (say 3 x 15 to 20min intervals with 10-15min recovery) roughly at my "lactate threshold". The question is how to get an idea of what it is. I've heard I should ride for an hour as hard as I can and use the average heart rate. That would lead me to something like 160-165bpm, which is what I've used as my guide for the last year or so. However, this weekend I raced in a 45mi race, mostly gentle rolls, but with one decent hill of about 100m in 0.6mi. Finished 30th out of 40 🙁 Anyway, my average heart rate for the entire race, which took me 2 hours 23min, was 173! I only dropped into the 160s a few times after the first 15 minutes or so. Am I right in assuming that my LT is higher than I had previously thought. Also, If my goal is to increase my flat speed, am I right about the "3x15min at or just below LT"?
Appreciate any thoughts!
To clarify, LT has several definitions but the most common (correct definitions) are the workrate that elicits a 1mmol/L increase over exercise baseline levels (giving a lactate of ~ 2.x mmol/L) or a workrate that elicits a fixed 2.5 mmol/L. Workrate is power (measured in watts in cycling) or velocity (m/s or km/hr in running).
These intensities are somewhat low/moderate and can be sustained for up to 3+ hrs in trained cyclists. They're about 10 - 15% less power than that which can be sustained for a ~1-hr TT.
LT isn't defined by HR and by definition is an invasive procedure requiring blood to be drawn, usually by finger [censored] capillary measure or ear lobe.
However, to answer your query -- training at ~ TTpower is an excellent way to increase your base fitness and shift your LT and TTpower in an upwards direction. HR at these intensities can vary for many reasons, e.g., acute and chronic changes in fitness, altitude, euhydration, fatigue, cadence, environmental conditions, etc.
You should note that if training by HR (dependent variable) you should also use percieved exertion, as at a constant power (the independent variable) HR can vary (as per list above). During a period of heavy training HR can become depressed even though power may be unaffected. For e.g., at present i am in a heavy volume period of training and my HR has dropped significantly at all power outputs, however, with a couple of rest days my HR will return to a 'normal' level for a given power output.
Ric