Originally Posted by itsnevertoolate
I am 58 years old have a MHR of 188bpm and a RHR of 57bpm. What then is my 'lactate threshold heart rate' and how do I determine it?
That's a very complicated issue and there is no simple answer. The fact that you apparently actually know your HRmax and give a resting (first thing on awakening in the am?), means you might be anticipating using the Kivornen formula.
I've found this to be representative of the situation: (from
"While many athletic-minded people think that lactate threshold coincides with about 90 per cent of maximal heart rate, the truth is that it varies tremendously from person to person, and of course it also varies according to your fitness level. If you're a real stud, your LTHR (lactate-threshold heart rate) might actually be at 95 per cent of MHR; if you're a beginner, it could be at 65 to 70 per cent. If you're neither, LTHR could be nearly anywhere, depending on your previous training, overall fitness, and individual characteristics."
Many articles will state it's 80% for the moderately fit and 85% for a very fit. The Kivornan approach (described in the article linked above) attempts to adjust the LTHR for the fact that when you train at or above it, the LTHR increases and your resting HR decreases. So Kivornen formula gets a new value every time you get a different resting HR. if slavishly stay at the same HR, you'll decondition.
I try to spend time above 85% and even 90%.
Not a bad discussion on the subject in one of my favorite exercise/nutrition physiology books which can be read here for free yet:
It starts around page 489.
The pros like Armstrong actually get their blood drawn and compare lactic acid concentration with power generated. They apparently make kits to do that your self.
On the 220-age formula. If you are going to use that, forget it and just ride hard. There are at least four formulas and that one is probably the worst. It gives a value 22 to 24 below my measured max. (actual 172-174 at age 70 compared to a calculated of 150). I've been seeing 172/174 for around 6 years now. It doesn't necessarily decrease with age if you are fit.
Here are three of the four:
"Formula #1: The first formula involves simply subtracting your age from the number 220 (for men) or from 226 (for women). This method is preferred for beginning runners, those who have been leading a sedentary lifestyle. MarathonGuide.com Simple Heart Zones Calculator
Formula #2: The second formula is very similar, but is preferable for those who are already quite active. For this formula, simply subtract half of your age from the number 205.
Formula #3: The third formula runs along the same vein as the two preceding it. For men, subtract 80% of your age from the number 214. For women, subtract 70% of your age from the number 209. "
Number 2 gets the closest to mine, but it's coincidence.
Getting your HR above LTHR really has an impact. I've never measured my true resting HR. My HR at rest is typically around 57 or so after sitting a few minutes. The day before my annual physical I had spent close to 45minutes above 80% and a significant amount above 85. The good doctor had me scheduled for an electrocardiogram.
I'm laying on the couch while the technician hooks up the probes and she runs the electrocardiogram. She exclaims "your heart rate is 47!". I was as surprised as she was.