# Fifty Plus (50+) - What is my lactate threshold heart rate?

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itsnevertoolate
08-29-09, 12:09 AM
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?

Hermes
08-29-09, 01:06 AM
Lactate threshold heart rate or power is that HR or power which you can maintain for a long period of time such as an hour at constant power - note I said power or level of effort and not heart rate. BTW, you can maintain a heart rate at which your power decreases over time. That is NOT your LT. Generally, it is determined in a performance lab by taking blood samples and testing for lactate as you ride your bicycle at ever increasing power or level of effort. When you build up lactate in your blood, you power begins to drop. LT has little to do with max heart rate or resting heart rate.

There are other ways to get at LT. Some people do two back to back 20 minute time trials at the maximum effort you can maintain without slowing down and take the average heart rate of the two.

If you do an actual time trial race, your LT is 95% of your average HR of the race.

tsl
08-29-09, 05:54 AM
What timing!

Heart Rate Training Zones

What's the matter? You want to calculate your heart rate for different training zones but it's confusing. Some authorities say to base the percentages on max heart rate while others suggest calculating from lactate threshold. One book says to figure max heart rate using the 220-minus-age formula while another says you should get a lab test. Can't this be simpler?

Here's help: If there were a "perfect" range for training and recovery rides, it seems like the experts would agree. In fact, no such ideal heart rate exists. That's because heart rate (HR) for a given power output varies from day to day depending on your state of hydration, mental condition, whether you're tired or fresh, and environmental conditions such as heat and humidity.

In addition, the 220-minus-age formula for determining max heart rate is based on an ancient guesstimate that has a standard deviation of 11. Thus, for many people the max HR predicted by this formula is not very close to reality.

Our advice is to base exercise zones on your lactate threshold (LT) rather than on your max heart rate.

LT corresponds to the highest average heart rate you can maintain for 45-60 minutes. You can find it without pushing yourself to your painful max HR, an effort that requires medical supervision.

A good way to find your LT is to ride a fairly flat 15-mile course at a hard pace. Use a heart monitor that averages heart rate for the distance or just check it occasionally to see where HR settles.

You'll quickly find that you can maintain a certain high HR, but if you go a few beats higher you'll start panting and be unable to control your breathing. Trial and error will reveal the highest HR you can maintain for the distance. That's your LT.

Three simple exercise zones based on your LT heart rate are sufficient. These guidelines should work for most riders:

Recovery takes place about 40 beats below LT
Endurance is built on rides about 25 beats below LT
"Breakthrough" training is done from 10 beats below LT to about 5 beats above

No heart monitor? You can do just as well by monitoring your perceived exertion. For instance, recovery rides should be so easy that you barely feel the pedals. The idea is to take a "walk" on the bike.

Hard efforts, such as intervals and climbing, should be at the limit separating steady-but-labored breathing from panting and gasping. By experimenting you'll find this LT boundary.

08-29-09, 08:09 AM
great timing indeed, tsl!

chuckb
08-29-09, 01:26 PM
I finally had this done with blood testing on a trainer and the results were very close to my field test. The field test that I think works is very simple. Find a long climb that takes 30-40 minutes (I use Skyline Drive in Virginia.) Ride up that climb at the fastest speed that you can sustain for the whole climb. Your average HR on the climb is your LTHR threshold.

For me, the field test gives about 160 for LTHR, the blood test indicated 158. I like the sustained effort on the climb better because I find it easier to keep a fixed effort on a climb instead of a flat. Other than that, it is just like described above from roadbikerider.com.

itsnevertoolate
08-29-09, 02:08 PM
Thanks for the input.... I'll try both (flat and hill effort).

Allegheny Jet
08-29-09, 02:23 PM
Bear in mind that the LTHR will move as your fitness improves or regresses. I'm currently riding about 5 BPMs higher than in the late spring.

jppe
08-29-09, 02:33 PM
Another simple way to determine it is to ride hard enough for 25 mins such that you throw up-very old school but you'd be surprised how accurate it is!

alcanoe
08-29-09, 07:55 PM
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
http://www.pponline.co.uk/encyc/0141.htm )

"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.

http://www.iherve.com/fitness/HRs_calculations.html

http://www.chestjournal.org/content/94/1/95.full.pdf+html

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.

Al

08-30-09, 07:57 AM
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
http://www.pponline.co.uk/encyc/0141.htm )

"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.

http://www.iherve.com/fitness/HRs_calculations.html