Lactate Testing - Marathon Pace

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yacky

15 posts since
Sep 20, 2007

Nov 19, 2007 6:37 PM

Lactate Testing - Marathon Pace - Heart Rate

I posted earlier asking question about this stuff, so I figured I would give my personal "experience" results for anyone who might try this.

I poked myself multiple times to find out at what pace/heart rate I could run for 30 minutes and have a lactate reading of 2.5 mmol a week before the Philadelphia Marathon. From reading, it was my understanding that this is the mmol level/pace marathons are run at.

The heart rate I came up with was 152 at a pace of 7:45 in moderately hilly terrain in 40 degree weather. So, I determined that since Philadelphia was flat I would run in the 3:20 pace group which ran at a 3:18 pace. (Please note that I have never run a marathon before.) I also figured that if I was running well at mile 13 I would go for a BM qualifying time otherwise I would try to turn this into a long training run.

Well, I found my heart rate was too high/158 (Philadelphia is not flat between miles 6-11) at that pace so I eventually dropped back into the 3:28 pace group. (This group was a little too slow.) My heart rate declined to 149 by mile 10 and by mile 18 it was back to good old 152 which was supposed to be 155-156 compenstating for heart rate drift. I felt great, no cramping/struggling to keep up. So, I slowed up and did a recovery run (10:00/mile pace) to mile 20. (I want to "save myself" for more training until I can post a 3:15:59 time)

MY BAD IDEA:
So, I found myself self imposing a 6 mile walk back to the finish line. I have never run a marathon, and I having done 7 long runs averaging 24 miles each, I figured I would finish. Well around mile 21 I started to get cold (40 degrees outside) and around mile 22 I started to cramp. So, I in an effort not to freeze to death and avoid cramping I found myself having to lightly jog when I would feel myself cramping to the finish line (The irony....)

So, today I am sore, not terribly and plan on resuming training to get to my goal. As far as the testing goes, I am a true believer and will be testing myself monthly until I am ready to put up qualifying run.

mcsolar99

1,018 posts since
Aug 14, 2007

1. Dec 26, 2007 7:52 AM

in response to: yacky

edited to add: i'm fascinated by this stuff, but haven't done any lactate testing myself.

couple of questions:

(1) what is the error bar for your 2.5mmol heart rate calculation? there must be some interpolation or fitting involved, and there are errors in that... is it +/- 2 bpm or +/- 8 bpm?

(2) does your plan have an average hr equal to this lactate value, or are you trying to stay within some range

(3) what kind of half marathon time can you run, and what lactate level does that predict?

http://This message has been edited by mcsolar99 (edited Nov-19-2007).

hurryinhoosier

61 posts since
Nov 14, 2007

2. Nov 19, 2007 8:21 PM

in response to: yacky

I am curious - are you paying to have your Lactate measure each month? Just curious how you are measuring this so frequently.

yacky

15 posts since
Sep 20, 2007

3. Nov 19, 2007 10:13 PM

in response to: yacky

I bought a device called Lactate Pro online. The device was about $400 plus $100 in test strips and a pricker. The measurement error I would say is within +/- 1 bpm. Now that I have the device it costs about $1 per *****. The good news is that all I need to do is run at 152 bpm and one at 154 bpm check my pace relative to what temperature/humidity it was run at, and I know exactly where I am compared to my baseline testing. So as long as I am not sick/tired on testing days, I can measure my effort level without going full out and running a marathon to find out that I am going to be way off.

Let me give you my data...

Max HR - I believe it is 182 (not sure... I have never done what is really necessary to figure that out...)
Age - 37
Resting HR - 38 bpm
Weight - 170 - 5' 10.5"

At first I tested myself on a treadmill in a 75 degree room and pricked myself every 10 minutes at increasing speeds, I started at 7.5 mph. I had a baseline 2.0 to 2.1 mmol. Then at somewhere between a 7:30 pace and a 7:08 pace I went from 2.2 to 2.9 mmol at an HR between 152 and 162 for the last 6 minutes of these runs.

Armed with this information, I took it outside. I would "warm up" to a heart rate to be tested over 10 minutes take a blood sample and then run 20 minutes at the same heart rate. At first, I tried 158, but my mmol was 6.0, then 156, then 154, finally at 152 it was at 2.6 mmol, but at 154 it was over 5.0 mmol.

At a 156 HR for 40 minutes my mmol is 5.7, so clearly I would not last at this pace after the sugar ran out (1.5 hours). I tried 154 for 40 minutes and was at 5.6 mmol. At 152 and below.... I am steady... no build... I am steady at the higher HR but at too high of lactate levels. Eventually, my lacate goes flying... I did a 12 minute sprint and my lactate went to 16.3... (I feel like a lab rat)

Obviously when doing these tests my heart rate varied +/- 2 bpm but I was very diligent and it was not for long at the extremes. Hills matter - Do not let your HR go up on hills or lactate builds... While running the marathon with a pace group, I took this into consideration on hills. The pacer was running up the hill too fast and breaking down the hill. I found I was much better off watching my HRM up and down the hill. I would complete the hill ahead of the pace group (gain time on the downward side) with a lower average HR then holding steady with them. I think the pacer is far below their threshold so it doesn't matter to them.

I think half marathon is much different from a marathon because in a marathon you can "hit a wall", so you cannot have lacate in your system for the first half at all, because when this happens, you burn all too much glucose and when it runs out, you are done. Since I was going to run a full marathon, I have not yet completed testing my upward boundaries. Here you try and test at what level you can run before your lactate spirals out of control. This is your 1 hour heart rate. I have tested up to 162 and still have not found my limit. If you found this level after a tempo runs, you would know your 1 hour limit HR. Then you would have to run slower than that. I would assume a running calculator would estimate that race fairly closely. Then what I would do is adjust the 1 hour pace/heart rate to match calculator time.

So the variables I would tweak for me are...
every 10 seconds per mile is 4 bpm
the treadmill is 15 sec per mile faster than pavement or 6 bpm
temperature around 70 degrees is 1 bpm
humidity is a killer above 60 degrees - I don't have enough data points at different temperatures yet - it is a big adjustment however
wearing a shirt slows me down until about 45 degrees (no wind)

What I find interesting is the heart rate is what matters. If I am running the same speed/temp/humdity/course but my heart rate is higher today, my lactate levels will go up if I am over 152 bpm.

And yes.... just a little OCD...

mcsolar99

1,018 posts since
Aug 14, 2007

4. Nov 20, 2007 9:03 PM

in response to: yacky

yacky, this is fascinating stuff. i also saw those lactate testers, but couldn't convince my running buddies to go in together to buy one. i'm envious

i'm surprised that your lactate varies so much over just a few bpm. in the only plots i've seen (in janssen, "training, lactate, pulse-rate", graphs 16 and 36) it looks like your variation from over 6bpm (158-152) covers a lactate change equal to a 15bpm change in his test subject. but i guess we each have a different lactate vs. pulse-rate curve?

i've tried running conconi's test a few times, but never had any luck with determining lt. have you tried that before?

my best marathon time was run at 154bpm. i've found a linear relation between my average race pulse-rate and the log of the race distance... seems to hold from 5k through marathon.

yacky

15 posts since
Sep 20, 2007

5. Nov 21, 2007 2:35 PM

in response to: yacky

The reason I think for the discrepancy is that the lactate curves are tests taken in 10 minute increments at different speeds. When I first did it on a treadmill I got the following...

The heart rate is an average of the last 4 minutes...

HR - Pace - mmol - Temp
135 - 8:00 - 2.1 - 70.8
140 - 7:47 - 1.8 - 71.4
148 - 7:42 - 2.1 - 72.0
152 - 7:30 - 2.2 - 72.6
158 - 7:19 - 2.6 - 73.3
162 - 7:08 - 2.9 - 73.9

Each run was 10 minutes followed by a quick poke and blood sample (90 seconds)

I think the curves in the book are done this way so there is not enough time to build the lactate levels up just like the test above. At first I was hopeful that I could run at a heart rate of 158. If I could have, I would have qualified....

So, I ran for 40 minutes outside with a HR of 156 and got a 5.7 mmol reading. I think my lactate tops out around 6.5 mmol before going crazy. The average is 4.0.

Anyway, I like the device and intend on running at my Boston qualifying time (adjusting for temperature) for 30 minutes and taking a measurement every month until I am ready to go...

However, after seeing the pain first hand needed to make that time, I have been considering trying to get myself 10 sec/mile ahead in an attempt to avoid that pain.

tigger077

691 posts since
Nov 19, 1999

6. Nov 22, 2007 10:16 PM

in response to: yacky

Your marathon pace heart rate will vary depending on how fast you can run one. Slower runners will have lower percent of their max heart rate because they have to be out there longer. I don't think there is any absolute lactate level for running marathons, as two people of equal ability can have very different numbers at the same pace. You should be able to get just as good a prediction by running a couple of races fro 10k to half marathon and then using Daniels VDOT tables to estimate your MP.

yacky

15 posts since
Sep 20, 2007

7. Nov 23, 2007 8:51 AM

in response to: yacky

According to the studies, your marathon pace is 2.5 mmol which is just above baseline of about 2.0. The reason is that if you are runnning at a higher lactate level than this your body is burning your sugar reserves and you will run out of them before you cross the finish line. (High lactate means your body is burning sugar) So, this test is very predictive of your ability. Slower runners will hit this 2.5 at lower percentages of max heart rate.

I really like the test because it only requires a 30 minute run at marathon pace to check whether you are ready so it is not disruptive to training.

10k races are not very predictive on the calculators for "slower" people and for a new runner how do you find your half marathon pace without running a few of them? Also, it is much easier to run a few 30 minute runs at different paces to find 2.5 mmol than it is to run 10k/half marathon races until you find your "optimal" pace. Even better, you can run the 30 minute test the week before the marathon without negative effects. The downside is the cost of the measuring device.

Here are some links:

http://beginnertriathlete.com/cms/Article-detail.asp?Articleid=1176&vote=8[/URL" target="_blank">

Peter Janssen
http://books.google.com/books?id=Ns4u0-N0q4MC&pg=PA141&lpg=PA141&dq=marathon+2.5+mmol&source=web&ots=_Qfdr9Ncpc&sig=B_4HprBXGhKwd3rcMKIMxcpC0VQ[/URL" target="_blank">

Brian McN

240 posts since
Dec 14, 2007

8. Nov 23, 2007 9:23 AM

in response to: yacky

With the Marathon there are other things to consider.
I could run easily for 30 minutes and be well within my lactate threshold at MP in training and still bonk late in the actual race if I'm not ready to take a pounding. I can't recall falling into oxygen debt in any of the Marathons that I've run which would cause a spike in my Blood Lactate levels yet I've not finished them all strong because of other limiting factors.

It is interesting though and useful info but there is more to consider.

tigger077

691 posts since
Nov 19, 1999

9. Nov 23, 2007 1:38 PM

in response to: yacky

quote:<HR>Originally posted by yacky:
According to the studies, your marathon pace is 2.5 mmol which is just above baseline of about 2.0. The reason is that if you are runnning at a higher lactate level than this your body is burning your sugar reserves and you will run out of them before you cross the finish line. (High lactate means your body is burning sugar) So, this test is very predictive of your ability. Slower runners will hit this 2.5 at lower percentages of max heart rate.

I really like the test because it only requires a 30 minute run at marathon pace to check whether you are ready so it is not disruptive to training.

10k races are not very predictive on the calculators for "slower" people and for a new runner how do you find your half marathon pace without running a few of them? Also, it is much easier to run a few 30 minute runs at different paces to find 2.5 mmol than it is to run 10k/half marathon races until you find your "optimal" pace. Even better, you can run the 30 minute test the week before the marathon without negative effects. The downside is the cost of the measuring device.

Here are some links:

http://beginnertriathlete.com/cms/Article-detail.asp?Articleid=1176&vote=8[/URL" target="_blank">

Peter Janssen
http://books.google.com/books?id=Ns4u0-N0q4MC&pg=PA141&lpg=PA141&dq=marathon+2.5+mmol&source=web&ots= _Qfdr9Ncpc&sig=B_4HprBXGhKwd3rcMKIMxcpC0VQ[/URL" target="_blank">

<HR>

The artical by Janssen is interesing, but I think there is more variability than suggested by the statement (bottom of P 141) that everyone should run MP at 2.5 mmoles per litre of lactate. Janssen himself says in the article (middle of P 109) that levels of lactate vary widely in athletes, so simply accepting a single number may over or underestimate your ability.

Noakes has said that the best single predictor of marathon time is your pace at anaerobic threshold. This is not the same as what the author calls aerobic threshold. Daniels' tables are pretty accurate predictors of performance, particulary if one uses race distances close to the one being planned. There are a couple of extra wrinkles in marathons, especially for slower runners because of heat and hydration issues.

Running at faster paces will certainly metabolize more sugar, or glucose, but this is a simplistic view of a complex issue. Muscles use primarily muscle glycogen stores, which are normally adequate for races below threshold paces. The issue is with liver glycogen, which feeds the brain and to some degree feeds muscles via blood flow. Liver glycogen supplies are normally only sufficient for three hours or so, and depletion results in the common syndrom known as a bonk, or hitting the wall. The solution is to take on energy supplies as you run via gu or clif shots or some other method. Fat stores make up the remaining source of energy, and interestingly this source supplies a greater and greater percentage of the total as exercise duration increases.

Having said that, some people are naturally high glucose burners, while others are naturally high fat burners. There is a normal distribution with a fairly large sigma for a large population. So what works for one runner may not work for others.

So the best way to determine your marathon pace is to find your anaerobic threshold, which is the point where you can race for an hour. It will fall somewhere between your 10k race pace (slower runners) and your half marathon race pace (elite runners) and can be used to determine how fast you should run in a marathon. I normally do my threshold work on a track. After a few attempts you can get pretty close without doing all the work on lactate testing.

yacky

15 posts since
Sep 20, 2007

10. Nov 23, 2007 1:40 PM

in response to: yacky

It is my understanding that bonking is caused by having used up your glucose reserves. Lactate is formed when glucose is burned in the muscle and there is not sufficient oxygen. At a level about 2.5 mmol (some have said as high as 2.9 (which is not much of a difference per mile at least for me) - most likely quicker runners since they finish sooner) you are burning very much sugar. The slight oxygen debt you run into at say 4 bpm higher is most likely unnoticable until it is too late. My guess is that if you did the test and held to the heart rate needed to stay at 2.5 mmol, you would not bonk, you would just end up running much slower. However, I am pretty sure that would be a good idea since your joints, tendons, and muscles would not be used to that kind of pounding.

What I like is the fact than my heart rate makes adjustments for a lot of other factors:
Am I climbing a hill too fast?
Am I descending a hill too slowly?
How much slower/faster should I run due to the temperature?
How is the humidity/wind effecting me?
Am I just not having a good day?

Easy to measure, completely objective, and once the initial tests are done; non disruptive to training.

It would be interesting to see what people's blood lactate levels are during a marathon at say miles 13.1, 20, and the end. Also, what they are when they bonk.... That of course would be very intrusive unless a non-racer poked you at a water station and kept the results...

bigapplepie

2,636 posts since
Dec 14, 2007

11. Nov 23, 2007 3:12 PM

in response to: yacky

What is your max heart-rate?

tigger077

691 posts since
Nov 19, 1999

12. Nov 23, 2007 5:13 PM

in response to: yacky

I didn't mean to give the impression that bonking was caused by anything other than low glucose reserves. I merely wanted to clarify that the particular reserve (the liver) is normally the cause because those reserves get used up before muscle glycogen. Lactate is merely a byproduct of glucose metabolism and is not the cause of muscle fatigue. (Nor is there a shortage of oxygen in the muscles.) It is excess hydrogen ions produced during high carbohydrate turnover (lowering blood pH) that likely result in the feelings of fatigue at pace above AT. (By running at your current AT you can actually train your body to run more easily at the lower blood pH, thus raising your AT, or in effect....lowering your blood lactate concentration.) Lactate does not cause anything, and injections of lactate into the bloodstream will not produce any effect. Noakes describes this well and fully in chapter 3 of The Lore of Running.

Unless you know your body very well, heart rate is not an accurate determinant of anything, much less lactate level. Heart rate varies considerably at the same pace due to many factors. My heart rate on a second daily run will be much higher than on the first run. (at the same pace) It will also be much higher in a race than on a training run. It will also be much higher if I have a respiritory illness. Nevertheless, the actual energy consumed by running at the same pace under the conditions above will be the same. So if you rely on the same heart rate on a bad day your physiological response in terms of lactate will be very different. By the way, there is a BIG difference between 2.5 and 2.9. That's almost 20% higher.

I am not suggesting lactate testing is a waste of time. Not at all. I am simply saying that one number does not fit all runners. If you want to take the time to measure your lactate levels at various paces you will get a good idea of your turnpoint, and also of what pace you should be able to hold for a marathon. The curve you develop will be different for most runners though.

I still think it is easy to learn your turnpoint by doing a few runs on the track.

mcsolar99

1,018 posts since
Aug 14, 2007

13. Nov 23, 2007 9:34 PM

in response to: yacky

i've run several marathons according to a heart-rate plan, or tried, and still managed to bonk. as noakes points out, there are some of us who have low liver storage capacity for glycogen. and running out of liver glycogen was the source of my marathon bonks. my limit seems to be at 2 hours at marathon race pace (pr currently 2:58, but heading lower, i hope).

my bonks were pure liver glycogen depletion... i would be operating easily, well below threshold, and then get dizzy, some tunnel vision. after about 10 minutes as my brain and nervous system burned through my blood glucose supply, i'd be forced to stop and walk. it happened in three marathons over two years, and i was extremely frustrated. i just wasn't ingesting enough carbs to replace my liver supplies. muscle glycogen supplies really had nothing to do with it, as i could resume normal training fairly quickly, since each bonk turned into a hard 18-19 mile training run, followed by a 7-8 mile run/walk saga.

now i've run two marathons taking gels every 30 minutes or so, and no bonks. in the first attempt, i actually sped up significantly for the last 8 miles, from 6:55 to 6:35 pace, after i realized i wasn't going to bonk.

i think there isn't a connection between bonking and lactate levels. judging from my heart rate and post-race feelings, my lactate levels were very low after the bonks, compared to the successful races.

my guess also is that lactate levels climb significantly during the course of a race... and while the average may be 2.5 mmol, i've finished feeling like i had levels well above 4, like the end of a shorter race or a track workout. judging from the race heart rate plots that janssen shows, the increasing heart rates support the idea that lactate levels also increase.

yacky

15 posts since
Sep 20, 2007

14. Nov 23, 2007 11:17 PM

in response to: yacky

I believe my MHR is about 182....

2.9 might be a lot higher than 2.5 but in the tests I have run on myself it doesn't take much of a change in effort to move from 2.5 over 30 minutes to 2.9 over 30 minutes. I cannot even pace myself/control conditions enough outside to measure this accurately. My body seems to zoom to 6.0 mmol fairly easily and then just hold there for a long time.

I would think that on a second run your heart rate would be higher than on your first since your body is tired and more effort is required to maintain the same pace. This is why I think HR works, it adjusts for other conditions.

I must admit I like the idea of testing at a "slow" marathon pace 30 minute run the week before a marathon while I am tapering rather than run 1 hour hard on a track to find my optimal marathon pace. Wouldn't you like to be able to find your best pace within a couple of minutes the week prior without running a full out race?

I think the 2.5 is fairly standard because it is just above baseline however, people's lactate threshold may vary quite a bit from 4.0 to 7.0 where they can run for an hour. So, using a lactate test to find where your lactate takes off is fairly time consuming since the number means very little but the rate of change in the number is everything. (It also involves a lot of poking.)

I would expect that taking gels would allow a runner to run a marathon at a higher mmol.

Does anyone have a "mass" of lactate data from marathon runners? I think the telling number would be the level at the halfway point with split times....

Has anyone else tried this on themself?

I must be fairly standard since it describes me fairly well....

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Nov 19, 2007 6:37 PM

Lactate Testing - Marathon Pace - Heart Rate

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