Okay, I really appreciate you taking the time to read this e-mail because I am a physician and I understand how valuable your time is.
That being said, there is some exercise physiology I don’t understand
about myself regarding anaerobic threshhold. First, I am a resident, so my own training is pretty intermittent and I am just beginning to consider training for some introductory triathalons. Anyways, I recently bought a Polar 720i and really enjoy using it. I am 31 years old, am 5’11", weigh 185, (pretty large frame) and have found my max HR while running to be 197 and while cycling 192. I attempt to train aerobically less than 170 and shoot for low 160’s. Resting HR is high 40’s low 50’s. Was in very good shape in high school and have become out of shape pursuing medicine. I am trying to get in shape again (have been for the last year with periodic mtn. biking, road cycling, and running) Thats my back ground. Here is my question. I ran my first 1/2 marathon today. The longest I ran before this was only 10 miles back in January. Since then, the longest was 8.5 miles about 1.5 weeks ago. I ran pretty hard (for me), finished at 1hr 54.
My average HR was 177 and I spent 1hr and 45 minutes above my zone (greater than 170) I hit 192 twice (this was the hospital hill 1/2 marathon in KC, the national championship). This is what I don’t understand, was I really anaerobic for that long? I honestly went above my zone after mile 2 and never went below 170. Are my zones off? I am following the basic rule of first physically finding my max HR and then applying the 80% rule–above is anaerobic and below is aerobic. Please be as scientific as necessary. We don’t learn about exercise that much in med school, but we do get a ton of physiology.
Again, thank you very, very much for your response.
Scott Rogers
SJRogers,
First, let me tell you I’m no expert or authority on this subject, but I have been active in recreational cycling for more than ten years. The last 2 years I have been working on improving my time trial performance, so you might say that I have started racing.
I can say this from experience, that as one becomes more fit, one’s AT begins to rise. I also suspect that your low resting heart rate has some impact on your AT as well.
My racing age this year is 52. My resting heart rate 54 bpm. My max HR is 178, not by some formula, but by experience. 80% of max would be 142 bpm. At that level I can go forever, provided I hydrate and eat. At the start of the cycling season my AT is about 153 bpm, or about 86% of max HR. This is the point at which if I go harder, I begin to blow up. As the season progresses and my fitness improves and I get stronger, my AT begins to rise and will level off at about 162 bpm, or about 91% of max HR. I suppose that if I worked at increasing my AT, I might be able to get it even higher, but only slightly, I suspect.
I found my HRM very useful at helping me to learn about my body as I exercise. I also quickly learned that the formulas that different people use to calculate max HR are usually off by some margin for most people and probably more so for most people who exercise regularly.
I would suspect that your AT is probably very close to 177 bpm, or 89.6% of your 197 max HR. This does not surprise me at all. You become anerobic at a heart rate beyond which you cannot sustain your effort much beyond 15 minutes without having to back off or blow up. This point is different for everyone, individual variation. It is also possible to train specifically to raise one’s AT.
Now that you have begun to discover what your max HR is and what your AT appears to be, you should be able to better define your zones based on your AT. This should help you to improve the benefits you can achieve through your workouts.
There are any number of books that can help you increase your understanding of your AT and training using a HRM. A couple to get you started would be: Sally Edwards’ Heart Zone Training by Sally Edwards. The Heart Rate Monitor Book for Cyclists by Sally Edwards and Sally Reed. And Precision Heart Rate Training by Edmund Burke.
I hope I have helped you some. Good luck.
agree with Ben that your AT (or actually in the context of your question, your lactate threshold heart rate) will change due to fitness. it will eventually reach a constant LTHR but with increasing fitness you’ll notice you’re going faster at the same heart rate or perceived exertion. really the best way to determine your LTHR is to test it instead of calculating it. for myself i use a 1000m swim, a 20k ride, and a 5k run (done on separate days!). since you’ve got your 720i then the average HR should be pretty accurate. use the 5sec sampling mode to increase accuracy. then calculate your zones based on the HRs you get. Joe Friel’s zones work for me.
on another note, what program are you in? i’m looking into residency in the US and was wondering how much time i would actually have to train.
Kim
Scott, try this: http://home.hia.no/~stephens/
Go to the exercise physiology basics section. It is written with a bent toward Master’s age groups, but, it is certainly applicable to Exercise Physiology in general.
One of the first things you will learn is that there is no such thing as aerobic and anaerobic…both process occur at the same time, even at rest…that’s why you have a resting lactate value, i.e., not all of the pyruvate goes through the Kreb’s cycle in the mitochondria, and that lactate leaches out into the bloodstream.
Another thing you’ll learn is that a steady-state sub-lactate-threshold effort (it’s a term with an agreed-upon definition you must have to talk sensibly about it) eventually results in exceeding your lactate threshold effort as the more efficient slow twitch fibers fatigue and a proportionally higher number of fast-twitch fibers are recruited to perform the work. These fast-twitch fibers aren’t nearly as “efficient” as the slow-twitch fibers in taking the pyruvate and running it through the Kreb’s cycle (they simply don’t have the mitochondria available in as high a concentration, among other characteristics), so, more lactate is leaching out into the cells as fast-twitch fibers are used more, and therefore the bloodstream reflects this with a higher lactate level.
There simply isn’t a “switch” from aerobic to anaerobic, these are just relative terms trying to describe an average of what is going on at the cellular level. Certainly, you can exercise above your Lactate Threshold for a period of time…that’s often evidenced by the sprint at the end of a race…it’s also evidenced by the slowing down (even at an increased level of effort) at the end of a race as lactate is accumulating faster than it can be cleared.
Anyway, visit that site, it’s really pretty well done.
Scott,
Setting up your training zones based off of just your max HR is not the best way to design your training zones. Either would be just “assuming” that 80% of that # (maxhr) is your AT. Off the top pf my head I can think of several coaches that would tell you that your AT can be anywhere from 78%-92% of your max HR. A better way of designing your zones is to actually find your AT HR. Fidning your AT HR, you will be better equiped at setting up your training zones and designing your training program effiecently.
Here are the two heart rates that you will need to find if you want to design your zones for HR. A heart rate when Anaerobic Threshold (AT) occurs. This can be done using a metabolic analyzer. A heart rate when Respiratory Compensation (RC) occurs or Max Vo2. This can be done using a metabolic analyzer. (Vo2 max testing)
Once you find these numbers, then you can create your zones. The %s are of HR @ AT. So if during the Vo2 max test, the analyzer detects your AT Vo2 at 46.6 ml/o2/kg/min and your AT HR is 172bpm, and your max is 51.7 ml/o2/kg/min with a max HR of 196bpm, you plug those HR #s into the below: **Zone 1: 75%-84% of AT or 129-144bpm Zone 2: 85%-95% of AT or 146-164bpm Zone 3: AT – 110% of AT or 172-189bpm Exception: if 110% is over Max- then use 105% Zone 4: **111% of AT –Max or 191-196bpm Using this formula I design training zones for my athletes bsed on their measured results. Every three months we retest (using my metabolic cart which utilizes the ventilatory equivalents or “V-slope” method for AT detection) and see if we need to make any adjustments in their zones as their fitness level changes. This takes all of the guesswork out of their training. Hope this helps, email me if you have any questions.
Rodgers to Rogers, AT is the number that counts.
I doubt that you could run for that long (half marathon) pushing HR that close to AT. It’s possible (the Kenyans can do it, and probably Lance) but not likely without drugs. But then you’re a doctor, aren’t you? (kidding)
AT is a measure of fitness, and can vary dramatically compared to MAX. Max is also darn hard to measure. As you get stronger, or your pain threshold increases, you might think your max has increased because you test better. Max doesn’t increase, because it’s max.
AT is a much more useable number, because it can help you avoid the most common error of newbies: training medium hard all the time. If you think you’re always pushing yourself, then you’re training too hard but not hard enough. A few years back, the Kenyan running coach disclosed his secret, and not everyone heard it. He said his guys crush the Americans because American (runners) do their easy workouts too hard and their hard workouts too easy!
Skipping the mumbo jumbo, a “close enough for government work” estimate of AT can be accomplished on a treadmill (set to 1.5% incline) by warming up and then jogging your way up to a pace where you begin to feel the effort, or about 80% of age rated max. For you, this would be about 150-155. Then increase speed by .1 mph every 60 seconds until notice a major change in you breathing. It’s called “sucking wind.” At the point where you first begin sucking wind, you’ve reached AT. You might run by this at first and not notice or not be sure, but the number you find will be ±2 beats, and that’s close enough for starters.
Oh, make sure you’re well rested before testing.
If you have access to a Computrainer, you can do the same thing on your bike, adding 10 watts per minute instead of .1 mph. Optionally, just subtract 5 beats from your running AT. Again, good enough to get you started.
Now use AT as the basis for your zones.
Zone 5 anything above AT
Zone 4 94-100% AT
Zone 3 89-94% AT
Zone 2 84-89% AT
Zone 1 below 84%
You should do one to three AT workouts per week during your building and peaking seasons, and NONE during base building. Build base by going long at the top of zone 2, then gradually work into low zone 3. Long runs are easier to control than long rides, so you might bend the rules on hills with the bike.
A good rule of thumb for an interval workout is to set a pace that will not quite get you to AT on your first effort, and a recovery pace that will get you to the top of zone 2 during your recovery interval. Then do as many repeats as you can, using the same two paces and the same time intervals until you can’t complete an effort. Then warm down and call it a day.
Retest your AT periodically, as it will increase.
When going long, avoid the temptation to finish fast. Sprinting at the end of a 2 hour base run can screw up all the base work you spent two hours doing. A great test of aerobic fitness can be performed on a treadmill. After a good warmup get to a heart rate of 90% of AT. Run three miles at this HR, clocking time for each mile. Change the TM speed if HR increases or decreases by 2 beats. You’ll get a slope from this where each mile will take a little longer. Each time you repeat the test, use the same HR, even if AT has increased. Only reset your HR for this test once a year. What you’ll see is that the slope should flatten, and the total time to distance should decrease. You can’t cheat on this test because, unlike a TT, you can’t just push harder. If you push harder, your HR will rise too far.
Jack Daniels has written some great detail on speed workouts in “Daniels Running Formula.” He gives running paces based on 5 or 10K race results. I find these work very well.