Tuesday, March 14, 2006

HRMMMMM...

Very interesting. I have the heart of an old man apparently. My max heart rate test turned up a 176. That is much, much lower than the 192 that I had been determining all of my percentage efforts from. So that is good news. Another bit of good news is that I did not often let my heart rate monitor determine how fast I run. Maybe two or three runs in 15 weeks. I run how I feel, but I like having the data to get a consistent objective set to correlate with how I'm feeling. Plus I'm just a gadget dork.

Now I can look back at those 1450 miles over the last four months and feel very good about the effort levels. Before I was very concerned because it felt like I was working really hard on most of my runs, but they were coming out to be less than 70% percent of what I thought was my max HR. So then I would get frustrated and crank out a long, hard run and maybe get 74-75% max HR average, but then be totally wiped out for two or three days. Well, that 75% at 192 turns into about 82% of 176, which is pushing into the mid-range of a good, solid LT working zone.

I found some information that might explain why my max HR is so low. I know that 10 years ago, it was at least 200. Turns out there is some evidence that it can change dramatically based on your conditioning. I found this on Pfitzinger's site:

You can accurately determine your max HR during a hard interval session. An appropriate workout is to warm up thoroughly and then run 3 high intensity repeats of 2 to 3 minutes up a moderate hill, and jog back down right away after each one. If you run the first hill at 90% effort, and then run the last 2 all out, your heart rate should reach its maximal level during the 2nd or 3rd repeat.

Interestingly, there is evidence that max HR changes with an individual’s aerobic fitness. Your max HR decreases when you make large gains in your cardiovascular fitness, and increases again if you have the misfortune to go from being very fit to out of shape. An untrained person may experience a 7% decrease in max HR with training. As your max HR changes, your heart rate training zones may need fine-tuning. If you have substantially increased your level of training you should test your max HR every 6 to 12 weeks to check whether it has decreased. Similarly, if you have had a prolonged break from running, you should check your max HR because it may have increased during your time off.


I certainly should have made large gains in my CV fitness, so this puts my mind at ease. I will definitely be making the max HR test a more regular part of my training, as well as the Hadd type testing. The information is invaluable to progress, which is what we are all after.

By the way, the max HR test is a BITCH! Fifteen percent incline at 7:30 pace is brutal.

5 Comments:

Blogger Mike

Great news on the heart rate, and as an added bonus, treating your treadmill to enough of those 15% grade efforts might mean you get to buy a new one! Seriously, it's interesting to see these results, it really does bode well for fall. Just make the build-up last.

3/14/2006 08:51:00 PM  
Blogger Zeke

Hey, if nothing else, the HRM talk got you posting left and right.

Your 176 HRmax doesn't surprise me based on other info you gave. I didn't want to come out and say it the other day, but there was no way your max was 188. If it was, you wouldn't have any problem getting into the 140s and 125-135 would've felt like an absolute crawl.

3/15/2006 12:02:00 PM  
Blogger Eric

Yeah, I don't know why I was so slow to realize my max HR was just low. I guess I had it in mind that I should have been a lot closer to the old 220-age number than I am.

I need to post more. Unfortunately, by the time I have time to write an entry each day, I need to get to sleep so I can get up for my next run. It's a vicious cycle.

Thanks for the comments, guys.

3/15/2006 08:42:00 PM  
Anonymous Sasha Pachev

Eric:

I thought you would find my data interesting/useful. In 1998 (age 25) I had my VO2 Max measured at 66. My best marathon time was 2:39:48. My max heart rate around that time was about 186, and I could race a half-marathon at about 168 (90% of the max). In 2004 (age 31) my best marathon time was 2:24:47, my max heart rate was 170, and VO2 Max measured 75.9. My heart rate at half-marathon race pace became 162, (95% of the max). My half-marathons also became more miserable - in the past I could kind of look at the scenery and think thoughts. Now nothing else exists except the mile marks, splits, taking tangents on the road, and the nearest competitor. I go into a different world for the duration of the race. Marathons, however, became more pleasant - the pace does not hurt, and they last less.

Another intersting observation - felllow runners have commented that the visuals of my running form have improved. However, the comparison of aerobic metrics and the change in performance suggests that the essence did not - I improved because of a stronger aerobic engine, and am still wasting lots of fuel somewhere. If I had even average economy, I would be running a 14:00 5 K (my best is 15:37) and 2:14 marathon instead of 2:24now.

220 - age or whatever formula you use for max heart rate is just a simplified mathemetical model of a semi-educated guess.

3/16/2006 11:04:00 AM  
Blogger Eric

Sasha, I wonder if the aerobic/anaerobic balance is like a teeter totter. Does too much aerobic work affect one's top speed? I tend to think so based on how I felt at sub 6 pace after 15 weeks of 7:20+ work.

I would suggest that your form economy is probably ideal, but that your anaerobic system is very underdeveloped and your neuromuscular economy is poor at sub-5 minute mile type paces.

I cold be completely wrong, but intuitively that makes sense to me. It would also answer the question of what happens if a person were to just build up at base aerobic paces for a long, long time.

I haven't yet looked at your past running logs, but when is the last time you ran a set of 4-6 sub-5 miles? Your PRs indicate you should be able to with ease. Relative ease that is...I know it's never easy!

Thanks for sharing. Your data is incredibly interesting, and spans a long time as well. Good stuff.

3/16/2006 12:35:00 PM  

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