Wednesday, June 4, 2008

heart rates are funny things

I went for a run last night (yay me!) And I decided to do some intervals my way (not an official HIIT day so I don't have to walk, take that!) and basically just jog but then throw in some sprints. Ok great. But guess where my heart rate would end up, 95% of MHR!!! And I'd only give it an 8 or a 9 on the RPE. Though I do fail the talk test miserably. I didn't upload my garmin so I don't know just how many beat per minute that is, (dumb that it only shows me % on the screen, I didn't see BPM anywhere, but on the computer it shows it). But if it does the 220- age for MHR, that puts me at 194 for max. I'm not sure how the 95% works, would 0% be 0 BPM or is 0 just my resting heart rate? I gotta wear that thing when I'm sleeping and learn more. So since I don't know resting heart rate, I guess i'll pretend that 0% is 0 BPM, meaning 95% is 184 BPM. Ok I believe that. I know I've been up to 180 before according to hand sensors on cardio machines (if that's accurate). Plus my max heart rate could be higher than that 220 minus age thing. I heard that was just made up anyway, totally random.

But it's just weird that it showed me at 95% of basically what should be my maximum exertion, and I still felt pretty good. Like I had more in the tank (and more than just 5%) I wasn't sprinting my fastest or anything. And on the slower regular running parts, my heart rate only went down to like 85% (164 BPM). And I felt like it was maybe a 6 or 7/10. I've heard workouts and stuff where the max you're supposed to get to is like 85%.

But like I said last time, need more data! Then I can possibly calibrate my sensor so I know the RPE for each HR% and vice versa.

oh also, I checked out the macmillan running calculator or whatever to see how fast I should be running my 10K this weekend in, based on my 5k performance....49:39. I can tell you that a sub 50 minutes is not going to happen! I'm guessing that the tri run wasn't a full 5K. I didn't wear my Garmin for it (my transitions were already slow!) so I can't check. But still very cool.

Edit - I just found my "resting" heart rate. It's approximately 54 bpm (that would not be sleeping, that would be sitting at my desk). Which according to this site is the lowest for a female athlete. (the lower the more in shape I believe). So that's good. But what a wild range I've got!!! And according to this site my max heart rate is anywhere from 188-195. So my 194 is appropriate. So based on my extensive expertise in fitness training and heart rate monitoring, I think that getting up to a really high heart rate, but still having a low resting heart rate, means I'm super awesome. Athletic wise that is. Objections?


eurydice said...

Your resting rate should be anywhere from 55-75 I think... depending on a variety of factors. My target rate is 125-165 and it's very rare that I go over 165 - only at the end of my runs when I'm pushing it fast up a hill or something... or when I run up the stairs of my building to the 10th floor. There is lots of info online about heart rates :)

Jen said...

*laughs* I am definitely still trying to figure out my target and all resting HR creeped me out at first (not as low as 54 obviously but to think of how fast it goes!)

I usually reach about 175 - 180 when I am "running" on the eliptical and DEFINITELY in step class but I tend to jump around and stuff the whole class (thought it doesn't STAY that hight the whole time).

Um, but yeah, I think that does mean you are pretty friggin awesome!

sherijung said...

I'm just going to copy here a portion of what I found at the FIRST (Furman Institute of Running & Scientific Training)website:

"FIRST is familiar with 8 formulae, with supporting research, that estimate maximum heart rate (HRMAX). Knowing which formula to use can often be as tough as throwing darts in the dark (not recommended). The most commonly used formula to estimate maximum heart rate is HRMAX = 220 - age. However, the 220 - age formula may not be the most appropriate for all runners. In fact, there is more research supporting some of the alternate formulae for HRMAX than the 220 minus age formula.

Researchers have discovered that age-based heart rate formulas can be as much as 20 bpm off of actual maximum values. Using the "wrong" estimated HRMAX to base your training can lead to slow development and ineffective training.

Dr. Robert Robergs, a researcher at the University of New Mexico who has done extensive work on this topic has concluded that there is no acceptable method to estimate HRMAX. Therefore, we prefer that runners focus on maintaining pace rather than heart rate. In a race, you will not be running the same speed at the same heart rate throughout the race. Cardiovascular drift, due to increased heat storage and fluid loss, will cause the heart rate to increase as running time increases. If you rely solely on heart rate, you will be running slower at the end of your workout as your heart creeps higher. That's why it is difficult over the last part of a race to maintain the same pace; that is, you have a higher heart rate for the same pace. It requires more effort to maintain the same pace. We feel that you need to practice that in training so that you are able to tolerate that in a race."

Randi, I've been using a Polar HRM during my running for the past year, and find a lot of truth in this, especially the part about cardiac drift at the end of a long workout. I've found the HRM most useful in understanding my own body's reaction to exercise at different perceived effort levels. Rather than focusing on what HR levels someone else says you should work at, play around with it and use it to do research on how your own body works while exercising. I'm sure there is some way to get your Garmin to tell you your actual HR instead of the percentage of HRMAX.

There is also a way to get really close to your actual HRMAX (outside of going to Dr for a stress test), by running all out for a couple of minutes after a long warmup.

I actually don't use my HRM much anymore, but using it helped me trust my ability to judge my perceived effort, especially for tempo runs and races.

Angie All The Way said...

Damn you Garmin bitches! :-P

You are pretty kick ass though - believe it or not, I think you fall in the "athlete" category regardless. You did just run your second Tri!