HR during racing: data from the field

Bump.

I've read that if you bust a nut in a 5K, all-out kick at the end, you'll get pretty close to max HR (it's a suggested alternative to a standardized test).

one thing the original poster should be aware of is that HR is not an exact correlation to VO2max. So when you say, you sustained 95% Vo2max for 34minutes, you didn't. You sustained that HR. The Vo2max could have varied widely from that #.

The thing about using a heart rate monitor is interpreting the data correctly. HR is affected by many things.

The only reason heart rate will change during a given time is because a change of pressure. The heart is a slave to central control which purpose is to maintain blood pressure.

When metabolic rate increases during exercise (an increase in running pace), the control mechanism increases cardiac output. The regulation of blood flow is important so blood pressure can be maintained.

Running in hot and hummid enviornments increase metabolic rate. Studies have shown that above 70 f (21c) heart rate submaximal intensity will increase about 1 beat/min per degree F increase in temperature. Oxygen demand does NOT increase in the heat, but thermal stress does (core temp.) The cardiovascular system must use the blood to provide O2 for energy metabolism and skin for evaporative cooling.

For marathon running for every 7f increase above 55f, you will slow down 1 minute.

This heat produced cannot accumulate, but must be removed. For the same reasons, a higher relative humidity will increase heart rate because of decreased ability of the body to use evaporation as a mechanism for cooling and keeping core temp at optimal function. The body must increase blood flow to adjust.

The reasons why you had a higher HR than the numbers you discribed is because the heart has to work harder to maintain pressure because of blood flow to the skin and muscles.

I have run 5k's in the heat and my avg HR was 99% in 80f, and in 50-60f it was 95-96% maxHR.

I have also run several half marathons at an avg 92% in 50-60f, but recently ran a 20k in 80f at an avg 96.6%

The cardiovascular system has to adjust to the enviornment. It isnt a suprise that world records and personal best are run in cool temps.

KudzuRunner wrote:

What my experiment suggests is:

1) That going out to hard is a bad idea because he brings you too quickly and too far above threshold, forcing you to slow in order to stabilize a too-quickly-rising HR. I normally run my tempo runs at 7:05 - 7:10, but at a HR of 177, not 188. The fast first mile--which didn't feel that hard, frankly--forced my body to work that much harder for what should have been a hard-but-comfortable tempo pace, not a race pace

Please continue to collect data on this matter, as this is potentially a revolutionary finding--that going out too fast makes you slow later. Good thing you wore the monitor to unearth this!

Bump.

Well, I figured I'd tweak those here who seem to think that Dave Bedford beginning the 10,000 final in '72 with a 60-second lap was a smart, gutsy way to run.

Or that Pre was onto something.

Seriously, SMD: I knew that YOU know not to go out too fast--you're obviously a cautious, prudent guy (or girl), but there are a lot of young guys posting here who don't.

Bump....starting too fast?....used to be the bane of my racing career.

just wondering are you 22 years old because your max HR is supposed to be 220 subtract your age

rivas wrote:The thing about using a heart rate monitor is interpreting the data correctly. HR is affected by many things.

Definitely true. There is as much art as there is science in understanding what your HR is doing, and you have to learn by experience.

In my experience, the following things affect what your HR will do on a given run, in rough order of importance (give or take):

- how fast you are running: this one sort of goes without saying I would think. The relationship between speed and HR is not linear, though.

- how long you have been running that fast: your HR will generally rise over time at constant pace.

- your actual current maximum HR: this limits how high HR can/will get during any given run. HRmax can change a little (drop) - say 5-10 beats - with training (or rise with de-training).

- your level of aerobic fitness: the fitter you are aerobically, the less drift you will see.

- weather conditions: if it's hot and humid, your HR will be higher for the same perceived effort, and maybe higher for a slower pace. I often need to slow 30+s/mile if it's very hot and humid if I want to see the same HR as on a cool day.

- your state of fuelling: if you are low on glycogen, HR will be lower, all other things being equal. This one seems counterintuitive, since you perceive you have to work harder to maintain the same pace as when well-fuelled, but it's a real phenomenon. If you run out of glycogen during a marathon, your HR will GO DOWN during the race. I know, that seems wrong, but it is correct.

These factors are interrelated, so it can be hard to decide what's more important at any particular time, but with experience, you can learn to read the HRM numbers fairly well.

Lemme know if you want me to dredge up some of the HR data from the earlier race distance vs. average HR discussion we had. We did look at HRs for shorter races.

Good stuff, thanks for posting.

In my experience, Rivas' post rings true. HR will run higher at race pace on a warm day due to increased blood flow to the skin in an attempt to cool your core. For a moderate distance race, you may well be able to sustain about the same pace you could on a cooler day. I think that is the effect you are observing in '2' relative to percent of maxHR.

As has been pointed out environmental conditions affect HR a good deal, The % of max values that you showed look much more like %VO2max values, not %HRmax values and HR is almost always at a higher fraction of max than is VO2. What I've seen says when racing a race that lasts about 30 minutes (whether a 10k or an 8k for a slower person) you are at about 93%VO2max and that could easily be 95 or greater % of HR max. Same with the longer distances you refer to -- around 88% VO2max (90-92% HR max) for threshold pace (about 1-hour race pace), and mid-(even upper)80s% when racing for a couple hours

This is a re-post of some data for various distance races for a number of different athletes. The next post will summarize these numbers as averages:

Here are a bunch more individual data for 12 different runners of different talent levels and different levels of aerobic fitness:

Runner Distance (km) Time Percent HRmax

A 5 0:16:18 95

A 5 0:16:20 94

A 21.1 1:13:43 96.2

A 21.1 1:12:55 95

B 5 0:16:08 94.3

B 8 0:28:36 92.8

B 10 0:34:06 93

B 10 0:33:46 95.2

B 21.1 1:15:03 94

B 21.1 1:14:58 93.1

C 5 0:16:12 93.1

C 10 0:26:20 93.8

C 16 0:34:25 93.8

C 21.1 0:57:44 90.7

D 6.4 0:22:54 95.3

E 21.1 1:25:21 91

E 21.1 1:29:37 86.3

E 21.1 1:27:40 90.4

E 30 2:12:56 85.5

F 12.9 0:52:34 85.4

F 15 0:59:12 86.2

F 17.7 1:11:46 83.3

F 21.1 ?? 82.5

G 10 ?? 92.5

H 5 0:16:45 95

H 10 0:33:41 94.2

H 16 0:57:50 93.7

H 21.1 1:16:54 92

H 21.1 1:13:40 92.2

I 21.1 1:28:43 91.7

J 5 0:15:12 95.3

J 12 0:39:44 96.7

J 16 0:52:26 90.7

J 21.1 1:10:42 96.4

J 21.1 1:11:44 94.8

J 21.1 1:10:30 90

K 21.1 1:10:50 91.6

K 21.1 1:15:58 90.4

L 5 0:19:40 92.3

L 21.1 1:30:08 89.9

I'll post up the averages for each distance as soon as the spreadsheet spits them out for me.

Another repost from the earlier HR discussion thread:

"Sorry about the format - that looks pretty ugly. Anyway, if you take the average for the race distances with reasonable sample sizes, you get:

5k - 94.1% of HRmax

10k - 93.7%

10M - 92.7%

HM - 91.6%

As you can see, there is plenty of scatter about those means, but nevertheless there is an overall relationship, and the trend is toward the 87-90% we already saw for the marathon results."

Pete wrote:

Lemme know if you want me to dredge up some of the HR data from the earlier race distance vs. average HR discussion we had. We did look at HRs for shorter races.

Pete:

Great post. Many useful clarification.

Yes, you had a lot of interesting data, but back then I was only focusing on marathon distances/HRs. I'd be very curious to see what the data shows for 5/10K and the like.

Never mind the previous post; you've already posted the info. Thanks.

The operative point here is that the % of max HRs that you've come up with, based on a lot of data as they are, are for that very reason something that any individual runner--be he a 13:30 5K guy or a 20:05 5K guys--should take with a grain of salt, since a sustainable HR % for 13 minutes obviously might not be sustainable for 20 minutes, if we're talking about two skilled, hard-racing runners of two different talent levels. If I understand your data, you've in effect averaged their two 5K HRs. The faster guy might have averaged 96+ %; the slower guy might have averaged 94%. This variance due to race-duration for runners of different talent levels may account for some of the confusion that I believe accrues to such HR-at-race-pace data.

For distinctly midpack 10Kers, for example, who are running for 45 minutes, 92% of HR max might hold true. For elites running the same distance in only 28 minutes, 95+% might be the standard.

Correction:

The fast 5Kers might average 95%; the slow 5Kers might average 93.2 %. That would produce your 94.1% mean.

I'll stop beating this dead fish, since it's beginning to shred in my hands!

KR,

I think these HR data are interesting only from the perspective of looking back and trying to understand things.

I think it is a very BIG mistake for someone to try to use an HR number as a guide for pacing in a race.

Kudzurunner, what awards do they give out for highest heartrate? Lowest heartrate? I thought so.