HR Information, interpretation please.

I'm learning about HR zones too...but what I have heard is that your MHR and zones for the bike and the run are going to be different.  You shouldn't use the test for one activity to determine your zones for another activity

Yah I know. I was told run is 5-10 beats higher than bike.

Phil

Phil,

Here are a few reactions.

It is entirely possible for your bike LTHR to be higher than your run LTHR.  For individuals who are trained about the same in both, this is unlikely -- their run LTHR will be higher, in general.  But if you are more experienced on the bike than on the run, then your tested run LTHR could be lower.

When you say "LTH 2x20 and I had 172 and 168 for each 20 minute session" do you mean that those were your averages?  Did you warm up before each one to get your HR up a bit first?

Most LTHR tests will have you going all out for, say, 30 minutes, but only take the average HR for the final 20 minutes.  If you take the average for the entire 30 minutes, then you are including a lot of time where your HR is just working its way up.  So unless your HR was already elevated (due perhaps to a warm-up with some intensity to get the HR up), the 161 average on your 5K is probably LOW as a LTHR.

In general, I'd say:  do a careful LTHR test for both run and bike.  (And indoor bike can be different from outdoor bike as well...)  The protocol on BT is a good one, IMO.  There are others.  How do the results relate to training?  They can be used to determine training zones.  (I know you know this.)  A lot of plans here and elsewhere will specify the intensity of a given session (or portion of a session) by zone.  You can plug your LTHR into the calculator here on BT to get your zones, or use one of the standard formulas (such as Friel, but there are others, generally expressed as ranges of percentages of LTHR).

You can certainly use all of these numbers to GUESTIMATE HR training zones. It's a starting point. But the best idea would be as Experior said...to conduct established, repeatable protocols for both bike & run training.

THe HR numbers are actually a little confusing to me. If you averaged 170 bpm for the 2 x 20 bike workout (were those all out?) but only reached a max HR of 171 for your 5k on an indoor track...that doesn't seem consistent. While your 5k time isn't smoking, you are running. running engages more muscles typically than cycling does, so your running HR should be higher in general for the same "effort" level as compared to cycling.

Unless your cycling fitness is simply that much better than your running fitness.

Heh, I accidentally started an argument about HR/LT testing in another thread.  The suggestions here to pick a repeatable test are good.  I think the debate as to how precise HR/LT is or should be is more relevent to higher performance athletes.  As you (and I) progress, more refined training data would become more important. 
By the way, 88lbs off is a darn good job!

Oh yeah, Let's Go Bluuues!

its been said above already but what i have noticed since i just performend 3 LT HR tests.

all 3 were 50 min, 10 min warmup, 30 min tt test - after 10 min hit lap and 20 min all out, 10 min cd.  20 min is your LT.  this test is good because all 3 times i was fairly close which means i am confident with the LT HR. 

also my bike LT was about 3-5 beats below run LT.