Cardiac Drift?

1. Cardiac drift - yes.

2. How to minimize - Run more, build a bigger base.

3. Not on the bike - Not riding long enough to notice it.

Everyone gets cardiac drift.  Pro to beginner, everyone.  The more you train, the longer you can hold it off.

Exactly.

This same thing happens to me and it has gotten me to go out to hard to soon.  When you start your run it will take a while for your heartrate to get up to where it should be at the effort you are running.  If I want to run at around 160 BPM I'll start off at around 154 - 155, and after about 10 min my heartrate will gradually get up to 160 and stay there.  I think that it takes a little while for your heartrate to respond to the effort and your body to warm up.  You definatly don't want to get up to your target HR in your first 5 min if you want to maintain that pace.  If you do you will end up running way to hard and you will have to keep slowing down to keep the HR where you want. 

That said, for longer runs if you don't have a really good base built up your HR will be steady for most of the run and when you are getting beyond your comfortable distance limit at the pace you are running your HR will drift upwards.

Did a LOT of bike trainer Spinerval workouts over the winter and cardiac drift was mentioned as a relation to hydration.

Do you maintain good hydration throughout the day??  Lots of water??  If not, perhaps that may be why your HR is creeping up so early in a run.

Just my chump change worth of thought.

Thanks everyone for all of your responses.  I am inclined to think that it is more of a hydration thing than a training thing.  Earlier in the year, I was running as far as 7 or 8 miles at a stretch and it wasn't much of a problem. Now that I'm running in the 90 degree heat with 50-70% humidity, it is becoming a big issue. 

 Granted, I haven't been running as much lately as I was back in January, but I have been running.  Surely I wouldn't lose that much of my base that quickly. 

As for hydration and pee color, I do my best to stay hydrated throughout the day, but I could always do more.  Shortly before my brick today, my pee was clear-ish, but at the end of my run, it was somewhere in the middle between clear and flourescent yellow.  I didn't weigh myself before, but I would estimate that I sweated out about 3 lbs. 

Drift happens!  When you get hot the body is trying to pump a lot of blood near the skin to cool off.  Last week when it was 69 and very low humidity, I ran home in the late evening and was hardly sweating and had no problem keeping my HR in mid Z2.  It took 40 seconds to get into Z1 during the warmup.  Last night it was 79 & humid and I ignored the HRM and went with a RPE run once I warmed up, took only 17 seconds to get into Z1 on my warmup.  BTW I live in FL.

Go with your RPE when the conditions are like this, Mike Ricci posted this to me awhile back:

"Use the scale Ron copied - that's what I use as a guideline. Learn to use RPE and HR together. Some days (especially) hot ones, the HR won't mean much and you'll have to rely on RPE."

Don

I'm going contrarian here.

1) No.  10 minutes is not cardiac drift.

2) More base training, and more heat adaptation.

3) Better bike fitness than run fitness.

You shouldn't be running close at LT for the majority of your training runs.  I do majority of my runs in zone1 and zone2 for base.

You body takes time to adapt to heat.  How long have you been running in the heat?  Are you properly hydrated before you start?  Are you hyrdrating properly during your runs?   

What is you running background? Your blog only shows 5 runs during April.  That's really not a lot.

I'm going to go with your HR going up due to lack of run fitness.  Run more, run often, and you should see improvement. 

unfortunately, I have been pretty bad about keeping my log updated.  Im on a streak as of late though, so hopefully I can keep it up this time. 

Here's a brief history of my running.  Several years ago, I was running quite a bit, but then due to work/personal schedules and sadly to say, general laziness, I all but stopped running.  I picked it up again a little over a year ago whenl friend of mine talked me into doing my first tri.  Since then, I have seen quite a bit of improvement in my run times, but there is also quite a bit of fluctuation in my performance.  Some runs, feel great and everything clicks.  I can maintain around 8:30 pace for five or 6 miles and feel great throughout.  On other runs, like I have been experiencing lately, I mostly suck wind as I watch my heart rate climb to a point that I can't sustain the pace anymore. 

Granted, I definitely need to train more in the running department, but I wondered what else might be causing the performance fluctuations. 

As for my training, what do you suggest?  More long slow runs?  More runs just below my LT?  Intervals? 

I agree here.  This is not cardiac drift.  You are probably starting out too hard.  HR is a lagging indicator so it takes awhile to catch up with the effort you are putting out.  Don't try to run 8:30/min if you're gasping 10min into your run.  Try running slower and, like coredump says, increase your base fitness.

Step 1: determine what your HR zones are now.

From there, develop a periodized training plan.  Start with base ( zone 1 and zone 2 ).  When you have a solid base, then begin to add intervals / speed work.

Your base work is the foundation, if it's not solid, then the rest of your "house" is shaky.

Focus far less on "holding pace" than on "holding HR zone".  Train your base, and the pace will come. 

Not to be a smarta$$ or anything, but sporadic running leads to sporadic performance. 

Train for short periods in the heat but stay properly hydrated with a sports drink (vs. plain water) and keep it safe.  We're talking zone1, no higher.  RPE 4 if you like RPE better. But the point is NOT to increase speed or distance...just to safely and gradually acclimate to the climate.

Long zone 1/2 runs but not during the hot part of the day.  If you are having trouble keeping your heart rate down then I see NO advantage to interval or near LT efforts at this point.  I can't see your original post, can't remember if you said you were actually uncomfortable or just watching your hrm.  But you need to be able to complete your desired distance without terrible discomfort before you worry much about your speed, especially if you are in a hot climate.