Higher Heart Rate When Running With Partner??

Hi ladies!

I have noticed a strange and annoying phenomenon, and I'd like to know if others feel the same way.

When I run by myself I have a lot of control on my heart rate, and can keep it, say, between 165 and 170 on flats (my max is 200-something). However, if I'm running the same course with my running partner, I run at the same pace most of the time, yet my heart shoots above 175 quickly and just stays there, and goes back there after taking walking breaks (on 10K+ runs). She and I are similar runners, I'm perhaps a little bit faster, especially going up hills (she's faster on the downhills),

The pace is very similar but the time is usually different: if I run with her it's more likely to be at 7am, while I run by myself towards the end of the day. Could this be the cause? Are we maybe taking a faster start and my body reacts to that negatively? Any ideas?

I find this a little annoying because those 5 to 10 beats per minute make a difference at the end of my workout. Any clues?

Grog,
I am sure more experienced runners will have better answers. For me, I usually run at night. I run the same route and when I run in the evenings I keep everything nice and even. When my routine must deviate, due to life, and I must run in the morning, I notice everything is slightly off kilter. Could be something to do with body temp, HR, and balance during various parts of the day?

Grog,
I find that to be true for me, too. I think the problem for me is that when I'm running with a group, or another person, we talk. Talking causes my HR to be at least 5-10 beats more per min. than when I'm alone (or at least quiet). I don't know why (working harder to keep talking while not focusing on breathing?). Also, the time of day could certainly be a factor. I used to run at 5 am, but have found that I'm much more "warmed up" after a day at work, and have a better run in the evening when I've gone through an entire day (even tho I may be more tired from the day's work).
Strange, huh? I wonder if anyone else has any concrete reasoning for this.

Tri girl is right! Talking will increase your heart rate. When I had fitness testing done with my personal trainer I couldn't talk while doing it, I had to point to a scale because he didn't want my heart rate to be thrown out of wack!

As for concrete evidence of why that is... Can't back it up with anything, Except maybe you'e using more oxygen so youre heart beats faster to accomodate. (breathing rates do increase when you talk)

Great explanation ladies, thanks!!!

I think the talking thing is it, plus a minor factor being the time of day. Nights are definitely easier for me...

I guess it's good nonetheless to train in the morning, because races tend to be in the morning, not at 5pm!!