Unstable HR

by Siri Emilie K. Strandman
(England)

Unstable heart rate :

"Hi Marius!


I have just finished the second week of this program and I have a question about HR as this is what I chose to run on.

Running in EZ 3-5 is okey, but zone 1 is my main problem. My HR is apparently very unstable, and even if I run on a treadmill so the pace is the same my heart rate is jumping up and down (mostly up). Today when I started running I had a heart rate on more than 160 (I have a max of 195), and this lasted for several minutes until it lowered and came down to around 140. But after it normalises it still jumps up suddenly, or down.

Should I adjust the speed on the treadmill all the time, so the HR is in the correct zone? Then I sometimes would have to walk.. And when I run outside, I have to pay attention to the HR very often to make sure that its not too high or to low. I have still not managed to do a zone 1 run in zone 1. It always comes up to zone 2, even if I run very slow. This makes me stressed, as I don´t want to walk the 1 zone runs... (When I run I do feel that it effort-wise is in zone 1)

Do you have any advice for my uncontrollable heart rate??

Thank you,

Siri Emilie"

Answer: Hi Siri and thanks for your question.

Now, the main reason why this happens (particular on the treadmill) is due to cardiac drift. It happens more often inside on the treadmill, due to the heat factor - which makes you sweat more and therefore get a heart rate increase due to this.

I would do the following :

1) check that the heart rate belt is properly placed and that you have enough water in between the belt and the skin before the workout - this decreases the accidental variation of heart rate due to technical problems, which is common especially at slow speeds.

2) on the treadmill, until you are in even better shape (it does get easier and more stabile with better overall shape!), allow yourself a somewhat drift into zone 2. This is ok, especially when done indoors, due to the cardic drift :)

I wish you all the best,

kind regards,
Marius