The Heart Rate Experiment – Part 1


Race season is over for me and I’m happy with my accomplishments – I ran two marathons and two half marathons.  I didn’t reach my goal of a sub-4 marathon but I set a new personal record for both distances.

I’ve decided to spend the summer preparing for next year, improving my speed and building a good base. But the biggest issue I need to figure out is the heart rate issue. I need to understand what happens to my body that makes my heart rate suddenly shoot up during some of my runs.

I haven’t been able to find any logical pattern or obvious cause to the HR phenomenon. During the Rotterdam marathon it happened after 20 miles and last week during the Tel Aviv half marathon it happened after just 2 miles. So I’ve decided to experiment. I will spend the next few weeks running with a glucometer, testing my BS every few miles.   I’m hoping to understand whether it is dropping blood sugar that triggers my HR to rise.

I went on my first run of the experiment this morning. I planned a 7.5 mile run split into three 2.5 mile laps, with a blood sugar check at the end of each. I planned on increasing my HR every lap by 10 heart beats per minute, starting at 135 and finishing at 155.

It was a surprisingly cool day and the run went better than ever. Many times my HR rises at the start of my runs and comes down within 5 minutes. Today my run went exactly as I planned. I woke up with 131 BS, had some coffee with milk and went running with my BS level at 164.

I ate my Halva snack (14 grams of carb) after 2 miles and tested my BS after 2.5 – it was 162. After 5 miles my BS was 175 and at the end of my run it was 162 again. I felt great, ran well and wondered if this was just a waste of test strips or if I would learn something from all of this.

For now all I can say is that running with BS of 160-175 on a cool morning seems to work just fine. But that is hardly a great discovery.

Notify of
Inline Feedbacks
View all comments
Copyright © 2009-2021 Diabetes Media Foundation, All Rights Reserved.
ASweetLife™ is a trademark of the Diabetes Media Foundation, All Rights Reserved.
Would love your thoughts, please comment.x