Monday, 3 December 2012

Back on the running and Cardiac Drift

Last night I went out for the first run in over a week after resting my left foot after the dreaded TOFP (Top Of Foot Pain) and I'm delighted to report that it was a complete success!

Not only was it a good long run, but I'd aimed to run for one and a half hours and that's what I did. 8 miles, which isn't fast, but that wasn't the point. Also, running in the pitch dark along a country path beside a stinky marsh at high speed isn't the best advised course of action (though it was fun to do it on Halloween while listening to the "Zombies, Run!" game/app - which is excellent btw).

Here's the mapped run, so you can see where I ran to (Gravesend to Chalk and back) and below is the image of my heart rate as I ran (click to enlarge)

My heart rate for a run showing cardiac drift

Cardiac Drift

Interestingly, you can see how my heart rate increased towards the end of the run. Nearly all my runs have this and from what I've read it's something called cardiac drift - where for each 1% we lose in bodyweight through sweat etc. our heart rate goes up around 7 bpm. That said, I'm not sure that this would account for all of the increase so it's definitely something to watch.

Apparently, cardiac drift is caused by a thickening of the blood as we lose blood volume by water loss. It just shows how important maintaining good hydration through a run is.

In yesterday's run, I filled up my bottle of water and then... Left it by the front door as I wrestled with keys, earphones etc.


Normally, this would have killed my run 20 mins in, but as I was taking it so easy and the fact that it was -1C outside, I actually didn't sweat very much and didn't really start thinking about water until the last 20 mins or so.

Of course, today, my hip-flexors are sore and I've given my feet a couple of massages, but it's all "sore" as opposed to "hurting", so it's all good.

It's a rest day today (part of the plan) and will be back on it tomorrow. Oh, no wait, it's Monday. That means I've got Bodypump tonight at Meopham Gym.


Can't beat a bit of cross-training to keep me fit and maximise my endurance and strength for the run. It'll also be wicked to stretch out those hip-flexors.


  1. I never bring water with me. Did 2 hour run without a sip. That would explain the headache I got an hour later!

    1. Ouch! Even if I'd drunk loads of water when I got back, I'd probably still have a splitter.