High heart rate - possible explanation

I have a fitness watch (TomTom Spark 3 with heart rate monitor) and I’ve used it for the last 6 months when cycling, walking, hiking etc. I now include running as part of C25K and to my alarm it reported a very high heart rate (bpm) for the first minute whenever I started the first run of a daily batch (although it settled down into normal peaks and troughs from the second jog onwards - but still a bit high). I felt perfectly fine btw and have no known conditions except age (61) and weight (bmi 31.5 - started SW this week!)

Research showed all kinds of alarming stuff but buried away in the detail were 2 items - infection and caffeine.

I have had a bad cold for the last 2 weeks but also start every morning with 2 mugs of percolated, caffeinated coffee just before the run.

Today I have no cold but also swapped my regular coffees for 1 mug of percolated decaffeinated coffee.

Wow- dramatic difference to heart rate - peak was 30 bpm lower(!) than before and average was 25 bpm lower. I blame the caffeine more than the cold and will not have it before runs in the future.

Had a caffeinated tea when I got back 😁

[UnfitNoMore Graduate]

Sadly I need the caffeine to get my eyes fully open 😂

[Hidden in reply to UnfitNoMore]

I didn’t tell my wife about the swap to decaf - she is probably asleep at her keyboard 😴

[UnfitNoMore Graduate in reply to Hidden]

😂😂😂

[ItstheMarchHare Graduate in reply to Hidden]

👩‍💻😴👩‍💻😴👩‍💻😴

[John_W Graduate]

Can you post a photo of the Heart Rate graph?

[Hidden in reply to John_W]

I’ll see what I can do - do you have experience of looking at them?

[John_W Graduate in reply to Hidden]

I plot my heart rate traces for the same runs and compare to assess my fitness levels And... it's obvious to spot any artefacts (erroneous spikes) in the trace - wrist based monitors often spike and can 'lock' onto your foot cadence. So if you're foot-striking at, say, 180 spm, then your HR might show as 180 bpm when it's actually 145.

[Hidden in reply to John_W]

I have managed to save the traces as a GIF or JPEG but can't paste them into the reply and can't even find the "User Help" section on this forum to see how!

My stride rate isn't tracked by my app (pace is) - it only shows an average stride rate for the whole session and it is 135/min so maybe a run could cause a peak?

[John_W Graduate in reply to Hidden]

You can only post images (Post Photo) if you start a new post/subject. Doesnt look possible when replying to someone. The peak won't necessarily be caused by what speed you're going - it could easily be a glitch by the watch.

[davelinks Graduate in reply to John_W]

Hi John, how's it going? been doing more excellent runs no doubt..

[John_W Graduate in reply to davelinks]

Hi Dave,

I'm very well thanks. I'm on the comeback trail after a 5 month lay-off after the London Marathon - the training and the race left me a bit broken (small tear in Achilles and a couple of infected toes and lost toe nails) and I needed the break. But I did NO exercise at all for 4 months and the fitness is now shocking - I'm way off where I was. But at least the Achilles seems fully settled now. Just been out for a gentle 10k which took exactly 60 minutes. Not bad.

How are you and how's your running going?

[John_W Graduate in reply to Hidden]

if you want to post and alert me you can simply @ me like this >> Hidden

So in your post you'd type somewhere @John_W

[davelinks Graduate]

Well done in doing the programme. Watches can do this sometimes, you feel OK? then don't worry about it, you're just doing c25k, so don't be concerned with heart rates and graphs.. only follow the times of the programme, slow and steady, that's all you need to do at the moment..

[davelinks Graduate]

Have found this blog, which may help, saves me explaining, see the link..😊

en.discussions.tomtom.com/s...

[John_W Graduate in reply to davelinks]

there we go... cadence lock. Had this issue with my TomTom Cardio Runner and recently with my Garmin FR 235. I've now bought a cheap chest-strap monitor and it's very reliable to far - no spikes at all.

[davelinks Graduate]

I've found the chest strap reliable on my old FR110, it's just that I can't turn the watch off! have tried everything regarding resetting so have to keep making sure the charge is up, have hinted about a new one from the wife for Xmas😁

[Hidden in reply to davelinks]

That explains it as it was mostly at the start of the first run. Thanks John-W and you for the good information.

Now I have to drink my way through a whole packet of decaf ground coffee - fortunately it did taste pretty good😋

[davelinks Graduate]

I was wondering if caffeineated coffee or tea was causing my mild headaches, but then think I'd have to drink a lot, does 12 mugs a day sound a lot? Thinking of trying decaffeinated..

[Hidden in reply to davelinks]

12 mugs a day would give me a headache, palpitations, twitchy eye syndrome and sleepless nights! - but it is down to how your body processes the caffeine so some people can handle it. I have heard you can get withdrawal headaches if you give it up and go cold turkey. I usually go more decaf as the day go by

[davelinks Graduate in reply to davelinks]

Sorry, 12 is wrong, it's more like 5-6 mugs plus some herbal teas as well..

[JumpingFrog]

Fitness watches are not that accurate, however you can get ones with a chest strap that may be helpful. If your worried see your doctor who will advise and reassure you. Don't dwell on it as that will lead to anxiety. Your fitness will improve as your muscles develop meaning you don't need to work so hard.