Strange HR reaction at first marathon

Did my first marathon on Sunday, just missed out on my 4hr target (4.01.09) but really pleased to have completed it. Looking at my run data something really puzzles me...

I'm 45, been running for six years, done lots of triathlons, a few 10Ks and a half - so plenty of race experience. I felt really well prepared - did six runs over half marathon distance, culminating in a 20 miler three weeks ago (with more climbing than the marathon course) averaging 145bpm. In fact all my long runs had an avg HR of around 145, were negative splits and run at 5sec/mile faster than my target marathon pace.

What's weird is on marathon day my HR was up to 155 within the first two miles! And this was the Loch Ness Marathon - the first 10 miles is pretty much all down hill!! (and I was holding back and sticking to my 8.55min/mi target) At a short ascent about mile five, well within my comfort zone, my HR spiked at 172 when on longer, tougher hills in training it's never been over 165.

Whilst I managed to hit my pace target over the first half (five seconds slower than anything in training) it was already feeling tough and I soon knew there was no way this would be a negative split. For the whole of the second half (mostly flat) I was over 160 and in zone 5! I managed to hold the pace until mile 21 (a hill) and then faded.

Conditions were perfect (maybe a degree or two warmer than ideal for the afternoon, but nothing unbearable), I'd had no illness and my fuel and hydration strategy was exactly as practised successfully in training many times.

The only explanation I have is that I had no taper. The day after the 20 miler I was doing a recovery walk and a previous foot injury flared up and I had to hobble the last half mile home. I RICE'd and rested the rest of the week. The following Tuesday my dad was taken into hospital and I spent the next eight days at his bedside (he's now stable). Last weekend, conscious of having to do some training and not wanting the foot to flare up again, I did a three hour bike ride (50 miles, avg HR 136) and a harder 1hr bike interval session.

I know my taper didn't include the two longer runs I'd planned (16/13 miles), but I really wouldn't have thought my fitness would have faded that much (I started base building for this in January). My HR graph looks like I was almost completely untrained.

Anyone got any ideas as to why it went so high and stayed there - the stress of the previous couple of weeks taking its toll? It's really puzzling me - any suggestions welcome!

Comments

  • Race day nerves and the fact that you were well rested. The heart beats faster and more freely when it is well rested. And a race gets the adrenaline flowing.
  • The stress of the previous weeks would have an effect and possibly enough for the result you got.
    I had a stressful 5 months with an ill relative culminating in the funeral 2 days after my A race, but when it came to my A race I ended up as DNF and I am now recovering from chronic fatigue, so take care. 

  • Most likely the stress of the earlier events you mention. Glad to hear you dad is ok.

  • RicFRicF ✭✭✭

    160/170 bpm isn't high. 195/210 bpm is high. 

    Top racers are operating in the 180 bpm plus zone whatever the distance.

    I'm nearly 55 and when racing my HR is balanced at 173 bpm, and that's low compared to the 190 bpm plus of 25 years back.

     If your heart rate isn't high, how else does the oxygen get distributed around your body fast enough and the byproducts of combustion cleared fast enough?

    The reality is, the higher the HR the better the race.

    What slows you down as an older runner is your body's defense mechanisms simply will not allow a high heart rate. That's less oxygen supplied per unit time, faster lactic accumulation, less ability to shift it.

    It makes no sense to want a low HR in a race. 

    🙂

  • tallcmp172 - I had the exact same problem in Berlin on Sunday. Reading your post is identical to what I would have considered writing - even our times are almost identical

    I just put it down pre-race nerves and tried to forget about it. My heart rate was 162 bpm after 2 miles and usually it would be under 150bpm, like yourself. So not ideal.

  • I'm not sure HR is that useful for marathons. I know I suffer from cardiac drift so my hr rises as athe distance increases. So if I ran to it I would slow down.



    I think it's possibly a combination of your poor taper, excitement and maybe some cardiac drift later on.
  • Cougie - I understand the problem with drift later on but we're talking nearly 160bpm (average) after the very first mile. My  test" // 13miles at race pace (early September) and my average heart rate only once went above 160bpm (average) when faced with a mammoth climb. 

    I had done numerous marathon pace runs (8:45 min/miles) in training where after the first mile I was somewhere around 145bpm; and to begin with I was running at 9:00 min/miles as my raceplan. So something is clearly at play but certainly not the end of the world. Just a learning curve going forward.

  • Yes I'm thinking it might have just been excitement at the start and then by the time you'd calmed down it could have been rising due to drift? Impossible to tell really.



    I think it's best just pacing to an even split if you've a decent idea of goal time.



    Kenton did you not just leave all your pace behind in training running sub 9? I do my 20 milers at 9 min pace but race sub 3.15. You could just have been tired?
  • NayanNayan ✭✭✭
    Exactly as vdit says. You should not be surprised if your hr is higher that normal on race day. Especially if you were excited at doing your first marathon.



    By the way, being within a few minutes of your target is a very decent outcome. You should be well pleased. I know I would be
  • No Cougie - test run was 13 miles and then analysing after and hoping HR elevated as expected. I did my very long runs at 10:00-10:15 min/miles

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