"resting" HR - is it actually lowest when resting?

neeb
neeb Posts: 4,473
edited September 2015 in Training, fitness and health
Just a curiosity-motivated question really.

I've noticed that the times I measure my HR at its lowest are not usually when I am actually completely resting and have been for some time (say, first thing in the morning before getting out of bed), but rather when I've been inactive, done a very short burst of exercise and am then resting again.

Classic situation: Saturday morning, relaxed, pottering about indoors. Go downstairs to take the rubbish out, run up the three flights of stairs to my flat (just enough to feel the lungs working slightly). Sit down, take pulse maybe two or three minutes afterwards and it's often at its lowest measured rate, lower than it would have been before I ran up the stairs.

My theory is that the HR doesn't reach its lowest rate when completely resting for an extended period as the stroke volume isn't very high. The heart is just ticking over at its lowest level, and the most efficient way to do that is to lower both the pulse and the stroke volume. But a very brief burst of exercise is enough to stretch out the heart muscle a bit, such that when you've fully recovered the stroke volume is higher, so the pulse has to go down a bit lower still to compensate. That's what it feels like anyway.

Comments

  • bompington
    bompington Posts: 7,674
    Absolutely. And don't forget to check out www.cardiologyradar.com for my theories on why you don't need to wear a helmet.
  • neeb
    neeb Posts: 4,473
    Thanks, but I'm sure it's all on http://www.pointlessreplies.com anyway.
  • imposter2.0
    imposter2.0 Posts: 12,028
    RHR will be at its lowest point when you are asleep - the usual advice was to measure it first thing in the morning after waking up. Simply measuring it is usually enough to raise it by a few beats anyway, so I've always dismissed RHR as a pretty meaningless gauge of anything useful.
  • neeb
    neeb Posts: 4,473
    RHR will be at its lowest point when you are asleep - the usual advice was to measure it first thing in the morning after waking up. Simply measuring it is usually enough to raise it by a few beats anyway, so I've always dismissed RHR as a pretty meaningless gauge of anything useful.
    Yes, it's a bit like body weight - any individual measurement on a given day is pretty meaningless but I do notice that resting HRs on average are lower when I'm in decent condition.

    Just curious about the various things that interact to cause it to jump around all over the place and wondered if anyone else had noticed the same thing with lower RHRs a few minutes after a brief, isolated spurt of exertion. Thinking about it more it's maybe something to do with vagal tone.

    Anyway, as I say, just curiosity so feel free to ignore (just as long as you ignore passively unlike the first responder.. :wink: )
  • I find that first thing in the morning my heart rate starts thumping away because I have been startled by the alarm clock going off. Whenever I have measured in the morning it is usually about 70bpm whereas if I measure in the evening whilst lounging about watching TV it is about 52-55bpm. However None of this means anything because I am not very fast on the bike.
  • Mine's 45 bpm upon waking, about 30 when I am asleep
  • diy
    diy Posts: 6,473
    mid morning having skipped breakfast. is normally the lowest for me. it can go up a bit if you are tired. I've no idea what it is when I'm asleep. mine is normally mid 30s. unless it's the fit PT totty at the gym measuring it.