Speed, bmp, height, leg length, Garmins and total confusion

I've just done the speed podcast for the first time and was talking to a friend about it and I am very confused.

Laura explained about bpm and running faster. Okay. But how does bpm work? Here's me, at 5'2" with short legs, running at 165bpm. Fine. But surely, if there's someone who's 6'2", with lovely long legs, also running at 165bmp, won't our stride be a different length and therefore won't we run at different speeds? How does the Garmin know? My friend has one, and she uses a footpod with it and said that her stats are 80 - 90 bmp - but is this only recorded every other footfall? She says she runs very slowly, so is this 80 - 90? I can't believe that I was running twice as fast as her, because I know I'm fairly slow too.

Can't you take smaller steps and therefore not be running any faster, moving from 155bpm to 165 bpm? Do you expend more effort this way anyway? How do you actually track your speed on a real run - especially if you don't own a Garmin (other equivalent products are available)?

Ack - my brain hurts! Can anyone help?

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  • Garmins also have a GPS facility on them, which is how you will know how far you will run. You're right about cadence and stride length - my other half and I have roughly the same bpm, but he has a longer stride, and is therefore faster. If you have an android or iphone, you can download apps to work like a Garmin. Try endomondo or something like that (it's free), and there are ones you can pay for.

  • That's helpful, tub - thank you. I was sort of thinking that bpm is fine but can't - surely - be the same for everyone. Or the bpm is but the distance must be different. I'll see what I can download - thanks for the advice.

  • I'd love to hear the answer too! When I did some pace counting, just out of curiosity, I was doing 160 steps (which seems to count as 80 strides? - so like your friend). I'm slow too, and have middle-sized legs - there, that helps lots, doesn't it?! :P

    I guess the idea is to take same length steps, but more of them, to go faster?

    However... Now I had a vague memory from reading chi running, that he recommends using the same cadence (steps per min) for all speeds - so just looked it up. And it wasn't my imagination: "That's right! Your cadence should stay the same whether you're running fast or slow, up or downhill, or trying to catch a bus. Keep it the same, no matter what!"

    So - two totally different ways of speeding up! That helps even more, doesn't it? :P

    In the interests of people who like to look at things from all angles here's a link about it - though I've not tried it, as don't have a handy metronome (or smart phone): chirunning.com/blog/entry/r...

    Maybe I'll just stick to make it up as I go along. Perhaps our bodies can work it out for themselves. Fun to play with ideas though.

  • See, it's totally confusing! I'll have a look at the link you've kindly provided tomorrow, 'cos my brain hurts now :P

    But I'm still pondering about how I'm going to learn to go faster. I see that intervals will make me fitter, recover faster etc. but actually covering more distance in a shorter time? Not sure yet.

  • Maybe we should just stick to oldgirl's lamppost routine, rather than complicated counting. I know my 'normal' pace is gradually getting faster, as I do more little bits of speedier running. Let's just fartlek! :)

  • The faster bits felt okay, and I did Stepping Stone today where you run at 160 bpm for longer, and it felt okay, if knackering :D

  • Glad it's working then! :)

  • OK, A garmin running watch is a gps device and tracks runs/walk from the satellites. It's constant pinpointing location and measuring time, so can calculate your moving pace or speed. I don't know about footpod, but I presume it measures each double step, ie measures each time the left or right foot touches the ground. Why is this important? Well, I think it is good to be able to keep a steady footfall.

    > Can't you take smaller steps and therefore not be running any faster, moving from

    > 155bpm to 165 bpm?

    Certainly and this happens to me, if the increase in bpm coincides with a incline. All the routes around my house involve some degree of ascent at some point. When I'm running with a podcast with a fixed bpm, I try to keep to the beat when going uphill. But I will be slowing down on the hills as I take shorter strides.

    If you wish to track your run without a running watch or smart phone app, you'll need to measure distance on a map (you can use a mapping website, such as openstreetmap) and time yourself, then do the sums. However this won't show you where you went faster or slower.

  • Ah, thanks, swanscot. I was sort of aware that when running uphill, particularly sharper inclines, my steps shorten and I slow down, although I do try not to. The overall pace calculation is easily worked out on Cool Running, for those like me who can't do the maths :D but you're right, it doesn't show faster or slower. It looks like I'm going to have to bite the bullet and either upgrade my mobile or buy a Garmin or equivalent, because I'm getting fascinated by the stats now. More money spent on running :D

  • Here's a link you may find useful. It links bpm, stride and running pace. When I do the podcasts I try to run at the pace in the table on this site rather than count BPM. I'm hopeless at keeping to a beat so this works better for me. Also as I've got short legs too, so I cut myself a bit of slack on the basis my stride length will be shorter than that of the runners in their study. If I'm going up inclines then I try to keep to the same perceived effort as when I was on the flat - so in other words I shorten my stride and probably have a similar bpm but I'm going slower because its uphill.

    You do need a Garmin or similar to do this tho'.

    run2r.com/Technical+linking...

  • Interesting table - but way, way out for me! (It does say for seasoned runners, and the teeny weeny print at the bottom says it may vary for individuals according to technique, stride length and fitness - so useful if you're average, and a 'seasoned runner' - but I suspect many of us are not!)

    On the run where I counted, I did about 160 bpm, but my pace was 9min /km (not 7min/km as the table suggests - that's much much faster than me!)

    So I can see what you mean now, jennie, by running at the pace rather than the bpm, for the speed podcast, and how you used the table to convert bpm to intended pace (though presumably that sort of defeats the object of the 1234 business - but you still get guided through changing pace by Laura).

    I think I now understand what the speed podcast is aiming at - but not so sure it would work too well for me, without changing how I run. I'm glad I understand it now though!

    Oh, and the uphill thing - if it's a short bit, putting in extra effort and keeping at the same pace will work, but for longer hills, as jennie says, aiming for same perceived effort - shorter strides, so slower pace will likely work better (but similar heart-rate, I imagine, if it's similar effort - another meaning of bpm, which confused me for a moment). I think I prefer the chi way of keeping the same rhythm, just varying the length.

    I suspect that may not make too much sense, but too much wine to rewrite it now. Ho hum. Well I think I understand it better now anyway, so thank you. :)

  • Its a bit aspirational for me too! I cant do the fastest pace on speed but what I found helpful was that Laura did expect us to slow right down after each fast interval. Until Id seen this table I was running too fast in the slow bits which meant I struggled even more on the fast interval

    I've been reading a lot about perceived effort and I'm now trying that out when I do the podcasts. Just like oldgirl's lampost routine, I think it's easier than monitoring pace or counting bpm.

    Envy you the wine - only two more days to go before I'll have a glass or two, thats after seven weeks of deprivation. I can't wait!

  • Erm... I think that was helpful, jennie!!! I sat and looked it, then wandered off to do something else for a bit in the hope that it would make sense when i looked at it again :D Actually, it does make sense, I think the problem is in sticking to it rather than understanding it now. I'll keep practising.

    Enjoy your wine today!

  • I'd seen that table previously - or something similar- and it sort of works for me (a wee wifie @ 5'4" and short legs) up to a point. I currently do my tempo runs at about 6:00 mins/km and and I've found the podcasts at 163 bpm are good.

    Last week I tried a podcast with a beat of 165 and my pace was between 5:30 and 6:00 mins/km depending on the gradient. I've found as the bpm gets faster, I don't push myself so much to stick to the beat (except for sprint intervals), so I'm not seeing the improvement in pace I should.

  • I'm impressed, swanscot - I'm 5'2" and found the bmp of 160 fast, so your 163 and 165 look amazing to me!

    I'll keep trying, and I'm sure I'll get faster at some point.

  • I've studied the table some more and looking at the column for stride length, I think the reason I can't seem to get any faster (ie cover more distance despite running at 163 and 165 bpm) is because I take such small steps even when going faster. I've not measured, but I bet I'm not striding 1.2m when running at 166bpm. According to the table, if I did 1.2m strides when running at 163bpm, I'd be flying along at 5mins/km.

    I think the only time I really stride out is when running the speed intervals (170bpm) on the Audiofuel podcast, and I only manage to keep going at that rate with long strides for about 5 intervals - intervals ranging in length from 30secs to 60 secs.

  • Oops, mistake. I meant " According to the table, if I did 1.2m strides when running at 165 bpm, I'd be flying along at 5mins/km."

  • Aaaagh, too much fermented grape juice imbibed for me to make sense of this thread! Will revisit tomorrow ;)

  • So that's how the guy on the next treadmill was matching me step for step but running at 7 mph to my 5.5 - yeah I peeked.

  • It's still complicated and confusing - for me at least :)

  • Speed = Distance / Time.

    If you have a shorter stride, you will cover less distance in the time that you're running for. If you have longer legs and run for the same length of time, your distance will be greater so your speed will be higher.

    Garmins and other similar devices will use GPS to track the distance you've run by means of knowing where you are at a given point in time and a clock to track time elapsed during your run.

    The whole thing about BPM is that if you run at one BPM constantly then run at a higher BPM you're increasing the number of strides you take in the time that you run and therefore you increase your speed. That would assume that your strides are constant throughout your run which may be difficult on hills and such.

    If two people run at the same BPM for the same length of time and have different length strides their speed will be different because they're covering more distance.

    So yes, you're correct in that even if you change the BPM you run at you could change your stride and maintain the same speed. I think Laura is assuming that you won't change your stride too much when you run.

    There's lots of free phone apps out there that let you track this stuff as most phones these days have GPS functionality inside them. I think someone mentioned Endomondo above, that one seems to be quite popular.

  • Thanks, that was very helpful. I can't afford a Garmin but as you say there are plenty of free apps out there and I think it's time to start getting a bit more technical about my stats etc. I never was very good at maths, and the only speed/distance/time thing I can remember is 60 miles in an hour at 60mph :)

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