[HAMR] Heart rate data

[Tim Hall]

Various posts have made reference to Steve and Kurt's heart rate.  Which of the many tracking things to I use to see it?  (at present I use the Hackney website and Ben's Android app).

[matthew]

The heart rate data is embedded in the garmin tracks uploaded to Strava at the end of the day.

I am not sure if you need to be a member or even a premium member of Strava to view it.

[red marley]

It's visualised on Strava (and therefore after the event only), although I think it may only be visible in detail to premium Strava members under the 'analyse' section.

The screen looks something likes this:

[duncan]

It's visualised on Strava (and therefore after the event only), although I think it may only be visible in detail to premium Strava members under the 'analyse' section.

I can see it, and I'm not a premium member.

[NeilH]

The rider needs to be a Strava Premium member for Strava to generate the heart rate zone breakdown report, but anyone can look at the report. And I think the heart rate trace under "analysis" is present regardless of whether the rider is Premium or not.

[JL]

The height profile shown there suggests Milton Keynes has gained about 200m during the day. I guess this is because height is measured by atmospheric pressure?

Is there any other more accurate way of measuring height climbed on a ride?

[Ningishzidda]

Personally, I don’t think Steve or Kurt’s heart rates are important. Above HR in my list of important metrics is their blood glucose level immediately after they complete the day’s riding.

Strava can display the athlete’s HR if the athlete is recording it with a chest band. Strava doesn’t display mg/dL of blood glucose because the riders aren’t being continuously monitored.

I would be happier to see Steve and Kurt’s blood glucose kept stable throughout their riding and resting, than their HR during the riding.

The other metric is their body core temperature, which can be measured continuously ( carefully ) with a thermocouple serving as an a**l thermometer. 

[Wowbagger]

Is there a specialist Brooks saddle for that?

[NeilH]

The height profile shown there suggests Milton Keynes has gained about 200m during the day. I guess this is because height is measured by atmospheric pressure?

Is there any other more accurate way of measuring height climbed on a ride?

Yes - Garmin Edge GPS/Cycle computers like Steve uses have a barometric altimeter, so a low pressure front does show up like a gradual climb through the day.

Despite the scope for weather-related-drift, such things are still reckoned to be the least-worst way to measure climb on a ride. GPS is significantly less accurate at determining altitude than it is at pin-pointing latitude/longitude.

In the absence of altimeter data Strava normally uses elevation data from topographic mapping services, but they tend to have relatively low resolution and can be significantly erroneous - especially if you're near a cliff and get an approximated elevation from the wrong side of the drop! 

[Climberruss]

Is there a specialist Brooks saddle for that?

Brings tears to my eyes just thinking about it 

[andrew_s]

The height profile shown there suggests Milton Keynes has gained about 200m during the day. I guess this is because height is measured by atmospheric pressure?
Is there any other more accurate way of measuring height climbed on a ride?

It's more like 130-140m than 200m (compare distance between 100m and 250m labels with the height at the right).

Normal pressure changes during a day would be more like 40-50m, and you'd expect to have noticeable windiness once it got to 150m during the day. At the extremes the difference between a good high pressure, and the middle of the eye of a strong hurricane would be around 3000 ft/900m.

GPS Barometric altimeters are accurate to around 1m (i.e. difference in height between floor and overhead will show at 2m, subject to rounding errors). The problems are height drift due to pressure changes between calibration and reading, and you can get small dynamic effects due to air moving around the unit (eg when I ride into a headwind, air speed maybe 25 mph, my eTrex reads 3-4m higher if I hold a hand in front than if I don't).

GPS heights are very good if you average them for long enough in the same place, but any one height reading (at once a second) will be in error with a standard deviation of around 10m (about 3x horizontal error). The question then is how long to average the heights over? Too short a period, and the random fluctuations will add into the total climbing, too long and you'll miss out on short-lived local extremes. Garmin don't tell what averaging they do, but GPS climbing is normally significantly higher (like 15%, ish) than either barometric (on a good day) or contour counting.

Garmins that have a barometer will generally calibrate it from averaged GPS height when first turned on, then use & log the barometric height. For most accurate figures, you ought to leave the GPS turned on and stationary for 10-15 minutes before you start to ride, so that real height changes don't confuse the calibration. I don't suppose most people would bother, but you could turn on first, before doing tyre checks, clothing adjustment and other faffing.

[danridesbikes]

Would be interesting to see his Strava fitness and freshness graph and what sort of TSS figures are being accumulated
 

[Mr Larrington]

I don't know how Emily the (Garmin) TwatNav gets her elevation data but the recent evidence suggests she looks it up in the Hackenthorpe Book of Lies.

[macnark]

Yes, I once did a ride which looked for all the world like had gone off for a hot air balloon ride. Got to about 1500 feet above ground! Will see if I can find it.

[Ivo]

Garmins that have a barometer will generally calibrate it from averaged GPS height when first turned on, then use & log the barometric height. For most accurate figures, you ought to leave the GPS turned on and stationary for 10-15 minutes before you start to ride, so that real height changes don't confuse the calibration. I don't suppose most people would bother, but you could turn on first, before doing tyre checks, clothing adjustment and other faffing.

That's indeed what I tend to do. Put the Garmin on the bike and switch it on. Then unlock the bike, mount rackpack & barbag, put the buttles in th bottle cages and check the altitude. When it's off the usual altitude of my bikeshed I wait untill the usual altitude is reached. Then reset the day settings and start out with my ride.

[T42]

Is there a specialist Brooks saddle for that?

Brings tears to my eyes just thinking about it 

The Imperial could easily be adapted.