While the old Garmin is holding up still – even if the screen is getting harder to see – I thought it might be an idea to try a week’s runs by comparing the two. So this morning I went out with the new one on the left wrist and the old one on the right, which felt pretty weird.
As you can see from the two sets of details below, the biggest and quite a large difference is in the calories burnt. The 405cx which takes into account heart rate to calculate calories burnt came up with 317, the 405 which just uses user details had a wapping 468.
The other thing I noticed was on the run itself. The 405 was, at times, showing a much lower minutes-per-mile figure than the 405CX was. At one point the 405 was showing somewhere about 7.30, while the CX was on 8.05. I’m not sure, still need to work this out, but I think it may be that I sped up in the second half of the run and the 405 was showing actual minutes per mile, while the 405CX was showing an average for the whole run.
I’ll give it a go tomorrow by doing a speed session and compare details from that too.
Miles today: 3
Target: 1056
Miles to date: 1,472.28
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Today’s run (405CX)
Today’s run (405)
4 comments
Samuel says:
September 6, 2010 at 19:52 (UTC 1)
Hey mate, I wonder if this is constant on all pre-405 garmin is it taking account of the personal info and not the heart rate ?
I am wondering since i get a old forerunner 305 and trying to figure what is the algorithm to calculate the calories burn for this device.
Cheers,
Sam
worldofjames says:
September 6, 2010 at 20:22 (UTC 1)
I believe it is mate…
Only the ones with CX or XT in the name do heart rate based calorie calculations…
Think this is limited to the 405CX and 310XT at the moment…
Ian says:
September 7, 2010 at 05:44 (UTC 1)
hey, i used to live in Oval so i know your area well. Since moved to australia where the running is awesome!
i have a 405cx. there is a standard route i run which burns roughly 700 calories. Yesterday i ran this without the heart rate monitor and it estimated i had burnt 958 calories. So quite a difference.
so try wearing the 405 and 405cx with the hrm and see what results you get. let me know!
worldofjames says:
September 7, 2010 at 08:52 (UTC 1)
Hey Ian, Welcome to the site! I had a heart rate monitor on which was picked up by both Garmin’s. I’m assuming the disparity is the 405 just takes height, weight, age, distance and speed into account, whereas the 405CX chucks in heart rate too…