I was lucky enough to be picked as an Epson Runner, which means that over the past month or so I’ve been testing out the Epson Runsense SF-810 against my trusty Garmin Forerunner 910XT.
Phew, why do sports watches have such flipping long names!?
One of the selling points of the Epson watch is the built-in HRM, which uses an integrated optical sensor to monitor your HR from your wrist. Epson claim that this is just as accurate as a chest strap. Needless to say, I was a wee bit dubious – as were the friends I mentioned it to.
The question is, can a built-in sensor really give you the same accuracy as a chest strap?
Or on the flip-side, is a chest strap really the only way to get an accurate reading?
In the name of science, I risked looking like a complete numpty with my 2 watches and tested the Epson alongside my Garmin on this week’s long run:
By about 40 minutes into my 10 miler (i.e., the top of the first nasty hill!), the watches were around 2-3 bpm apart. There was a bit of a glitch at the beginning as the Epson decided to split the first mile into 3 laps of 0.08, 0.00 and 0.91 (no idea how that happened!)
But besides the squiffy first mile, the readings seemed fairly close between the 2 watches:
As my handy little diagram above shows (lol…) the overall average for the Garmin measured as 159bpm, whilst the Epson showed 168bpm.
In a slightly more readable format, the HR splits were:
M2: Garmin 139, Epson 162
M3: Garmin 170, Epson 167
M4: Garmin 168, Epson 170
M5: Garmin 167, Epson 171
M6: Garmin 167, Epson 171
M7: Garmin 169, Epson 165
M8: Garmin 169, Epson 171
M9: Garmin 168, Epson 170
M10: Garmin 173, Epson 168
Whilst I found this experiment quite interesting, I’m not an expert when it comes to training by heart rate. According to various places – including Runners World – my LSRs should be in the 60-70% zone (117-136) and hills should peak at 85% (165), which means that I was way out of the target heart rate zone if either of those watches were correct.
How can I have run 10 miles in a zone that Runners World reserves for 5-10k race efforts!?
Do you use a heart rate monitor, or train to heart rate zones? Any tips?
Do I reeeally have to slow down as much as I think I do!?
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Disclaimer: Whilst this isn’t a sponsored post, in exchange for leaving 5 video reviews I am allowed to keep the Runsense, which I tested without charge.