I have swum with my new ionic twice now, with Swim auto-detect enabled. Version 27.32.10.20. The first time was when I discovered that the Fitbit what was monitoring my heart rate so accurately on land was giving super-slow HR when I swam, like the upper 70s when my HR was really 110-130. And then it computed my calories based on that low heart rate, thus super-low, etc.
That’s when I started going through all these online discussions about it, and found the “fine print” warning about HR measurement not operational. Had that warning been more prominent, I would not have bought one in the first place.
But... I also saw a couple of suggestions to tighten the strap when HR is not recording right. So before sending my Ionic back for a refund, today I tightened my strap about 3 notches tighter than yesterday, so the band was Very Snug, but not cutting off circulation, and... The HR recording was spot on accurate for over an hour! Workout HR history and calories burned were all reasonable numbers! So if you don’t hear from me again, give it a try. (tightening the strap as much as you can without cutting off circulation). Oh yeah, loosen the strap after your swim workout, of course.
Finally, the workout reported distance was in meters, but was accurate to 1-3% in distance swum (which I keep track of anyway), I.e. using your arms. Kicking with arms motionless (board or no board, fins or no fins) Is apparently not picked up for distance, which is a documented shortcoming, and hopefully Fitbit fixes some day. But if you are doing an organized workout, you almost certainly have the exact distance on hand, so just go edit your workout and put in the correct distance in. If you are swimming open water, then swim, keeping your arms moving.
One other thought on establishing good contact between wrist and tracker: if you have really hairy arms (not my problem), consider shaving the area under your watch sensors.
Happy Swimming!
