A few weeks ago I mentioned I’d be racing an olympic distance triathlon with a stack of wearables strapped to me. Well, I did it, and here are the (raw) results.

TL;DR: Raced a tri with WHOOP, Polar360, Helio strap, Garmin Instinct 3, and Oura Ring 4. Polar was the most reliable, WHOOP decent but spiky in swim, Helio finicky about placement, Garmin surprisingly messy, Oura useless for sport.

For anyone not familiar, Olympic distance triathlon is:

1. 1.5km swim
2. 40km bike
3. 10km run

On the right arm I had the (from top) WHOOP MG, Polar360, and Helio strap stacked up. On the left, the Garmin Instinct 3 and Oura Ring 4. I looked ridiculous (but not more than everyday since I wear them all constantly), but I was curious to see how they’d compare across swim, bike, and run in real race conditions.

Hybrid athlete xD

Here’s how it went:

• Swim: I got both legs cramped at 1km mark. Thoughts of DNF were running through my head, but I really wanted to see the comparison (:P), so I prevailed and swam the last 500m with my arms only, dragging my uselessly cramped legs behind me.
  • WHOOP thought I was hitting 200 bpm most of the time (I wasn’t).
  • Polar, Helio, Garmin seem all decent, in similar range, although knowing my HR from many other swims, I'd say that Polar was the most accurate.
  • Oura basically zoned out for the full race.
• Bike: When I finally got my legs moving again, the bike leg went smoothly. Hit a steady 34km/h avg pace. I could've pushed more, as my HR was between 150-160, but I was afraid of losing my legs again.
  • Helio struggled at first, underreporting HR badly (I noticed on my bike computer that it was connected to), until I moved it higher up my arm mid-ride. After that it snapped back in line.
  • Polar and WHOOP held strong.
  • Garmin was all over the place with noisy spikes. .
• Run: This was actually the easiest leg for all wearables, and myself. By the end of the run the different devices were surprisingly aligned, except Oura that was again useless.

Overall impressions:

• Polar360 was the most reliable of the bunch. I was definitely not expecting that!
• WHOOP is decent but not flawless, especially in water. It had the best arm placement of all the wearables, so there should be no excuses (I know some people will find many).
• Amazfit Helio started with a disadvantage of being the lowest on the wrist, when moved up, was decent. In my opinion better than WHOOP, worse than Polar360.
• Garmin Instinct 3 really surprised me with how messy the HR data was. I am very negatively surprised with these results.