Does the 735XT and SWIM heart rate strap deliver the goods in the pool? The strap records heart rate and transmits it to the watch when above the water line, but does this happen fast enough and flawlessly? Can we put our trust in this technology? Only a pool test would tell.
The crux of the test would be what the 735XT would show in terms of heart rate during rest times between intervals, because that’s when you would want to check your heart rate. I decided on variety to get definite heart rate lows and highs. So it was 250 m easy and 250 m drills times 2, followed by 5 x 100 m at race pace.
After the first 250 m I pressed the lap button for my rest time and lifted my chest strap above the water line. The heart rate detail was already displayed when I looked down at my watch. It was instantaneous and the watch and strap never faltered. After each interval I pressed the lap button with the same result. After one interval the strap was slightly immersed but the info nevertheless jumped onto the screen in a second.
The default heart rate screen is a thing of beauty: interval average and interval maximum heart rate, plus overall heart rate and current heart rate. The rest of the happiness is getting all the detail uploaded onto Garmin Connect after your session for analysis. For those making a career of swimming this would serve them well in the context of coaching, understanding effort levels and even gauging fatigue or overtraining.
Regarding the fit of the SWIM heart rate strap: it has almost no stretch so it can be pulled tight around the chest, especially for male swimmers when swimming bare chested. That, together with the sticky silicone layer prevent the strap from sliding down when swimming. It worked perfectly fine, with no slippage.
The 735XT and the swim heart rate strap will add great value if you take your swimming seriously. Once again the 735XT packs a good punch for its size. Lovely little gadget.