I recently purchased a Garmin Fenix 5 training watch, and wore it at Sunday's Northern Wave-sailing Event. The figures were quite astounding, but now I know why I feel like I have been run over by a bus after a few hours on the water.

GENERALLY SPEAKING -
My maximum (achievable) heart rate - 190 bpm
My maximum 'calculated' heart rate - 166 bpm (220 - age - yes, very funny...)
Resting pulse - 38 bpm

I cycle quite a bit and have a pretty good handle on how hard I am working at any moment, as well as over time, and I always wear a heart rate monitor on the bike. I have tried a number of times to ride with an AVERAGE heart rate of 160 +. It is almost impossible, and I have only done it once. The figures that the Fenix collected at the Sunday session were as follows:

NORTHERN WAVE-SAILING EVENT -
Duration - 2 hours (approx.)
Maximum heart rate - 181
Average heart rate - 166
I consumed calories at a rate of just under 1200 / hour.

My heart rate dropped out of 'Zone 1' for just over 1 minute for the duration of the sail.

If I was riding my bike to these numbers, I would have hit the wall, vomited, collapsed, passed out, and probably died on the side of the road.

Now I know why we had to sign that waiver to acknowledge that we were partaking in a dangerous sport. It isn't the physical bodily damage of smashing yourself to pieces on your gear, it's the risk of complete physical breakdown.

I am left wondering if sailboarding is actually good for you, or not...