I was wanting to get https://gel-v.com/gelv/v-kit.html and for the v-belt I need to know how big I am. I took a tape measure and measured two inches below my belly button, as per the site, and got 39 ...
I can measure my general fatigue every morning by checking my resting Heart-Rate. It's shown me quite effectively, when I am a bit sick or sleep to little, my resting HR jumps up to 10 beats higher. ...