I just took a 'sweat test' from a hydration expert — here's what I learned

A photo of a sweat test being done, with two electrodes on a forearm.

I've spent the last couple of days on a fitness retreat with budget behemoth Amazfit, whose Whoop-dupe Helio Strap I love. But I've been at this fitness retreat for a different reason — testing the brand-new Active 3 Premium (full review incoming!).

After completing 5ks, challenging hikes, relaxing yoga sessions and strength training, I've been learning so much about my body and my fitness level.