After a 3.5ish hour session, I glanced at my Apple watch and was shocked to see that I had burned almost 1K active calories! The reason? My heartbeat, which is usually in the low 60s resting rate, was around 110-115 for almost the entire window. I try to polish for an entire song before taking a quick break, but other than that, I put no thought into it. Felt like others might appreciate that there is a health benefit to this hobby.