I'm buying an Apple Watch but I value getting as much battery life as possible. I'm thinking of turning off the heart rate sensor. I'm just wondering what I lose by doing that. In terms of health, I plan to use the watch for a bit of swimming and yoga. I also take a walk everyday - maybe for about 45 min. While it would be nice to know how many laps I swam, how far I walked or how much time I spent doing yoga, I'm not really that interested in things such as calories (I'm not even sure what calories mean to be honest). Besides Calories, is there anything else I lose by turning off the heart sensor? Does it effect the watches ability to measure how many laps I take of how far I walk?