Other (Curling) 1:45:00 
I've been curling for the last couple of winters, and decided to track my heart rate tonight to see how much effort it is to sweep. When I have to sweep really hard I get into zone 4, but obviously not for very long. Between rocks I rarely get back down to a full resting rate, and tend to be in zone 1 as I'm sliding about the ice figuring out angles etc.
This evening was mixed doubles, so I have to hop up and sweep my own rocks (16 per game). On Monday nights I play as skip on a team of 4, and then I'm doing even less sweeping. The closest curling ever comes to feeling like a workout is during practice, when I can get through 60 rocks in an hour. It does seem to help with my hip flexors though, and is way more enjoyable than yoga...