I did an indoor brick today; 1.7mi before spin class (1:10 long) then .5 afterwards. All running at a 10min/mile pace, keeping my HR 1/2 in zone 1, 1/2 in zone 2 through the entire workout. And it actually worked for once - my average HR was 154, which is right a the transition between zone 1 and 2. I'm up to 9.7mi for the week (If I'm adding correctly, which is always doubtful )