4 miles HIIT (see below)
30 minutes yoga
You guys already know how much I love interval training. I've been incorporating 2 HIIT workouts a week into my schedule, and those are the days I most look forward to exercising. I've found that Pinterest is a great tool for finding treadmill interval workouts. I typically find one I like and alter it to my level, like the workout I did yesterday (adapted from this workout).
Done as written below, this workout covers just over 4 miles in 40 minutes, and because your mind is engaged the entire time while alternating speed and hill intervals, the workout flies by. Everyone who has ever gotten on a treadmill knows how mundane it can be, and even if you're feeling great physically, it's always a mental struggle to run in place for miles at a time. I've found that interval training combats that mental struggle because you are focused on the constantly changing speeds/inclines rather than the completion time or total miles. HIIT workouts tend to be lower on the mileage end than a typical endurance run, but your body will work even harder to keep up with the interval changes, burning fat for hours after the workout.
I will warn you...though the workout does not exceed 7.0 mph (which is roughly a 8:30 min/mile), you will feel the burn. That 10% incline that peaks his head out at the 15-minute mark is KILLER. I found it to be the hardest 2 minutes of the workout and had to fight every urge to not decrease the speed to a walk. It's guaranteed to get your heart pumping and your quads burning. Challenge yourself!