A couple of weeks ago I tried "The Minka Kelly Treadmill Workout" that I discovered on pinterest. I have been wanting to give this workout another try, but as of the moment I am sick, :(. If you want a hard and sweaty workout, this is the workout for you.
Minka Kelly's treadmill workout: 1 minute at 5.0, 1 minute at 5.5, 1 minute at 6.0, 1 minute at 6.5, 1 minute at 7.0, 1 minute at 7.5, 1 minute at 8.0, 2 minutes at 4.5 Repeat five times.
When I tried this workout, I was on a time crunch, I accomplished 3 rounds of intervals. I did this on a workday, which gives me a time frame of 30 minutes to workout. I am not going to lie, those 3 intervals were hard. Most of it was in my head, I eally had to push myself to accomplish each interval. My legs felt like jello after the first round. It was totally worth it.