Devin's been encouraging me to run shorter intervals and increasing the speed for some time now. To be honest, originally my joints couldn't handle the impact and faster speed. Lack of muscle around my knees and additional weight made post-sprint work-outs painful (to the point where I thought I'd injure myself), but now that I've been running 6 months, have lost 60 lbs, I'm ready to take it on.

This morning I decided instead of running 4 minute intervals, to make it shorter intervals but increase the speed to 6 miles/hour on the run. Given that I have very short legs, this is putting me at a pretty fast clip. When you go faster, you don't need to do your cardio as long, but I wanted to benchmark it against my other 48 minute interval workouts so this is how I split it up:

12 intervals at 1.5 mins (6.0 mile/hr run and 2.5 mile/hr walk) - heartrate recovery 40-50 beats

6 intervals at 1 min (6.0 mile/hr run and 2.5 mile/hr walk) - heartrate recovery 20-30 beats

The thing I really enjoyed about this workout was that the 48 minutes went by so fast! I might actually try 6.5 tomorrow (at least on the 1 minute sprints).

In the end here were the stats:

Average heartrate: 147 beats
Peak heartate: 186 beats
Total calorie burn: 1000

The best part, talk about sweat... it was CRAZY!

Devin's wife Gina said she has an interval workout that will make my eyeballs sweat... I think I'm going to book an appt with her in the next week to try it out. That sounds kind of fun!