Interval Training

Today Karen and I joined our Galloway Group for a one mile miracle mile and then a supposedly 6 miles run. When we measured the 6 mile run it was really a 5 mile run. So we went from speedy 10-11 min miles to 12-13 miles in seconds. However, it was a good run as we did intervals (ran fast for 2 mins, HR 160, and then walked 1 minute). I think this is what I have to do to get faster and get used to the heavy breathing that comes with running faster.