Mid-term Goal

I've been running hard this summer and worked to running 12K once a week. Hope to increase this by 2K every other week. My 3 month rehabilitation period has really taken its toll on my physical condition which means I had to start from about 5K as a long run and about 3K for regular runs. Recently I started to incorporate interval training, which means I try to run faster than my race speed in three sets. First set is for about ten minutes and then I take a walking break for about 2 minutes. Second set I run fast for 8 minutes and take a ninety second walking break. The third set I run fast for 6 minutes and cool down with a ten minute jog. The first time I tried this it was easy so I hope to increase the fast runs by 1 minute per set (=3 minutes) every other week.
Now, for my mid-term goal, I've decided to run a 10K race in November. This will give me an indication of the tempo I could run at my next marathon (without injuring myself again). The thing is though, that I'll run with some colleagues and friends who might slow me down as I know that I'm the fastest of the bunch. Maybe I'll just run alone and meet them at the finish line.