Training day 50 - 10K tempo run

The weather out there was still horrific yesterday so it was the tread mill again. Thus makes a tempo run a lot easier or what i understand is a tempo run. From what i have read it is maintaining a pace a percentage faster than your race pace over a distance so yesterday i did 6 miles @ 8 min 20 sec per mile which considering where i am at is 25 secs per mile faster than the 8.45 i want ti be doing for my marathon target time. I even cranked up the pace over the last mile. No reaction from my calf and felt pretty good after the effort. Seemed to recover quite quickly. Ok it was the treadmill but needs must when the weather is as bad as it is just now. Hopefully it will improve tomorrow because by my schedule it should be a 13 miler tomorrow. I have given myself a rest today simply because my calf feels a little tight and the weather is crap today again. Fingers crossed for tomorrow