Splitting 10 mile run into two 5 mile runs

[Royce]

Some times I dont have time to complete a ten mile run, so what if I run 5 miles in am and then 5 miles in pm.
Also, do I increase my tempo when running 5 miles at a time or should I stay at the 1 min. or 1 1/2 min. slower than MP.
This am I ran 5 miles, and ended up running it only 20 sec. slower than MP. Im not sure that was good even though I felt fine after, maybe tonight I'll runn the 5 slower or should I keep the pace up.

[Jeff Linger]

If you're going to do 1 of the 2 runs up tempo, back off on the 2nd run. BTW, studies show that runners who encorporate some 2-a-days into their workout regime tend to improve their overall threshold pace (AT/LT pace) more significantly than runners who do not encorporate this.