<human>: Summarize the given text in a few sentences.

Right now I'm running to maintain a base, doing 5 runs/wk for 20-30mpw, and helping a couple of friends train for their upcoming half.  They aren't quite on the same schedule, so he was scheduled to run a 7 mile long run this weekend while she is scheduled to run 9.  My longest run so far this year has been 6 miles last weekend with him, but my regular run is 4-5 miles.

He's got the flu and won't be running this weekend, she's planning to go 9 tomorrow (if the ice melts a bit) and has invited me along.  I'd like to do the distance, but I don't know if doing nearly double my regular run, and 3 miles over my long run is advisable.

My primary concern right now is building base and preventing injury/overtraining.  I burned myself out last year by increasing long run distance too quickly and don't want to repeat the mistake, but I also feel like I've got a better base and more experience now.
<bot>: Running 20-30mpw, longest run this year 6mi, reasonable to do 9mi long run tomorrow on a day of rest?