Circa 20 hours per month for me spread across running (Two Fell sessions as week and some road) and a fixed gear commute to work and back once a week.

In terms of training with others. I train once a week with a friend and it's my fav session. I set of with a head start around the route. He (being the faster runner) then sets off and tries to catch me by the end. My job is to hold him off. The start changes dependant on previous weeks result. Ie. If i "Win" by 30 seconds then next week the start drops that amount.

Really good session and we have both improved as a result of it