I'm a 800/1500 guy running 50-60 miles a week. In the past I was religious about getting in my Sunday long run of 20% of my weekly mileage (10-12 miles at my level).
But the past few months I haven't been doing that. I've done maybe 3-4 runs the last 6 months in the double digits. The rest of my mileage is coming from workouts, double days, and runs of moderate distance (5-9 miles) at a strong aerobic pace.
And you know what? Cutting out the long runs hasn't seemed to make any difference. I recently ran indoor pr's for the mile and 3k even though it was only December.
At what race distance or performance level does one need to start doing regular long runs?