30 miles a week before doing speed work?

I never run 30 miles a week. I aim for 32 miles a month and I do an interval run every week. I only run 3 days a week. I've been seeing a lot of studies lately that indicate you don't need that much mileage to be an effective runner. Of course if you enjoy that much mileage, keep at it.

I will say that I did not start doing intervals until I had been running for a few years.

Veronica