@Ian - When junior arrives you'll probably have a different view! I totally agree with Rob, finding time for 90+ minute runs is really tricky to balance. Currently it's mostly shorter 45/60 min session of hi intensity.

back to the OP. I think you'd benefit from shorter faster session. pretty much what everyone else has said! As one of the old guard at my club says "Train fast. Race fast" and he was pretty handy in his pomp!