what does the saturday session actually involve? One option is take a longer warm-up. If you normally meet up at 10.00am, or whatever, just get there earlier and go for a run beforehand. That way you'll keep up the mileage - you may be a little tired for the session but that's not necessarily a bad thing.
The hill reps are a good idea but I would be tempted to make them shorter - say 45 seconds, or even 30 seconds, the first time you do them and then increase the time if you feel comfortable.
If your easy runs end up being a few seconds per mile slower that will be fine – at the end of a run like you shouldn’t be knackered, but rather you should feel as if you could have run a little further at the same pace.
But I think you’d be generally fine to do that for three or four weeks and then adjust depending on how you’re feeling and how much progress you think you are making.
Hi ozmo - if you're most recent race is a 22.59 5k then running 3miles at 7.30 per mile is pretty much a flat out effort - definitely not an easy run!
8.30 per mile should be absolutely fine - possibly even a little slower. If you're not sure about the actual pace just imagine having a conversation with someone. During an easy run you should be capable of chatting to someone. That doesn't mean you have to - but you should be able to. Where you are at the moment. I doubt if you would be able to do much talking while running at 7.30 per mile.
The easy/steady runs will help you build up your stamina and strength and will help you cope with races and also the interval training. Your interval sessions (or speed work, or whatever you want to call them) are your opportunities to run faster than race pace - keep your easy runs easy.