Consistency over time = greatness. However, I can't count how many times there's I've gotten injured or burnt out trying to hit a weekly mileage goal that wasn't entirely necessary. In the shop I get lots of training questions and I guess my best explanation/advice for other runners is to stick to a couple rules that are dynamic with your goals. I guess dynamic training should have some concrete rules, but I think it really has concrete themes. Here's some of my thoughts on the matter:
1) Run fast when you want to run fast
-1b) Run fast with runners that are faster than you, but stick to your planned workout. Listen to your body and cancel speedwork/hillwork when necessary.
2) Run slow all other times (don't do the inbetween 6:30-7:30 pace so much)
-2b) Do easy runs with runners that are slower than you at their conversational pace.
3) Run when you genuinely want to. Take the time to think of reasons as to why you want to run (sunrise, race goals, friends, etc) but, if you don't have any, don't run!
4) Record dynamic last 7 days logs (running weeks don't have to start on sundays) If you run 100 miles from wednesday-tuesday, adjust up or down as you see fit.
5) Vary your terrain often, make it a point to keep your legs guessing.
6) Run however you can to be able to run 6-7 days a week (even if it's 1 mile a day, it's better than 3 days off in a row)
7) Recover with protein, electrolytes, and water! Speedwork and long runs are wasted without protein within 30 minutes from finishing. Salt is going to pump up your blood pressur and help flush things out of your system. Stay mobile and focus on how you recover!
8) RUN BAREFOOT a couple times a week soft sand or grass. Use lightweight thin shoes for training. Thin sandals or sandsocks such as ZEM's are great for walking too. Invest the effort in developing foot strength and stay injury free.
These rules are pretty much what I follow, and they are the guidelines to my training which has been working for me over the past year. However one thing to remember is that things are going to hurt and be hard. There's a certain level of pain for maintaining fitness, a higher level for improvement, and an even higher level for injury. When the body undergoes stress it either grows or get's injured. The best thing I can recommend is pushing your limits, and getting in touch with your body through an over-training injury. Find your limits and understand your body better. Always rest smart afterwards, but go forth from your experiences and keep your training on the edge of the blade to see the maximum returns.
The way I see it, if you're going to run more than a few days a week, you might as well make the most of it and have some fun getting faster and stronger. I'll almost always reply to e-mail questions, and can even help set up training plans. I hope more than anything that this helps readers enjoy running!