Originally Posted by gregf83

I wouldn't worry about going 'hard' until you have some miles in your legs. That might take a few months. The you can start adding intensity. If you try to go hard every time you'll get faster but your 'hard' won't be hard enough. You'll invariably get with a group or a race and find that what you considered hard won't be hard enough. A long winded way of saying that you need to mix up your intensity levels.

If you're only riding for three days I wouldn't waste any on recovery but they don't need to be the same level. I commute 5 days a week about 50-60 km/day. I sometimes have a plan but am usually unstructured and ride by feel. I ride with a powermeter so have a good idea how hard each ride is. I have a few hills which can be sprinted or used for VO2max intervals. Some days I'll sprint on all the overpasses. With a tailwind I sometimes do a 30 min TT on a nice section of highway.

It depends to a large extent on the layout and traffic on your commute. It's not quite long enough to do traditional interval sets like 2x20 or 6x5x1 but you should be able to do some harder efforts. I would consider 'hard' days the ones with VO2max efforts. These are constant effort, all out for 3-6 min with similar rest in between. You could physically do them every day and see good results but they're not much fun. You could try VO2max on tue and Thur and tempo or 'sweet spot' on Wed.

It will take some time to figure out what works. Get a powermeter if you can to track progress.