I am in week 7 of c25k (first time ever) and just completed my second 25 minute jog, not counting the one I attempted to soon after summer and had to quit early due to tummy sickness.

I downloaded a free podcast by Jeff Galloway (itunes) called 30 - 30 intervals. Start by warming up 3 minutes and cool down the same way. In between it is 30 seconds run, 30 seconds walk in non stop rotations. The beats per minutes range between 140 - 165. I like the helpful tips he gives throughout the workout intervals. He said that if this is not your training workout day and you feel short of breath, slow down. He also says find your running comfort zone and stay in it, it makes running enjoyable when this is happening..

I have found by throwing a 30/ 30 run like this in every once in a while on my "off days", it is increasing how "powerful" I feel on my workout jog days. I did give my 30 minute run time much more effort than usual workout day runs.. Jeff Galloway says this is effective for increasing speed.

Good luck to you!

I didn't add in speedwork until I was up to 10 miles a week. It's where you are most likely to get injured. On the other hand, running as fast as you can for the last 30 seconds of the program can be fun and empowering.

Thanks for sharing this! I didn't know speed work was more likely to injure me. I think I'll back off on it then--it's just that it was a fun change from the usual slog. But I have no desire to get hurt!

The odd day isn't going to break your leg, but it does put more strain on your tendons and joints. So if you are prone, say, to plantar fascitis, it could cause a flare up.

Pretty soon the usual slog won't be as much of a slog and your soft tissues will have adapted to the pressures of running. Then you can do intervals to the edge of vomiting too.

I didn't add in speedwork until I was up to 10 miles a week. It's where you are most likely to get injured. On the other hand, running as fast as you can for the last 30 seconds of the program can be fun and empowering.

I am on week 7 day 3 today. For the past few runs I have been incorporating this into my routine. 30 seconds of sprint a couple of times, then 45 seconds a couple of times and now a min. It seems to work for me

I don't think that's going to hurt you.

When I do 400 meter intervals, for instance, I run slowly for 10 minutes. Then I alternate sprinting 400 meters as fast as I can with walking for two minutes about 6 times. Then I run slowly for 5 minutes. I'm totally drained by interval 5 and am barely pushing through the last 5 minutes. It builds your VO2 max and grows fast twitch muscles, the first time I did one my easy running pace dropped by a minute per mile, but needs to be done strategically.