Interval training for runners

I work with a trainer who has a background in distance running, and lately she's had me doing intervals where I'll sprint for 1, 2, or 3 minutes, then spend 1-2 minutes on weight lifting with no break between.  I'm LOVING it, and noticing a big change in my endurance and run times.  Last week, my average mile pace was ~10'/mile.  This week, I'm averaging sub-9'.  Here's the basic schedule:

5 minute warm-up at your avg. pace

1' sprint (1-2mph above your avg pace)
1' leg/lower body weight training
Repeat two more times, with a different exercise for the same region each time.

2' sprint
1-2' core weight training
Repeat two more times, with a different exercise for the same region each time.

3' sprint
3' lower body circuit
3' sprint
3' core circuit

2' sprint
1-2' upper body (chest/arms) weight training
Repeat two more times, with a different exercise for the same region each time.

1' sprint
1' slow jog/walk at 25% incline
Repeat two more times.

5' walking (4mph or less) cooldown

The whole thing takes me about an hour to complete, and right now I'm clocking somewhere from 3-4 miles for the running portion.  When I started, I was getting around 2 1/2 miles.  It's fantastic, but don't do it on two consecutive days or you'll risk injury.

nevarren

All I'm doing is reading your post and already I'm exhausted! I used to do intervals when I was training for the Detroit Marathon but I would do strictly speed intervals at my local high school track along with setups between laps. Starting with 220 Run/220 Jog, 440Run/440 Jog, 1/2 mile Run/1/2 mile Jog. I worked up to 3 sets of each. Then I would alternate weekly with sprint work on a hill (strength workout) by my house. The hill is about 1/4 long. I would sprint uphill from point to point and keep track of my time with a stop watch. After each sprint I would jog back down and start all over. Eventualy worked up to 12 reps.  In between all this during the rest of the week, for muscle growth and healing, I would simply do my "slog miles" (slow jog). Throw some setups, push ups and dumbbells in for good measure.  Some of your workout looks like it might be beneficial to me I might try incorporating some of yours into mine to spice things up and prevent boredom. I must be careful not to overdo it as I am still recovering from knee surgery and the associated weight gain that followed

Definitely give it a try, but yeah, maybe just the core/upper body stuff if you're having knee problems.  I've found it definitely helps me with speed training :)

I know this has probobly been dicussed hundreds of times. But could someone tell me the coralation between my burn rate and calorie intake. CC says I am supposed to eat 1950 Cals a day. To lose weight at a rate of 1-2 Lbs. a week I should have a difference of 500-1000 calories between my intake and my burn rate. What happens if I go out and exercise enough to burn off 1100 extra calories? Should I increase my food consumption by 1100 calories that day to stay with in the 500-1000 calorie difference range? EX. I consumed 1954 Cals today. My normal burn rate is 2560. Today, between my morning jog and my afternoon bike ride I burned an extra 1079 calories. Should I eat the extra 1079 to keep my body from going into starvation mode? As it is now at midnight I will have burned (est)3630 calories so I have burned 1500 calories more than my consuption.    HELP......

Circuit training will definitely help with running faster but stretching is equally important. I have been doing weight training 2 times a week(hi reps low to mid wt) with a lot of stretching recommended by my personal trainer and this has helped to get me back to a running pace I thought I never would do again since I am 50. I may even qualify for Boston. Good luck with your circuit workout I'm sure it will work for you too.