Interval training is performed and designed to build a person's VO2max.  These workouts stress your aerobic system for a short period followed by a short recovery.  Ideally, to recieve the maximum benefit of these sessions, your interval should last 4-5 minutes each. For those of you that have never done an interval workout or if you do not have enough of an aerobic base I would recommend that you start with approximately 1 minute long intervals with an equal amount of rest in between.Generally, you want to do your interval session at a local track. This helps you stay on pace and allows you to be consistent with each repetition. 

FOCUS

Your interval session should have two primary focus points. The first is to train at a pace just below your anaerobic threshold for the marathon or half marathon. For most runners, your interval pace will be slightly faster than your goal race pace. In the years I've spent coaching I have typically noticed that a runner with a 4:00 hour marathon goal would normally be able to run his or her intervals at 2 minutes faster than race pace.

For example, let's say Ed can run a 4:00 marathon. This means that Ed can average a 9:10/mile race pace. A typical track workout for Ed would be as follows:

• Warmup for 1-2 miles at an easy pace slower than a 9:10/mile,
• followed by 6x800 meters (2 laps) on the track between 3:45-3:55 for each set.
• After each 800, Ed does a recovery jog no longer than 2:00 minutes before starting the next set.
• Finish with a 1-2 mile recovery run at eacsh pace.

The second focus of your interval session should be to stay on pace. Consistency, consistency, consistency, is your goal. You will not receive the full benefit of your interval session if at the end of your workout your interval times looked like the following:

Interval session #1

1st 800: 3:30

2nd 800: 3:35

3rd 800: 3:40

4th 800: 4:00

Total distance covered: 2 Miles

Total time of intervel (not including rest time): 14:45

Average mile pace: 7:22

 In this example, it is evident the runner started off great and gradually ran slower and slower. Now, assuming this is the first time this runner has done this particular workout and weeding out any other factors such as sickness, dehydration, etc, it may be safe to say that the runner started too fast for his or her own ability. By doing so, the body just learned to start off strong and finish slow. On race day your body does what it trained for. And if you train your body to start strong and finish slow then non-suprisingly enough your race will follow the same pattern. How do you learn from this particular workout? Let's take a look at the data. The total distance of the workout was two miles. If we add up the total time of these 4 intervals it would add up to a 14:45 two mile which is an average of 7:22/mile. Knowing this, a runner can now create and complete a more efficient workout where he/she can reach a full benefit from. Here's how the runner's second interval session looks like:

Interval session #2

1st 800: 3:40

2nd 800: 3:40

3rd 800: 3:40

4th 800: 3:40

Total distance covered: 2 miles

Total time of interval (not including rest time): 14:45

Average mile pace: 7:22

 Notice the average pace is still a 7:22/mile. What's the difference? The runner was able to perform more efficiently and trained his/her body to pace itself. All the runner had to do was slow down 10 seconds for the first 800 and maintain that pace.

FINDING YOUR IDEAL TRAINING PACES

How do you know how fast your interval workouts should be? There are several ways and websites one can go to that will help you figure that out. Here's what I've created to help you find you interval training paces. Now, before you use start implementing these paces to your intervel sessions, you should figure out where you stand in terms of your own fitness level. (Visit http://werunsanantonio.com/program-description and read about how to find what goal you should try to shoot for.)

Once you have figured out what goal to shoot for either by a race or time trial then you can use the following charts to help figure out what your ideal interval training paces are. The chart gives you the following info:

• Your goal finish time and race pace
• Interval pace times for track workouts starting at 200's up to mile repeats
• Your recovery time between each interval

I have also included a link to a page that gives you sample track workouts to choose from. Run Happy

MARATHON INTERVAL PACES

HALF MARATHON INTERVAL PACES

SAMPLE INTERVAL AND TEMPO WORKOUTS