"The definition of an interval is the space between two events or a pause, or break in activity; according to the Google definition. Most of us think of intervals as the super hard effort to get faster, whether it be in the pool, on the bike or during a run."

As a coach, having taught many beginners how to swim, bike and run, we base almost all training sessions using intervals. For a beginner swimmer, it might be a set of 25 yard drills, with a certain amount of rest. For the bike we may start someone on the trainer, and give them 5 to 15 minutes of pedaling and then a rest period before they start up again. And with running, we usually use a walk-run method with someone new to running. So, from day 1 of training we use interval training.

As we progress and increase the distance in running, we add more intervals into the training. Sometimes we’ll increase the distance of the interval, the time, the grade (uphill!) or all of the above. You can start intervals from your first day of running, but remember to keep the effort easy and manageable. You could start with 1 minute of walking and 15 seconds of running or if you are ready, something even a little longer. It’s all up to your personal starting point.

Intervals help a runner manage the intensity and learn to push at a pace that’s out of their comfort zone. This will allow them to run at an easier pace more comfortably.

There are many type of intervals sessions! Here are a few examples:
1. Strides
2. LT (Lactate Threshold)
3. VO2
4. Hill Repeats
5. A mix of all of the above

Examples:
Any running that is done around Lactate Threshold (LT) effort should be no more than 15-20% of weekly run for a runner. LT is determined by the heart rate / effort and or pace that you can maintain for one hour. If you’re just beginning you may be a long way from that, and that’s ok. For example, even with an experienced runner who is running 30 miles per week, then less than 6 miles per week would be appropriate for intervals. The problem many athletes get into is running a 4 or 5 mile interval workout, very hard, but the total weekly volume is only 12-15 miles per week. That’s a recipe for injury and hopefully this article will help you avoid that!

Strides:
Strides are done to help cadence and form. Usually a typical stride workout would be a 10-15 minute warm up, then a 20 to 30 second effort at current 5k pace. You don’t need to run faster than that if you are just starting out. I recommend about 4 repetitions starting out, so the correct terminology would be “Easy run with 4x 20-30″ strides”.

Lactate Threshold:
An LT workout might be a 1-2 mile warm up, then some run drills, then some strides (see above) and then a set of efforts around your 10k or your best 1 hour best effort run. A common example would be 3×5 minutes at 10k pace with an easy 2-3 minute jog in between. You may start out with 1-2 repetitions, and build up for there. Always cool down after the workout is over. The terminology for this workout would read “3×5′ at LT, with 2-3′ easy walk/jog in between hard efforts”.

VO2:
The same warm up as above would work, the main set could be 30 seconds very fast, with 30 seconds recovery, repeated as many times as you can. You may start out at 5 repetitions and build up to 30 reps over several weeks. The terminology for this workout would read “5×30″ with 30″ recovery at faster than 5k pace”.

Hill Repeats:
My favorite! Hill repeats are speed sessions disguised as super hard work. After a proper warm up, like above, you can run up a fairly steep hill (4-7%), for 2-3 minutes with the same effort you’d race a 10k. Start out with 4 reps and build up to 10 reps. The terminology for this workout would read “4-5×2′ at 10k effort, with an easy walk/jog to the base of the hill”.

Cool down is always essential!

A Mixed Bag Workout:
2 mile run warm up, then 4×50 meters of run drills (Butt kicks, high knees, fast feet, etc), then 4×100 meter Strides. An example of the main set would be 8×30 seconds on / 30 seconds off, then move to a close by hill for 4×2’ hill repeats; and then you could run 1 mile at threshold to finish off the workout. This workout would mix in everything from above and keep your workouts fresh. Don’t try this workout unless you are comfortable with all the other sets. In addition, you can do this entire workout on the treadmill.

A final caution: Don’t rush into intervals – take your time, build your mileage slowly and wisely. When you are ready, start with some strides and then move into some hill repeats. The last two types of intervals you should do are LT and VO2 max. In reality those types of workouts are over done by a lot of athletes, especially beginners. The real focus should be on running consistently, improving your run form and cadence, both of which can be done by doing strides. The LT and VO2 work is really the last 2-3% in fitness gains before a big race.

Good luck!