Weekly Workout: Everything you need to know about running intervals

Once you’ve been running for awhile, have established a good aerobic base and are feeling healthy and injury-free, varying the intensity of your training becomes the next logical step. In addition to routine runs including long runs, workouts are an important piece of the training puzzle if improvement is one of your goals.

RELATED: The what, when, why and how of any workout

Running intervals is probably the most popular type of workout a runner might do. But what exactly is an interval and how are they run? We break down everything you need to know about this important type of workout.

What?

For simplicity, an interval is any shorter segment of running that is (usually*) a specific distance or time and run at a specific pace or speed. Intervals are run within a longer run that often includes a warm-up (easy running before starting the workout), rest/recovery breaks (easy running or walking between hard intervals) and a cool-down (more easy running after the hard section of the workout). Intervals can be time-based–lasting from 30 seconds (or less) to several minutes (up to ten or more)–or of a certain distance–common examples include 200m, 400m, 800m, 1K, 1 mile (1.6K) among others. The structure of an interval workout usually looks something like this:

Warm-up – X number of intervals (of certain time or distance) with Y amount of rest/recovery between – Cool-down

Examples:

3K warm-up – 10 x 400m at 5K pace with 200m rest between – 3K cool-down

15-minute warm-up – 5 x 5 minutes at 10K pace with 2 minutes rest between – 10-minuteute cool-down

Warm-up – 8 x 1K at Half Marathon pace with 400m rest between – cool-down

* A fartlek is a unique type of interval workout where the number, length and speed of intervals are determined spontaneously and randomly.

Why?

Intervals are designed to practice running at faster speeds/paces than what is considered easy or comfortable. Running at faster paces develops the energy systems that allow a runner to improve their fitness, become more efficient and also teach you how it feels to run at a given pace. This helps become more familiar and comfortable at that pace which is useful when trying to maintain it during a longer run or race.

When?

Dedicated interval workouts should be done just once or twice a week and should be proceeded and followed by a few days of easy/recovery running or days off. Aim to dedicate at least one day per week for a hard interval workout and when that starts to feel routine, consider adding a second day of shorter or easier intervals (or a different type of workout such as a tempo run). Remember most of the running you do should be easy and done at a comfortable pace. You should also make time for one longer run per week to develop endurance.

Where?

Intervals can be run almost anywhere including on your favourite running routes. Some interval workouts–such as 200m, 400m, 800m or mile repeats–may be well suited to running on a standard 400m track. Others, especially longer intervals are best done out on the roads or trails. There is also added value in running on the roads because this more closely mimics most race-day conditions including varying terrain, elevation and even weather. Better still, you can practice running on the roads or trails that specifically mimic what you’ll see on race day such as over rolling hills or on a specific type of surface.

Who? 

All runners of all abilities should consider doing interval workouts as part of their training. Shorter intervals are particularly important for success at races such as the 5K and 10K, while marathoners and half marathoners should incorporate longer intervals at or faster than goal race pace. Beginners should introduce short time-based intervals at a pace that is slightly faster than comfortable. Experienced runners should experiment with various interval workouts at a variety of race paces.

How?

Depending on the length of the intervals, the pace you run will often vary. Shorter intervals should generally be run faster–think at 5 or 10K race pace–than longer intervals which are run at threshold–one hour race pace–half or marathon pace. In all cases, the total distance or time of the combined intervals should not exceed what you’d run in the corresponding race. That is, you wouldn’t run 7K worth of intervals at 5K pace nor would you run 60 minutes worth of intervals at 10K pace. Be sure to warm up properly beforehand and complete a short cool down after the fact to aid recovery.

The following are but a few examples of popular workouts that incorporate intervals but the options are seemingly endless:

• 12-20 x 200m or 1 minute at 5K pace (or slightly faster) with 200m rest between
• 8-12 x 400 or 2 minutes at 5K pace with 400m rest between
• 6-10 x 800m or 3 minutes at 10K pace with 400m rest between
• 4-8 x 1K or 4 minutes at 10K pace with 500m rest between
• 3-6 x 1 mile or 5 minutes at 10K pace with 800m rest between
• 2-4 x 2K or 10 minutes at half marathon pace with 1K easy between
• Ladder: 1K – 1M – 2K – 1M – 1K at half marathon pace with 1K easy between
• Progression: 1K- 2K – 3K – 4K at marathon pace with 1K easy between