One of the key elements in getting the most out of your interval workouts is choosing the right amount of recovery between repetitions.
Some people like to keep the recoveries short, reasoning that there is no resting at all during a race, so, as the saying goes, ”why practice resting?” Others feel that a longer recovery allows them to run faster and therefore get more “bang for your buck” during the time you spend on the track.
And the correct answer is …. they’re both right.
I’ll qualify this by saying it depends on the purpose of the workout. First of all, it’s important to make the distinction between interval training and repetition training. Many people think that any sort of repeated running on the track is classified as interval training. In reality, there are two very different types of workouts that are done on the track.
Interval training is comprised of relatively short distance runs with brief, active (ie. light jogging) recovery periods. What makes this kind of workout difficult is the brevity of the recovery periods. For example, as an interval workout for an advanced 10k runner, I might prescribe a session of 15 or 20x400m at approximately 10k race pace with a 100m jog between each 400m. Running 400m at 10k race pace isn’t much of a challenge, the difficulty arises when you have to do 20 of them with only about 40 seconds of jogging between the 400m runs.
With interval training, the main goal is to develop resistance by running fairly hard while keeping the recovery periods short, so if you’re struggling with this type of workout, rather than extend the recoveries, you should slow down a bit or reduce the number of repetitions.
Repetition training, on the other hand, involves longer runs at race pace and therefore requires correspondingly longer recovery periods. In fact, with repetition training, the recoveries aren’t all that important, the goal is to practice maintaining your race pace for relatively long periods of time. Taking longer recoveries allows you to do more work at race pace, and this is the main goal of this type of session.
An example of a repetition workout for the 10k runner I mentioned above would be 4 or 5x2000m at 10k race pace with 5 minutes of standing (as opposed to jogging) recovery in between. This type of running is actually the most race-specific training that you can do. Since the main goal is to maintain the correct pace, if you start to struggle in this workout, the best remedy is to take a longer rest between reps, say 6-7 or even 10 minutes.
Both types of workouts are effective training for a distance runner and you can do one of each on a weekly basis as you build towards a goal race.
What about longer reps with short recoveries, such as mile repeats with 400m of jogging or less between reps? That’s a fine workout as well, but it has a different purpose. Longer reps with short recoveries should be oriented more towards threshold pace (ie. the pace you can hold for about an hour in a race) rather than race pace. Trying to run these reps at race pace is extremely taxing and likely too hard for an individual training session. The type of effort required for running longer reps at race pace with short recovery periods is better reserved for actual races.
Longer reps with short recoveries at moderate pace is an excellent workout for early in the season when you’re building your basic endurance. When you get closer to your goal race, it’s time to extend the rest periods and focus on running as close to race pace as possible.