Interval training: The art of speed and endurance

In this article, you'll learn everything you need to know about interval training so you can improve your performance - whether you're an experienced athlete or just starting out. We'll introduce you to various interval workouts, from the classic 8x400 meters to challenging units like 10x1 kilometer. Each workout has its own purpose and is designed to specifically activate certain energy systems and muscle groups to improve your speed, endurance and strength.

Why interval training?

Interval training is one of the most effective ways to improve both aerobic and anaerobic capacity. By alternating between high-intensity efforts and recovery periods, you can force your body to adapt and get stronger. This approach will not only help you run faster, but also maintain your speed over longer distances.

Important variables: speed and recovery

Before we dive into specific workouts, it's important to understand the two main variables that define any interval training: speed and recovery.

Speed: The pace at which you run each interval can vary greatly depending on your training goals. Whether you're aiming for a sprint, race pace, or something in between, the speed you choose will determine which energy systems are activated and how your muscles respond.
Recovery: The length and type of recovery between intervals is just as important as the pace. Longer recovery periods allow for near-complete recovery, allowing you to push harder each interval. Shorter recoveries keep your heart rate up, simulate race conditions, and challenge your endurance.

Classic intervals: 8x400 meters

Let's start with the classic 8x400 meter workout, typically on the track, with recovery phases in between.

Speed: Run each 400-meter interval at a pace that is faster than your 5k race pace, but not quite a sprint. This pace should be challenging but doable across all eight reps.
Recovery: Recovery time can vary. A short recovery (30-60 seconds) emphasizes aerobic endurance, while a longer recovery (2-4 minutes) allows you to focus more on speed and power.

Why it works: This workout gets your body used to faster speeds, improving your efficiency and allowing you to run faster for longer periods of time.

Endurance building: 10x1k intervals

For those training for longer distances like half marathons or marathons, 10x1k interval training is a great way to build endurance while maintaining speed.

Speed: Run each 1k interval at your 10k race pace or slightly faster. The goal is to maintain a steady, challenging pace without pushing yourself to the limit.
Recovery: Take a 90-second to 2-minute jog or walk break between intervals. This allows for partial recovery while keeping your heart rate up.

Why it works: By running multiple 1k intervals at a challenging pace, you train your body to clear lactate more efficiently, delaying fatigue and allowing you to maintain a faster pace for longer periods of time.

Variety: ladder intervals

Ladder intervals provide variety and challenge by combining intervals of increasing and then decreasing distance, e.g. 200m, 400m, 800m, 1k and then back down again.

Speed: Start the shorter intervals at a faster pace and slow down for the longer ones. When the distances get shorter again, pick up the pace again.
Recovery: Recovery times can be adjusted depending on the interval length. Shorter rest periods for shorter intervals and longer rest periods for the longer intervals will help maintain intensity.

Why it works: This varied approach challenges your pacing strategy and forces your body to adapt to different intensities, making you a more versatile runner.

Advanced Challenge: 3x2k with 1k Float

For experienced athletes who want to push their limits, the 3x2k with 1k Float workout is a powerful combination of speed and endurance.

Speed: Run the 2k intervals at your threshold pace – hard but sustained. The 1k float pace should be faster than an easy jog but slower than your interval pace.
Recovery: Allow yourself a 2-3 minute easy jog break between 2k intervals.

Why it works: This workout simulates race conditions, where maintaining a strong pace after a hard effort is crucial. It also teaches you to recover while keeping moving, which is excellent preparation for competition.

Adapting intervals to your goals

The versatility of interval training is one of its greatest advantages. You can customize the workouts to meet your specific goals, whether you're preparing for a 5k, a marathon, or an ultra-distance race.

For speed: Shorten interval length and increase tempo. Add longer recovery periods to focus on speed and power.
For endurance: Lengthen intervals and shorten recovery time. This keeps your heart rate up and simulates race conditions, improving your ability to maintain a strong pace.
For versatility: Combine different interval lengths and intensities in a single workout. This dynamic approach challenges your body in many ways and prevents training plateaus.