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Interval Running – The Key to Speed and Power

Interval training is running with short bursts of high-intensity running followed by recovery periods. These runs push your cardiovascular system, improve speed, and teach your body to handle faster paces for longer periods. Unlike easy or long runs, intervals are meant to be hard but controlled, maximizing your potential in a short amount of time.

By Quentin van Bentum | Last updated Feb 25, 2024

A Full Breakdown

Interval running is one of the most effective ways to increase speed, build endurance, and improve running economy. By alternating between fast efforts and recovery periods, you train your body to run at higher intensities without overdoing it.

A common mistake runners make? Running intervals too fast, to long or not swowing down enough the recovery phase. The hard efforts should be challenging but maintainable, and the recovery should be long enough to allow a quality next rep.

Intervals are beneficial for all distances—from 5Ks to marathons—because they train your body to clear lactate more efficiently, meaning you can hold faster paces for longer.

What Interval Runs Should Feel Like

  • Hard effort – You should be breathing heavily but still in control.
  • Heart rate in Zone 4-5 – Pushing close to your limit (80-100% of max HR).
  • Short, intense bursts – Work intervals typically range from 400m to even 2 km (1/4 – 1 1/4 mile) or 1 to 6 minutes, depending on what race distance you are training for.
  • Equal or slightly longer recovery periods – Recovery should allow just enough rest to perform the next rep at a high level.

If you’re unable to complete the final reps at a strong pace, you may need to adjust recovery time or slow down the intensity slightly.

Graph of Heartrate Zones (Zone 4-5 Marked)

Why Interval Runs Matter

Intervals aren’t just about speed—they improve your anaerobic capacity, endurance, and ability to sustain high effort over time.

How Interval Runs Help You Improve:

Increase speed – Teaches your body to handle faster paces.
Boost VO₂ max – Improves how efficiently your body uses oxygen.
Enhance lactate threshold – Helps delay fatigue at higher speeds.
Improve race performance – Key for running strong at any distance.

How to Do Interval Runs the Right Way

  1. Decide between time-based or distance-based intervals.
    Time-based intervals (For example, 2-minutes fast, 2-minutes slow) are great for general fitness and effort-based training.
    Distance-based intervals (For example, 600m fast, 300m recovery) are best when training for a specific race.

  2. Choose the right interval length.
    Short intervals (200-400m (1/8-1/4 mile) or 30 sec – 1 min): focus on speed and power. These are great when training for short race distances like the 5k.
    Medium intervals (600-1000m (1/3-2/3 mile) or 2-4 min): improve race pace and endurance. These are great when training for medium race distances like the 10k or half marathon.
    Long intervals (1000m-2000m (2/3- 1 1/4 mile) or 4-6 min): Improve aerobic endurance and build mental toughness. These are great when training for long race distances like the marathon or ultramarathons.

  3. Run at the right intensity – Each interval should feel hard but controlled. You should be breathing heavily but still able to complete all reps at a consistent effort.

  4. Take proper recovery
    Recovery should be active: light jogging or walking.
    For short intervals: Recovery should be equal to or slightly shorter than the effort.
    For longer intervals: Recovery can be slightly longer to allow for quality reps.

  5. Stick to 1-2 sessions per week – Interval training is intense. Doing too many sessions can lead to overtraining, so space them out properly in your schedule.

The Key Takeaway

Interval training is one of the best ways to become a faster, more efficient runner. When done right, it builds speed, endurance, and race-day confidence.

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