INTERVAL RUNNING: THE KEY TO SPEED AND POWER

What Makes Interval Training Different?

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, too long, or not slowing down enough in 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. Think of them as the high-intensity component that complements your easy runs and long runs.

What Interval Runs Should Feel Like

Getting the right effort level for your intervals is crucial for building speed without burning out. Here's what you should be aiming for:

• Hard effort – You should be pushing your limits but make sure you are still in control
• Heart rate in Zone 4-5 – Pushing close to your limit (80-100% of max HR)
• Short, intense bursts – Intervals typically range from 400m to even 2 km (1/4 to 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.

To get the most out of your intervals, using a heart rate monitor (More accurate HR) or a running watch like the Polar Pacer or garmin forerunner 225 helps you stay in the right zone and control your timing more accurately.

Not sure what your heart rate zones are? Use this Hr Zone Calculator or read the Full Guide to Heart Rate Zones to estimate them.

Why Interval Runs Matter for Your Training

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

Here's 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

The key is understanding that intervals aren't about going as fast as possible, they're about teaching your body to handle sustained high-intensity efforts. This translates directly to better race performance at any distance.

Pro tip: Intervals are like speed practice. They teach you what it feels like to push hard for short periods, which builds the foundation for faster race paces.

How to Do Interval Runs the Right Way

Getting your interval strategy right can make the difference between breakthrough workouts and burnout. Here's your step-by-step approach:

Choose Your Interval Type

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.

Choose the Right Interval Length

The ideal interval length will depend highly on your race distance, generally longer intervals are more effective for longer race distances.

• Short intervals (200-400m or 30 sec to 1 min): Focus on speed and power. These are great when training for short race distances like the 5K
• Medium intervals (600-1000m 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 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

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.

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

Stick to 1 (At Most 2) Sessions Per Week

Interval training is the most intense session of the week. Doing too many sessions can lead to overtraining, so space them out properly in your schedule and don't overdo them.

The Bottom Line on Interval Training

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.

The key is finding that sweet spot where you're working hard but still in control. When you nail your intervals, you'll notice that race pace starts to feel more comfortable, and you'll be able to handle faster efforts for longer periods.

Ready to add intervals to your training? Start with one session per week, focus on staying in the right heart rate zone, and watch how your speed and race performance improve. The high-intensity effort will pay dividends when it matters most.