Interval Training

Alternating high-intensity efforts with recovery periods. Develops speed, VO2 max, and mental toughness.

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Understanding Interval Training

Interval training alternates between high-intensity running efforts and recovery periods. Classic examples include 800m repeats on a track, hill sprints, or timed efforts like 3 minutes hard / 2 minutes easy. It's the most time-efficient way to improve speed and VO2 max.

The physiological magic of intervals lies in accumulating time at high intensity without the unsustainable fatigue of one continuous hard effort. Running 6 x 800m at 5K pace gives you 3 miles of fast running that you couldn't sustain continuously. The recovery periods allow partial lactate clearance and heart rate recovery so you can repeat the effort.

Different interval structures target different systems. Short intervals (200–400m) develop speed and neuromuscular power. Medium intervals (600–1200m) build VO2 max. Long intervals (1600m–2000m) develop speed endurance and lactate clearance. A well-designed training plan uses all three throughout the season.

Key Facts: Interval Training

Key facts and insights about interval training that every endurance athlete should know.

Interval training improves VO2 max more

Interval training improves VO2 max more effectively than any other workout type

Short intervals

Short intervals (200–400m) target neuromuscular speed; long intervals (1K–2K) target lactate clearance

Recovery between intervals should be 50–

Recovery between intervals should be 50–100% of the work interval duration

Most plans include 1–2 interval sessions

Most plans include 1–2 interval sessions per week with at least 48 hours between them

Pro Tips: Interval Training

Run each interval at the same pace — avoid starting too fast and fading on later repeats

The recovery jog matters: keep moving at easy pace, don't stop completely

Warm up with 10–15 minutes of easy running and strides before starting intervals

If you can't hold pace on the last 1–2 repeats, you started too fast

Frequently Asked Questions About Interval Training

It depends on the purpose. For VO2 max development, run 800m–1200m repeats at 5K race pace. For speed endurance, run 1600m–2000m repeats at about 10K pace. For raw speed, run 200m–400m repeats at mile to 1500m race pace. A VDOT calculator based on a recent race time will give you precise targets.

No. You can run intervals on roads using GPS or by time (e.g., 3 minutes hard, 2 minutes easy). A track is convenient for measuring exact distances but not required. Some runners prefer road intervals because they simulate race conditions better.