Owen PalmerBy Owen Palmer

Updated November 2026

High impact interval training, usually shortened to HIIT, alternates short bursts of hard running or effort with recovery periods. This guide shows you how to build a session, set intensity targets you can actually hit, and progress without overloading your legs. By the end, you will have a repeatable workout you can run on a track, road, or treadmill.

Understand the Work-to-Rest Ratio

Most high impact interval sessions use a work-to-rest ratio between 1:1 and 1:2. A beginner might run 30 seconds hard and recover for 60 seconds, while a more experienced runner might run 3 minutes at 5K effort and recover for 90 seconds. The shorter the rest, the harder the session feels, so match the ratio to your current fitness rather than copying a demanding plan from someone else.

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Set Intensity Targets You Can Repeat

Hard does not mean all-out on every rep. Aim for an effort you can hold across all repeats. A useful starting point:

  • Beginner: 80–85% of maximum heart rate, or an effort you rate around 7 out of 10.
  • Intermediate: 88–92% of maximum heart rate, or about 8 to 9 out of 10 on the effort scale.
  • Advanced: Race-pace or faster repeats, with rest kept long enough that splits stay within a few seconds of each other.

Use a watch or chest strap for heart rate if you have one. If not, the effort scale works well. Your last rep should feel about as hard as your first.

Build Your First Session Step by Step

  1. Warm up for 10 minutes with easy jogging, then 4 to 6 relaxed strides of 15 seconds each.
  2. Run 6 repeats of 60 seconds at your target effort, followed by 90 seconds of walking or easy jogging.
  3. Cool down for 5 to 10 minutes at a conversational pace.
  4. Log your split times or heart rate for each rep so you can compare sessions.

After two or three weeks, add one repeat or extend each work interval by 15 seconds. Change only one variable at a time.

Manage Impact and Recovery

High impact interval training stresses the calves, shins, and tendons more than steady running does. Keep at least one full rest day or an easy aerobic day between sessions, and limit high-intensity work to two days per week when you are starting out. If you notice sharp pain, swelling, or pain that worsens during a run, stop and consult a doctor or sports medicine professional before continuing.

Common Mistakes

  • Starting every rep too fast and fading by the third interval.
  • Cutting recovery short because the workout feels easy at first.
  • Running hard sessions on consecutive days.
  • Skipping the warm-up, which makes early reps feel far harder than they should.
  • Adding volume and intensity at the same time.
  • Running shoes with good cushioning: Interval sessions load your legs quickly, so well-cushioned trainers help manage the extra stress. View on Amazon
  • Chest heart rate strap: Gives accurate readings during fast repeats, which wrist sensors can lag on. View on Amazon

FAQ

How many times a week should I do high impact interval training?

Most beginners do well with one or two sessions per week, separated by easy running or rest days. Experienced runners may add a third session during specific training phases.

How long should a high impact interval session last?

A complete session, including warm-up and cool-down, usually takes 25 to 40 minutes. The hard work itself often makes up less than 15 minutes of that time.

Can beginners do high impact interval training?

Yes, if they start with short work intervals, longer recovery periods, and lower effort. Anyone with a heart condition, joint problems, or other health concerns should check with a doctor first.

Conclusion

High impact interval training works best when you choose a sensible work-to-rest ratio, keep your effort repeatable, and allow recovery between sessions. Start with one session a week and progress slowly. Track your splits or heart rate so you can see improvement over time.

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Owen Palmer

About Owen Palmer

Owen Palmer is part of our editorial team and reviews and edits our speed & interval running guides, checking product details against manufacturer specifications and owner feedback.