Interval Running Workout: 6 Sessions From Run-Walk to 1 km Repeats

Most runners meet interval training the same way. You read that speed work makes you faster, you head out, run the first rep as hard as you can, and by the third one you're walking with your hands on your hips, wondering how anyone finishes eight of these.

So you decide you're just not fast, or that intervals belong to people on track teams. Or you swing the other way and run every day at the same medium-hard pace, which leaves you tired all week and no quicker by the end of the month.

Neither is a talent problem. Interval running works when the session fits your level, the hard parts are run by feel, and the easy days stay easy. The six workouts below are built that way, from your first run-walk to 1 km repeats.

What Is Interval Training for Running?

Interval training is any workout that alternates a work interval, a set time or distance at a hard effort, with a recovery interval at an easy effort, and repeats the pair. In running, the work is faster running and the recovery is easy jogging, walking or standing still. Every interval workout has four parts: a warm-up, the work, the recovery and a cool-down.

The point of breaking the hard running into pieces is volume. You can run far more total minutes at a hard effort in short reps than you could in one continuous push, and those minutes are what drive the adaptation.

Run by Effort, Not by a Pace Chart

Pace charts assume you already know your race times and that every day is flat, cool and well rested. Effort works on hills, in the heat, on a tired Thursday and on a treadmill. These sessions use two simple gauges: the 0 to 10 rating of perceived exertion (RPE) and the talk test.

The talk test is more precise than it sounds. Foster and colleagues (2008), in the Journal of Cardiopulmonary Rehabilitation and Prevention, found that the point where people could no longer speak comfortably tracked the ventilatory threshold, and it moved with that threshold when fitness went up or down. For a full walk-through of the scale, see our guide to the rate of perceived exertion.

None of these sessions asks for 10 out of 10. All-out efforts belong to short sprints, and the last rep of any interval workout should look like the first one, not like the end of a race.

6 Interval Running Workouts by Level

Start with the first session that feels manageable, not the one that sounds most impressive. Every workout uses the same warm-up and cool-down unless it says otherwise.

• Standard warm-up: 10 minutes of easy jogging (or brisk walking for run-walk), then 4 relaxed strides of 15 to 20 seconds, building to a quick but smooth pace and walking back between them.
• Standard cool-down: 5 to 10 minutes of easy jogging or walking until your breathing settles.

1. Run-Walk Intervals (Interval Running Workout for Beginners)

If continuous running still feels out of reach, run-walk is your interval workout, and the walk breaks are the recovery intervals.

• Warm-up: 10 minutes of brisk walking.
• Work: 1 minute of easy running at RPE 5 to 6. You should be able to say a short sentence.
• Recovery: 2 minutes of walking.
• Reps: 6 to 8.
• Cool-down: 5 minutes of walking.
• Progress: when the last rep feels as easy as the first, move to 2 minutes running and 2 minutes walking, then 3 and 1. Two sessions at each step is a sensible pace.

The run segments here are steady, not hard. Walk breaks are a legitimate strategy in their own right, which we cover in our post on whether it's OK to take walk breaks while running.

2. 30-30s

Thirty seconds fast, thirty seconds jogging. It's the friendliest true speed session because no rep lasts long enough to fall apart, and it works on a road, a path or a field.

• Work: 30 seconds fast at RPE 8 to 9, about the effort you could hold for 5 or 6 minutes in a race. You can manage one or two words by the end of each rep.
• Recovery: 30 seconds of easy jogging. Keep moving.
• Reps: start with 10. Add 2 reps a week up to 20.
• Effort cue: the first three reps should feel almost too easy. If rep 8 is slower than rep 2, you started too hard.

The jog between reps is what makes this format work. Billat and colleagues (2000), in the European Journal of Applied Physiology, measured eight distance runners on a track. Alternating 30 seconds at the speed that elicits VO2 max with 30 seconds at half that speed kept them at their maximal oxygen uptake for an average of 7 minutes 51 seconds across about 19 reps. A single continuous hard run gave them only 2 minutes 42 seconds there.

3. The Pyramid

A pyramid climbs and then descends in rep length, so each half of the session feels different. The short steps teach speed and the middle step teaches you to hold an effort.

• Work: 1, 2, 3, 2 and 1 minutes hard.
• Effort cue: RPE 7 on the 3-minute rep (a few words at a time), RPE 8 on the 2-minute reps and RPE 9 on the 1-minute reps.
• Recovery: 60 seconds of easy jogging after the 1- and 2-minute reps, 90 seconds after the 3-minute rep.
• Progress: extend it to 1-2-3-4-3-2-1 minutes, with 2 minutes of recovery after the 4-minute rep.

Run the way down a touch faster than the way up. If you can't, the first half was too hard.

4. 400 m Repeats

The 400 m repeat is the classic track session, and a standard outdoor track is 400 m around the inside lane. On roads, use a measured loop or a GPS watch, and stick to flat ground.

• Work: 400 m at RPE 8 to 9, roughly your 5K race effort or slightly quicker. Most runners take between 1.5 and 3 minutes.
• Recovery: jog 200 m, or walk for 90 seconds if you need to.
• Reps: start with 6. Build to 8, then 10 over several weeks.
• Effort cue: aim for even reps. A fast first rep and a slow last one means the session ran you.

5. 1 km Repeats

Longer reps are the advanced end of interval training. They hold you near your highest oxygen uptake for longer, and they suit runners training for a 10K or a half marathon.

• Work: 1 km at RPE 7 to 8, about your 10K race effort. Most runners take 4 to 7 minutes.
• Recovery: 2 to 3 minutes of easy jogging.
• Reps: 3 to start, building to 5.
• No track? Run 4 reps of 4 minutes hard with 3 minutes of easy jogging between them. That's the 4 x 4 format from a Norwegian trial described below.

Don't move here until 8 reps of 400 m feel controlled. Long reps punish an optimistic start more than short ones do.

Treadmill Interval Workout

A treadmill takes pacing off your plate, which makes it the easiest place to run a ladder. This is session 6, and any level can use it by adjusting the effort.

• Warm-up: 10 minutes of easy jogging or brisk walking.
• Work: 5, 4, 3, 2 and 1 minutes hard, nudging the speed up a little at each step. Aim for RPE 7 on the 5-minute rep and RPE 9 on the last minute.
• Recovery: 2 minutes of easy jogging or walking after each rep.
• Cool-down: 5 minutes of walking.

Three treadmill details make a difference:

• Set the incline to 1%. With no air resistance, flat treadmill running costs less energy than running outside. Jones and Doust (1996), in the Journal of Sports Sciences, found a 1% grade matched the energy cost of road running for efforts of about 5 minutes at a range of speeds.
• Use the interval settings, or do it by hand. Most treadmills have an interval or custom program where you enter a work speed, a recovery speed and the durations. If yours doesn't, change the speed manually and start the change a few seconds early, because the belt takes time to speed up.
• Clip on the safety key and stay on the belt. Jumping onto the side rails at speed between reps is how treadmill falls happen. Slow the belt for recovery instead.

How Often Should You Do Interval Training? The 80/20 Rule

Once or twice a week, with the rest of your running easy. That ratio comes from watching what successful endurance athletes actually do. Seiler and Kjerland (2006), in the Scandinavian Journal of Medicine and Science in Sports, logged 318 endurance sessions by 11 nationally competitive junior skiers. About 75% sat in the easy zone below the first ventilatory threshold, 17 to 18% above the second threshold, and very little in between. That pattern is called polarized training, and the popular shorthand for it is 80/20.

Trials back the pattern up. Esteve-Lanao and colleagues (2007) gave 12 subelite runners five months of training with either about 80% or about 67% of their time at low intensity, holding the hard work equal. The mostly easy group improved its 10.4 km time by 157 seconds against 121.5 seconds. In 30 recreational runners, Muñoz and colleagues (2014) found a 5.0% 10K improvement on a 77/3/20 split against 3.6% on a plan heavy in medium efforts. That gap wasn't statistically significant for the whole group, but it was for the runners who stuck most closely to their plans. And Stöggl and Sperlich (2014) randomized 48 well-trained endurance athletes to four models for nine weeks: the polarized group gained the most VO2 peak, 11.7%. Our polarized training research review covers the full set of trials.

For your week, that means:

• New runners: one interval session a week, which can simply be the run-walk workout.
• Regular runners: one or two sessions a week, never on back-to-back days.
• Everyone: roughly 80% of your running time at easy, full-sentence effort. Count the warm-up, the recovery jogs and the cool-down as easy time.

What Is Interval Running Training Good For?

Interval running trains three things: your aerobic ceiling, how economically you run, and the speed you can hold before you have to slow down.

VO2 max. In Helgerud and colleagues' (2007) study in Medicine & Science in Sports & Exercise, 40 moderately trained men trained three times a week for eight weeks, with total work matched across four groups. Two interval groups raised VO2 max by 5.5% (15 seconds on, 15 seconds off) and 7.2% (4 x 4 minutes), while easy distance running and threshold running at the same total work did significantly less. A meta-analysis by Milanović and colleagues (2015) of 28 studies found both intervals and continuous training raised VO2 max a lot, with a small extra edge for intervals. Wen and colleagues (2019) pooled 53 randomized trials and found that reps of 2 minutes or longer, at least 15 minutes of hard work per session and programs of 4 to 12 weeks gave the largest gains. That's why the 1 km and 4-minute sessions sit at the top of the list. For the physiology behind those numbers, see our review of how to increase VO2 max.

Running economy. Economy is the oxygen you need to hold a given pace. In their review of strategies to improve running economy, Barnes and Kilding (2015) note that training history and total volume are thought to matter, and that high-intensity intervals on flat ground and uphill are frequently prescribed to improve it further, along with strength and plyometric work.

Endurance and speed. Does interval training build endurance? Yes, alongside easy mileage. In the Stöggl and Sperlich trial, the polarized group also lasted 17.4% longer on a ramp test to exhaustion and reached a 5.1% higher peak speed or power. Intervals sharpen an aerobic base. They don't replace one.

Fartlek, Hill Sprints and Tempo Runs

Three other formats get lumped in with intervals, and each has its own guide:

• Fartlek mixes faster surges into one continuous run, often by landmark or feel, and you recover by jogging instead of stopping. Our fartlek training guide has five unstructured workouts.
• Hill sprints are 8 to 10 second all-out efforts uphill with full recovery, a strength and power drill more than a fitness session. See our hill sprints protocol.
• Tempo runs hold one comfortably hard effort for 20 to 40 minutes, without recovery breaks. Our tempo run guide shows how to find that effort.

What Are the Negatives of Interval Training?

Intervals are strong medicine, which is also their downside. They cost more recovery than easy running, and they make it tempting to turn every run into a hard one. Running hard most days is the most common way runners end up sore, stale and injured.

The heart works harder too. In a Norwegian cardiac rehabilitation program, Rognmo and colleagues (2012) recorded 175,820 supervised exercise hours by 4,846 people with coronary heart disease. Cardiac arrests were rare in both kinds of training: 1 per 129,456 hours of moderate exercise and 1 per 23,182 hours of high-intensity intervals. The risk was low, but it was higher during the hard sessions, which is why anyone with heart disease or symptoms should get medical clearance before starting intervals.

How to Progress Safely

1. Change one thing at a time. Add reps, or lengthen the reps, or shorten the recovery. Never all three in the same week.
2. Move up slowly. Repeat a session until its last rep feels like its first, then progress. Two or three weeks per step is normal.
3. Keep easy days easy. If you can't talk in full sentences on an easy run, it isn't easy, and it eats into the recovery your next interval session needs.
4. Back off when the signs show up. Heavy legs for days, a resting heart rate that stays up, poor sleep or reps that keep slowing at the same effort all mean you should swap the next interval day for an easy run.
5. Stop immediately for chest pain or pressure, dizziness, unusual breathlessness or sharp pain in a joint or bone.

What Are Some Good Circuit Workouts for Runners?

A short strength circuit twice a week makes your legs more durable for interval days. Do it after an easy run or on a rest day, never right before an interval session. Run through this circuit two or three times with a minute of rest between rounds:

• Split squats: 8 to 10 per leg, bodyweight or holding dumbbells.
• Single-leg Romanian deadlifts: 8 per leg with a dumbbell, slow on the way down.
• Calf raises: 15 to 20, then 10 on one leg at a time.
• Glute bridges: 12 to 15, pausing at the top.
• Side plank: 20 to 30 seconds per side.
• Dead bug: 8 slow reps per side.

If you'd rather have that strength work planned for you, our comparison of the best strength training apps covers the options. FitCraft is one of them: its strength workouts use bodyweight and dumbbells, an AI coach demonstrates each exercise on an interactive 3D model and says your name during the workout, and the workouts adjust as you progress. Streaks and leaderboards help the two short sessions a week actually happen.

The Bottom Line

An interval running workout is hard running broken into pieces with easy recovery between them. Pick the session that matches your level, run the reps by effort so the last one looks like the first, and do one or two a week with the rest of your running easy.

You don't need to be fast to start. You need the right session and a week built around it. Do that for a couple of months and the paces that used to feel hard start to feel like yours.