Running Interval Workouts: Four Sessions, the Right Pace and the Mistakes to Avoid

Intervals are the quickest way to add speed to your running, as long as you dose them right. Here are four sessions, a simple way to pick your pace and a clear answer on how often to do them.

Intervals are the session most runners associate with getting faster, and with burning legs. Running interval workouts alternate between periods of hard running and periods of rest or easy jogging. Simple on paper, but it's easy to go too fast, do them too often or skip the warm-up. Below you'll find four concrete sessions, a way to judge pace without heart rate zones and advice on fitting intervals into your week.

This guide is for you if you run for fitness, are training for a race or are preparing for HYROX, where the runs between stations demand that you hold pace on tired legs.

What are intervals?

An interval session is made up of work periods and recovery periods. During the work you run faster than you could sustain in one continuous effort. During recovery you settle enough to repeat that effort with good quality.

The point is that you can spend more total time at a high speed than if you tried to run the whole distance at that pace. That challenges your heart, lungs and legs. It's also demanding, which is why intervals should be part of your week, not your whole week.

Intervals, fartlek and tempo runs

Classic intervals have a set length and a set recovery, such as 6 x 800 metres with a 2-minute jog. Fartlek is a looser version where you speed up and slow down by feel or terrain. A tempo run is a longer stretch at a steady, hard but controlled pace. All three have their place, and one of the sessions below is a tempo run.

How fast should you run?

You don't need a heart rate monitor to hit the right pace. The simplest tool is the talk test: how much can you say while running? Combine it with a 1 to 10 effort scale, where 1 is a walk and 10 is everything you've got.

The golden rule: your last rep should be roughly as fast as your first. If you fade badly at the end, you started too hard. Finishing with a little left in the tank beats limping through the final reps.

Four running interval workouts to start with

Every session begins with a warm-up and ends with a cool-down, covered further down. The numbers are suggestions. Do fewer reps the first time and build from there.

1. Short intervals: 30/30s

Run 30 seconds fast, then jog or walk for 30 seconds. Start with 8 to 10 reps and work towards 15 to 20 once it feels manageable. You get plenty of speed without any single rep becoming long and heavy, which makes this a great first interval session.

On a track or measured stretch: 10 x 200 metres, jogging back slowly as your recovery.

2. Long intervals: 4 x 4 minutes

Run four minutes at a pace you can only just hold evenly, then jog easily for two to three minutes. Four reps is enough. If you prefer distance, 4 to 5 x 1 km works the same way.

This one hurts differently from short reps. The effort builds throughout each interval, so it's easy to go out too fast. Let the first minute feel almost too easy.

3. Hill repeats

Find a hill that takes 60 to 90 seconds to run up, steep enough to feel it but not so steep you have to walk. Drive with your arms, keep your steps short and walk or jog back down as recovery. Start with 6 reps and build towards 10.

Hills give you a high effort at a lower speed, which many runners find kinder on the legs than fast intervals on the flat. They also build strength in your calves and quads, something you'll notice in HYROX when you have to run straight after the sled.

4. Tempo run

After your warm-up, run 20 minutes at a steady pace where you can get out short sentences but not hold a conversation. Too tough? Split it into 2 to 3 x 8 to 10 minutes with a two-minute jog between.

Tempo runs feel less dramatic than intervals, but they're one of the best ways to hold a faster pace for longer. They're also easy to overcook. The right pace feels "comfortably hard".

This is where it helps not to stare at your watch. TANK logs your runs with GPS, distance, pace and intervals, and a voice reads out your time and pace at every kilometre so you can keep your eyes on the road.

How often should you do intervals?

For most recreational runners, one interval session a week is plenty to begin with. If you run three or four times a week, you can eventually do two hard sessions, for example one interval workout and one tempo run. Everything else should be easy.

• Keep at least one easy day between hard sessions. An easy jog or a rest day.
• Rotate sessions week to week. Short intervals one week, hills the next.
• Progress one thing at a time. More reps first, more speed later.
• Plan around your lifting. Avoid heavy leg day right before an interval session.

If you're new to training in general and want to fit running and strength into the same week, a workout plan for beginners can help you build a base before adding more intervals.

Warm-up and cool-down

Intervals without a warm-up feel harder and increase the chance of something tweaking. Allow about fifteen minutes before your first rep.

1. Jog easily for 10 to 15 minutes.
2. Do a few simple mobility drills: leg swings, hip circles, lunges.
3. Run 3 to 4 strides of 80 to 100 metres, building speed gradually, then easing off.
4. Walk for a minute, then start the session.

After the last rep, jog or walk easily for 5 to 10 minutes until your breathing settles. It won't necessarily make you less stiff tomorrow, but it's a good way to end the session under control.

Common interval mistakes

• Going out too fast on rep one. The classic. The rest of the session becomes a fight and quality drops.
• Making every run hard. Run medium-hard every day and your intervals are never truly fast and your easy runs are never truly easy.
• Cutting recovery short. Recovery is part of the workout. If you don't recover, you lose speed and it turns into a tiring steady run.
• Chasing pace in the wrong conditions. Headwind, heat, ice and hills all make the same effort slower. Run by feel instead.
• Doing too much too soon. Add reps gradually rather than doubling up overnight.
• Running through pain. Fatigue is normal. Sharp or worsening pain isn't. Stop, back off and see a professional if it doesn't settle.

How to know it's working

Repeat the same session a few weeks apart and compare. If you hold the same pace but it feels easier, or you can add a rep without losing quality, you're on the right track. You may also notice it on easy runs, where your usual pace takes less effort.

Be patient. Intervals give a quick sense of progress early on, but the big gains come from doing them consistently over months, with plenty of easy running around them.