5K Base Phase: The Easy Run with Strides

This article is part of our 5K session series. Each article covers one session: how it’s structured, what it does, when to run it, and what to run around it. This one is a short easy run with a small but important addition at the end: strides.

The session at a glance

Where it fits: the four phases of 5K training

We split 5K training into four phases. Each has a different job:¹

• Base (6–8 weeks): build your aerobic engine and get your legs used to regular running. Almost everything is easy.
• Build (4–6 weeks): add harder sessions, like threshold intervals, on top of the base.
• Peak (2–3 weeks): sharpen with work at or near 5K race pace.
• Taper (7–10 days): cut the volume, keep a little speed, and arrive at the start line fresh.

The easy run with strides is a base-phase session that keeps its place through every phase. In the taper, it’s often the last session you run before race day.

Purpose, goal and target

Purpose: to build aerobic fitness with the easy run, and to keep your legs used to moving quickly with the strides, without any of the fatigue of a proper speed session.

Goal: a relaxed 3.1-mile (5km) run in zone 2, followed by strides that feel fast, smooth and controlled.

Target: run the easy part at zone 2 heart rate and a 6 out of 10 effort, the same as the zone 2 approach to base building, walking if your heart rate goes too high. Run the strides at around 85–90% of your top speed, quick rather than flat-out, so you finish each one feeling you had more to give. Form matters more than speed: tall posture, relaxed shoulders and hands, quick light steps.

What strides are

A stride is a short, controlled acceleration, usually about 20 seconds or 90–110 yards (80–100 meters). You build up smoothly over the first few seconds, hold a fast, relaxed pace, then ease off gradually. It isn’t a sprint, and it’s too short to push your heart rate high or build up lactate in any meaningful way.

Because they’re so short and followed by full recovery, strides give your legs the stimulus of fast running at almost no fatigue cost.

How to run it

1. Walk for 5 minutes, then ease into a slow jog.
2. Run 3.1 miles (5km) in zone 2, keeping the first mile deliberately slow. Walk if your heart rate alert goes off.
3. Walk for 1–2 minutes at the end of the run to let your heart rate settle.
4. Find a flat, clear stretch of about 110 yards (100 meters). A grass field, a quiet path or the straight of a track all work well.
5. Run 4–6 strides:
   • Build up over the first 5 seconds.
   • Hold a quick, relaxed pace for about 10 seconds.
   • Ease off over the last 5 seconds.
6. Walk slowly back to the start after each one. Take at least a minute; you should feel fully recovered before the next stride.
7. Finish with a few minutes of easy walking.

Beginners can start with 4 strides and add one every week or two up to 6. If you’re new to running and still finding continuous jogging hard, leave strides out until you can run the full 3.1 miles (5km) comfortably.

What it does to your body

The easy run does the same job as every zone 2 run: more mitochondria, more capillaries, a stronger heart, and gradual toughening of tendons and bones.²

The strides add something the easy run can’t. Fast running is a skill, and strides train your nervous system to recruit muscles quickly and in the right order, which helps you run efficiently when you pick up the pace later in the plan.

They also help running economy, which is how much energy you use at a given pace. Short, fast efforts and explosive training have been shown to improve it, and in one study of trained runners, adding explosive work improved 5K time without any change in aerobic fitness.³ Strides are a gentle, low-risk version of that stimulus.⁴

Most runners take quicker, shorter steps during strides, which makes them a useful reminder of what light, efficient running feels like; see does cadence really matter? for more. And they get your legs ready for harder sessions. Runners who only ever run slowly often find their first interval session feels awkward and heavy, so strides in the base phase prepare you for the threshold work in the build phase.

Timing

Run this session once a week in the base phase. You can add strides to a second easy run once the session feels routine. It works well 1–2 days before a harder or longer session, because the strides wake your legs up without tiring them.

The strides always go at the end, after the easy run, when you’re warm. Never run them cold. Choose flat, even ground: soft grass is kind on your legs, and wet or uneven ground is where you might slip.

Keep the session through build and peak. In the taper, a short easy run with 4 strides 1–2 days before the race is a classic way to arrive feeling sharp.

Matching sessions

In the base phase, this session sits alongside the 4.3-mile (7km) zone 2 easy run and the steady tempo run:

Placing strides two days before the steady tempo run means your legs have had a reminder of faster running before the week’s harder effort. A short core workout fits well after this session, since it’s short and leaves time and energy to spare.

Back-to-back: the day before and the day after

The day before: rest, cross-training or another easy run is best, and the zone 2 easy run is fine. Avoid a hard session. Strides on tired legs lose their quality, and tired legs are more likely to pick up a strain at speed.

The day after: rest or active recovery is best. A harder session such as the steady tempo run or, in the build phase, threshold intervals is fine, since the strides are short enough that they shouldn’t leave you tired. If your calves or hamstrings feel tight or sore the next day, your strides were too fast or you didn’t recover fully between them, so run the next set a little slower.

Common mistakes

• Sprinting. Strides are 85–90% effort, not flat-out. Full sprints raise the risk of a hamstring or calf strain and add fatigue you don’t need.
• Skipping the recovery. Walk back slowly and fully recover; strides with short rests turn into an interval session.
• Running them cold. Always do them at the end of the run, not the start.
• Tensing up. Clenched fists and raised shoulders waste energy, so think fast and relaxed.
• Running the easy part too hard. The zone 2 rule still applies to the 3.1 miles (5km). Strides don’t give you permission to rush the easy run.

Adding strides to your week

The session is a 3.1-mile (5km) zone 2 easy run followed by 4–6 strides of about 20 seconds, each with a full walk-back recovery. Keep the strides quick but relaxed, around 85–90% of top speed and never a sprint. They improve coordination and running economy at almost no fatigue cost and prepare your legs for the harder sessions later in the plan. Run them at the end, on flat ground, ideally 1–2 days before a harder session, and keep the session in your plan through every phase, including the taper.

This article is general information, not medical or coaching advice. If you feel chest pain, dizziness or unusual breathlessness while running, stop and talk to a doctor.

References

1. Issurin VB. New horizons for the methodology and physiology of training periodization. Sports Medicine, 2010. doi.org
2. Holloszy JO, Coyle EF. Adaptations of skeletal muscle to endurance exercise and their metabolic consequences. Journal of Applied Physiology, 1984. journals.physiology.org
3. Paavolainen L et al. Explosive-strength training improves 5-km running time by improving running economy and muscle power. Journal of Applied Physiology, 1999. doi.org
4. Barnes KR, Kilding AE. Strategies to improve running economy. Sports Medicine, 2015. doi.org