How To Run A Sub 20 5k (while running a sub 20 5k) - Ben Parkes

Aug 13, 2025

This is a quick summary of How To Run A Sub 20 5k (while running a sub 20 5k) from Ben Parkes. It’s a great watch — we’re breaking down his key advice so you can start training today. Be sure to check out the full video for all the details.

Key points

Pacing is everything. Aim for an even-split pace of about 3:56–3:57 per kilometre for the first 4 km. If you have energy left in the tank, use it to “kick” the final kilometre and finish strong.
Outsmart your GPS. Watches can be a few seconds off, so it’s wise to run slightly ahead of your target pace. For example, if your goal is 3:57/km, try holding a 3:55–3:56/km pace to build a buffer.
Build your base. A solid foundation is crucial. Aim for a weekly mileage of 45–60 km, consisting mostly of easy runs supplemented with key speed sessions.
Incorporate core speed sessions. To truly get faster, you need to add dedicated speed work. These sessions are classic examples of interval training, which is designed to boost your lactate threshold and top-end speed. For a deeper dive, explore our guide on Mastering Interval Training: Science-Backed Workouts and How a Smart App Can Personalize Them. Key workouts include:
- 10 × 400 m repeats run faster than your goal 5K pace.
- 5 × 800 m repeats run at your goal 5K pace.
- Regular tempo runs and weekly strides/drills to improve your form.
- You can find more workout ideas in our complete guide to Mastering 5K Speed: Proven Interval Strategies to Cut Minutes off Your Time.
Plan your training block. An 8 to 10-week training block is usually enough time to get sub-20 ready if you’re starting from a 22:30 – 23:00 5K time. Once you crush your 5K goal, you can apply the same structured principles to longer distances; our guide to Mastering the 10K: Proven Training Plans, Pace Strategies, and How a Smart App Can Elevate Your Performance is a great next step.
Prepare for race day. Always warm up with a 2 km easy jog and dynamic stretches. Stay hydrated and be sure to fuel properly 2–3 hours before the race.

Workout example from the video

1. Race-day pacing

0.00–4.00 km: Hold a steady 3:56–3:57 / km pace (even split).
4.00–5.00 km: Finish strong. If you have the energy, aim for ~3:45 / km.

2. Key training session (once per week)

10 × 400 m @ ~10–15 s faster than your 5K goal pace, with a 90 s easy jog in between.
OR 5 × 800 m @ your goal 5K pace, with a 2 min recovery jog.
Include 6–8 × 100 m strides and form drills after your easy runs to improve running economy.

Closing note

Give this training structure a go, tweak the paces to match your own speed in the Pacing app, and watch yourself get closer to that sub-20 5K. Good luck and enjoy the run