HOW FAST CAN I RUN A MILE? All Out Mile as I train towards a SUB 15 MINUTE 5K. - The Welsh Runner

Aug 13, 2025

Intro: This is a quick summary of HOW FAST CAN I RUN A MILE? All Out Mile as I train towards a SUB 15 MINUTE 5K from The Welsh Runner. It’s a great watch — we’re breaking it down so you can try the workout today. Be sure to check out the full video for all the details.

Key Points:

The coach uses a single “all‑out” mile on a road/track to gauge current speed and mental toughness.
Primary training focus is sub‑threshold* work: easy miles, long trail runs, and controlled 1‑mile repeats with short recovery.
Listening to your body and adjusting intensity after hard sessions (e.g., after a race or a hard mile) is emphasized.
Volume builds gradually: 10‑mile easy runs, 15‑mile long runs on hills, and occasional hill repeats to strengthen legs. This approach to building volume not only prepares you for a fast 5K but also builds a strong foundation for longer distances. In fact, many of these principles are essential for Mastering the 10K: Proven Training Plans, Pace Strategies, and How a Smart App Can Elevate Your Performance.

Workout Example: The core of this training block is a powerful interval session designed to build speed endurance. While this workout uses mile repeats, there are many ways to structure your sessions; you can learn more in our complete guide to Mastering Interval Training: Science-Backed Workouts and How a Smart App Can Personalize Them.

Here’s the specific workout from the video:

5 × 1‑mile repeats at a comfortably hard, sub‑threshold pace (just below lactate threshold). Keep each mile controlled—use heart‑rate or perceived effort rather than chasing a specific time.
Recovery: 1 minute easy jog or walk between repeats.
Progression tip: If you can’t hit the exact pace, aim for a slightly faster effort than the previous week (the video moved from 4 to 5 repeats).
Optional add‑on: After the repeat session, follow with a 10‑mile easy trail run or a 15‑mile long run to keep weekly mileage high (≈60 mi/week).

Practical Tips You Can Use Right Now:

Use a heart‑rate monitor to stay in the sub‑threshold zone (≈85‑90 % of max HR).
If legs feel “trashed” after a hard effort, cut the next run short (30‑40 min) or switch to easy miles.
Incorporate hill‑friendly routes to build leg strength without adding speed stress.
Keep a “listen‑to‑your‑body” mindset: adjust the plan on the fly, especially after injury or a hard race.

Closing Note: Try the 5 × 1‑mile repeat with 1‑minute recovery today—customise the pace to match your current fitness using the Pacing app. Keep building your aerobic base and hill strength, and you’ll be on track for that sub‑15‑minute 5K. If you’re looking for even more workouts tailored to race day, be sure to read our guide on Mastering 5K Speed: Proven Interval Strategies to Cut Minutes off Your Time. Happy running