ALL IN S2:E1 - BUILDING A RUNNER'S BASE - The Welsh Runner

Aug 13, 2025

Quick Summary

This is a quick summary of ALL IN S2:E1 – BUILDING A RUNNER’S BASE 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

Focus on building a solid aerobic base before tackling marathon‑specific work. 
Use a weekly heart‑rate test: run 1 hour at a steady pace (15 km/h ≈ 6:30 min/km) and track HR each Monday to see the heart‑rate drop as fitness improves.
Aim for high volume (≈ 80 mi / ≈ 130 km week) with double‑day runs (two sessions per day) to accumulate mileage while keeping each session easy.
Add a 5 km virtual race at about 4:50 min/mi (≈ 3 min/km) for a confidence boost.
Include hill loops with 1‑minute on/off intervals for strength, and keep the rest of the training steady and aerobic.

Workout Example

Monday – Baseline treadmill run
- 1 hour on treadmill at 15 km/h (≈ 6:30 min/km).
- Wear a chest‑strap HR monitor; record average HR.
- Repeat each Monday, aiming to lower the HR week‑over‑week.
Tuesday – Easy outdoor run
- 1 hour steady run, ~8.5 mi (≈ 13.7 km) at a comfortable, conversational pace.
Mid‑week double
- 30 min easy treadmill run at the same 15 km/h pace.
- Follow with a 30‑min easy run (12 km/h) as a recovery run.
5 km virtual race (once per week)
- Target pace ≈ 4:50 min/mi (≈ 3 min/km). Use it as a mental “race” to test fitness.
Hill loop session (once a week)
- Warm‑up 10 min easy.
- 1‑minute on/1‑minute off intervals for ~2 mi, then steady run to the hills.
- Push hard up the hills, recover on flats and down‑hills; repeat for a second loop.
Weekly mileage target: ~80 mi (≈ 130 km) spread over 5‑6 days, including a long run (≈ 1 hour) and a short recovery run each day.

Practical Tips

Keep the same shoes and treadmill speed for the Monday test to ensure a fair comparison.
Track HR and aim for a gradual drop each week; the lower the HR at the same pace, the fitter you are.
Use hilly routes to add strength without adding speed work.
If you’re not on metric, 15 km/h equals about 6:30 min/km (≈ 10:30 min/mile) and 4:50 min/mi equals 3 min/km.
Use the Pacing app to customize the paces to your own fitness level.

Closing Note Give this base‑building plan a try, tweak the paces to suit your own fitness in the Pacing app, and watch your heart‑rate drop as your aerobic fitness climbs. Keep showing up – the miles you log now will set you up for a strong marathon later. Happy running! 🚀