Half Marathon workout and PR in the process, but... - Seth James DeMoor

Aug 13, 2025

Intro

This is a quick summary of Half Marathon workout and PR in the process, but… from Seth James DeMoor. 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

Threshold focus: The run is a 13‑mile threshold effort aimed at hitting roughly 5:22–5:23 per mile pace (around 5:20 target).
Race‑time simulation: Seth recommends doing hard workouts at the exact time your target race starts (e.g., 9 am) to train your body to be fast early in the day.
Warm‑up structure: A few easy miles plus a set of strides get the legs ready.
Environmental factors: Cold, rain, and allergies can affect breathing and shoe feel, but they’re manageable with proper clothing (buff, gloves) and a flexible mindset.

Workout Example

1️⃣ Warm‑up – 2–3 easy miles (easy conversational pace)
2️⃣ Strides – 6–8 × 100 m fast strides with full recovery
3️⃣ Main set – 13‑mile threshold run @ ~5:22‑5:23 min/mi (≈8:35 min/km)
   • Aim to stay even; slight slowdown in the last mile is OK.
4️⃣ Cool‑down – ½–1 mile easy jog + stretch

Tip: If you’re training for a marathon, treat this as one of the last hard efforts before tapering. Adjust the distance or pace to match your current fitness level.

Closing Note

Give this threshold run a try, tweak the paces in the Pacing app to suit your own recent race times, and see how it sharpens your legs for race day. Remember to watch the full video for Seth’s deeper insights, and keep pushing toward that next PR! 🚀