Fast 400s quality

Running economy

Time~35m

Distance6.2 km

DifficultyModerate

Route: Run quality sessions on the FLATTEST route you have. Your routes now average ~14 m of climb per km — nearly three times your historical average — and goal pace on that terrain is a different, much harder session than the one written.

Calibrated by your 5K best effort (23:55 on 08-27, measured by Strava): threshold 5:03–5:15 · 1K reps 4:40–4:50 · 400s 4:22–4:35 /km — trust these over the printed bands.

Ground you knowwithin reach of 6.2 km

6.0 km · flat, 7 m/km

steepest descent −10 m in km 3 · run once · best 5:59/km

6.5 km · flat, 6 m/km

steepest descent −6 m in km 5 · run once · best 5:45/km

5.7 km · flat, 2 m/km

steepest descent −6 m in km 5 · run once · best 5:46/km

5.7 km · steep, 29 m/km

steepest descent −16 m in km 3 · run once · best 6:48/km

Instructions

Warm-up

11 km easy warm-up6:10–6:45 /km

Intervals × 7

2400 m fast4:15–4:25 /km

3200 m slow jog

Cooldown

41 km easy cool-down6:15–6:50 /km

This week's quality slot is already done (w6_q_tempo_sandwich on 2026-09-19) — marking this one replaces it.