Why Your Long Runs Aren’t Working (and How to Fix Them) - Lee Grantham - Lee Grantham

Aug 13, 2025

*This is a quick summary of “Why Your Long Runs Aren’t Working (and How to Fix Them)” from Lee Grantham. 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

A long run should focus on either building aerobic base (easy zone‑2) or race‑specific pacing, not both at once.
Jumping from a very easy “steady” pace to marathon‑pace at the end of a 24‑mi run creates a sudden shock, increasing injury risk and reducing confidence.
“Steady” should be roughly 20 % slower than your marathon pace (e.g., 6 min/km if marathon pace is 5 min/km).
Gradually increasing the pace in the latter part of a long run or using segmented pace blocks builds confidence without over‑fatiguing.

Workout Example – 18‑Mile Segmented Run

Total distance: 18 mi (≈29 km).
Structure: 6 repetitions of a 3‑mile block.
- 2 mi at marathon pace (e.g., 5 min/km or 8 min/mi).
- 1 mi 10‑20 % slower (e.g., 5:30‑6 min/km).
Result: 12 mi at marathon pace + 6 mi at a slightly slower, recovery pace.

Alternative Options

24‑mi steady run: Run the whole 24 mi at 20 % slower than marathon pace (e.g., 6 min/km) to keep it truly aerobic.
Pure Zone‑2: 24 mi conversational, easy zone‑2 (no fast finish) for pure base building.

Closing Note Try one of these structures on your next weekend run, adjust the paces to match your own marathon‑pace targets in the Pacing app, and watch your confidence and speed grow. Happy running!