Last year, one of my coached athletes (let's call him Dave) was running the Manchester Marathon. He started strong but faded badly and started cramping in the last 10k. He finished 30mins slower than his target time.
Seven months later in Valencia, he ran almost 45 minutes faster.
Here’s what we changed in those six months that made the difference.
Build Consistency First: The Foundation of Endurance Running
Looking at Dave's training program, he had some good sessions and a few good long runs, but there were too many gaps in his training.
So we built mileage gradually, mostly easy pace, and focused on keeping the running consistent and regular. It didn't have to be fast or hard, just regular pavement pounding. Cumulative aerobic mileage at easy pace is one of the most robust predictors of marathon improvement and these consistent weeks started to stack together.
Speed Work: How to Build a Buffer Between Your 5K Pace and Marathon Pace
The biggest issue was speed, as Dave's marathon pace was too close to his 5K/10K pace. This meant that any surge in effort, a hill, a crowded section, or going out slightly too fast would spike his lactate quickly and increase the risk of blowing up in the final miles. He needed a buffer.
We improved his 5K/10K by adding two top end focused speed sessions per week. The sessions themselves don't need to be complicated. Here's what we used:
• Strides
4-6 × 20-second accelerations at the end of an easy run. Build to about 90% effort, hold briefly, decelerate smoothly. Full recovery between each.
• 200s / 400s Sprint Sessions
An example of this would be building up to:
10 × 200m at roughly mile pace, 60-90 seconds rest between reps
8 × 400m at 5K pace, 90 seconds rest - these should feel controlled and repeatable, not all-out
• Hill Repeats
6–10 × 60-90 second hill efforts at hard but not sprint effort, jog back down as recovery. Builds leg strength and running economy without the pounding of track work.
• 1k and 2k Intervals
For this we built up gradually to:
5 × 1K at 5K pace, 2 minutes rest or
4 × 2K at comfortably hard effort (between 5K and 10K pace), 3 minutes rest
These sessions should leave you tired but not destroyed. If the last rep is significantly slower than the first, then you went too hard.
As his top-end speed improved, marathon pace started to feel controlled. Race pace was now well within his range rather than pushing against the ceiling of it.
Marathon-Specific Long Runs: Where Race Day Is Actually Rehearsed
You can't expect to hold a goal marathon pace for 26.2 miles if you've never practised it under fatigue. Some of your long runs need to include it if achieving a particular pace is truly your race goal. This will also give you a great indicator of whether your chosen pace is a feasible goal for your current fitness level.
Start small, maybe just a 5min interval in the middle or near the end of the run to simulate that race fatigue, but you can build this to sessions like:
The Classic:
This one is HARD and should only be attempted once or twice in your training cycle near the peak of your training.
4 × 5K at marathon pace, 1 mile easy float in-between, easy miles to finish to distance.
The Progression Run:
Start easy, build to race pace then ease down for the last couple of miles to recover. A good starting point when adding race pace to your long run as you can adjust the session very easily.
The Fast Finish:
This helps simulate the final miles of the race and help you understand race pace under fatigue. Keep your long run easy until the final 2-3miles, then run these at or slightly above marathon pace.
That’s where you practice fuelling, pacing, and holding form late in the race - your real race practice sessions.
Most runners chase fitness. The athletes who break plateaus chase consistency, speed reserve, and race-specific preparation. If Dave's story sounds familiar, start with the simplest change first: run more regularly and build from there.