Race Faster by Training Slower, with 2:28 Marathoner Josh Sambrook

Summary

Host Floris Gierman welcomes Leeds-based runner and coach Josh Sambrook, whose 2:28 marathon personal best came from an approach that runs against the usual instinct to make training runs fast: accumulating a great deal of easy mileage instead.

Josh recalls starting out with conventional training—long runs, intervals, and rest days. His first marathon, in Cambridge, ended in 3:24 after he set off too quickly and struggled through the final eight miles. After several races in the 3:05–3:20 range, he changed tack, focusing on weekly mileage and average pace rather than a fixed menu of workouts.

Training and pacing

Josh’s easy-run heart rate has fallen from about 150 beats per minute to roughly 130–140 as his fitness has improved. He says his marathon effort begins around 166 bpm for the first half, then rises by about one beat per minute per kilometre, reaching around 186 near the finish.

He now often runs more than 200 kilometres a week, typically splitting the distance into two or three shorter runs. This structure fits around work more easily than a single very long outing. In one March, he logged about 1,000 kilometres.

Josh discusses a marathon predictor based on average weekly distance and pace in the eight weeks before a race. He says it has closely predicted his own results, though runners may need to account for their personal tendency to outperform or fall short of its estimate. He also describes a coaching tool that tracks training and estimates what remains to reach a goal.

He cautions that increasing mileage—or concentrating it into a few hard days—can raise injury risk. His advice is to build gradually, listen to the body, and choose a schedule that fits one’s life and durability.

The case for easy running

Josh says speedwork can be useful but is not essential. In his own 2:28 build, only a small share of his training was near marathon pace. He argues that consistency and overall training load mattered more than occasional fast efforts.

Rather than assuming every runner has the same weakness, he recommends identifying what actually limits performance—such as muscular fatigue or cardiovascular strain—and tailoring cross-training or strength work accordingly.

Motivation and nutrition

Josh describes a training display that stays red until he completes his daily target, then turns green. A simpler written goal or another personal incentive can serve the same purpose.

For nutrition, he often runs before eating to practise relying on fat stores, and says he doesn’t take fuel during marathons. He stresses that this is what works for him, not a universal rule. He eats a vegetarian diet with plenty of fruit and vegetables, and also uses calorie-dense foods such as chocolate to support his high training volume.

Broad advice

Josh’s broad advice is to keep a record of training, review what seems to help, and adjust over time. Improvement, he says, comes from learning through successive races rather than expecting to get everything right at once.

Presenters and sources

• Presenter: Floris Gierman
• Guest: Josh Sambrook
• Sources and tools mentioned: Tanda Race Predictor; Strava; an unnamed Italian researcher’s marathon-prediction study; Josh’s coaching and training-tracking website