Why the Wall Waits Around Twenty Miles

Almost everyone who lines up for a spring marathon has heard about the wall. It is not a myth and it is not a character flaw. It is a fuel problem, and pacing decides how quickly you run into it. Your body stores roughly ninety minutes to two hours of readily available carbohydrate as glycogen in the muscles and liver. Run at a sensible, even effort and you will burn a mix of glycogen and fat, topping up with gels, chews or sports drink as you go. Run the first ten miles faster than you trained for and you will drain that store long before the finish.

The warning signs are usually clear. A sudden heaviness in the legs that no amount of grit shifts, a wobble in your stride, a strange chill, and a growing sense that walking would be lovely. By the time you feel it, the deficit is already there. The trick is to make sure you never build one.

Start Slower Than Your Goal Pace, On Purpose

If your target is a four-hour marathon, that is roughly 9:10 per mile or 5:41 per kilometre. A 3:30 goal is about 8:00 per mile or 4:59 per kilometre. Whatever your number, plan to run the first three to four miles fifteen to twenty-five seconds per mile slower than target — around ten to fifteen seconds per kilometre. It will feel almost insultingly easy. That is the point.

There are good reasons not to trust those early miles. Race-day adrenaline, a crowded start, cool morning air and the company of hundreds of other runners all push you along faster than you intend. In the Waveney Valley, a gentle downhill stretch out of town can add another few seconds without you noticing. Banking time early rarely works; the debt is collected with interest somewhere past twenty miles.

• Miles 1–3: hold back deliberately, settle your breathing, let the field spread out.
• Miles 4–13: find your goal pace and sit on it, checking splits rather than feelings.
• Miles 14–20: hold effort steady as the course and the day warm up.
• Miles 20–26.2: if you have fuelled and paced well, this is where you start passing people.

Learning What Pace Actually Feels Like

Numbers on a watch are only half the job. You need to know what your goal pace feels like in your legs, in your breathing and in your shoulders on a tired day. Training runs on the lanes around Bungay are perfect for this — the loop out towards Earsham and Ditchingham, the quieter roads towards Mettingham and the Ilketshalls, or the flat tarmac paths and towpaths along the Waveney when you want something predictable.

• Effort, not ego. Learn the difference between comfortably hard and honestly hard. Marathon pace should feel controlled and conversational-adjacent, never breathless.
• Marathon-pace blocks. Drop three or four miles at goal pace into the middle of a long run so the pace becomes familiar when you are already tired.
• Long runs with a purpose. Finish the last three miles of a twenty-miler at goal pace. This rehearses both fuelling and self-control.
• Hills count double. On undulating lanes, hold effort steady and let pace drift. Chasing splits uphill is how good plans unravel.
• The chat test. If you cannot speak a full sentence on an easy run, you are going too fast. Save the hard work for the sessions that need it.

A Simple Race-Day Plan to Protect Your Legs

Decide your split strategy before the day and write it on your wrist or set it as a watch alert. An even pace is the safest starting point; a slight negative split — the second half a little quicker than the first — is the mark of a well-judged marathon. Take your first gel before you feel you need it, usually around forty-five minutes, then keep to a regular schedule you have already tested in training.

If the day turns warm or windy, adjust the goal rather than the effort. A blustery headwind along an exposed stretch of the valley can cost you twenty seconds a mile for no extra fitness gain. Run the effort you trained for and let the clock do what it does.

Community Running Makes Pacing Easier

Bungay punches well above its weight for runners. Between the town's running club, the Saturday morning free 5k on the edge of town and the informal groups who meet on weekday evenings, there is almost always someone to train with. That matters more for pacing than people expect.

A group keeps you honest. It is much harder to blast off too fast when you are mid-conversation with someone who has run twenty marathons and knows exactly what the first mile should feel like. Long Sunday runs become sociable rather than gruelling, and the shared miles out through the lanes teach you more about sustainable effort than any spreadsheet. If you are training for a spring marathon, joining a few group runs in January and February will do more for your pacing than another solo tempo session.

Rehearse Everything Before Race Day

Use the final long runs to practise the whole package: the pace, the fuelling, the kit, the shoes. Nothing new on race day. Practise taking gels while running, practise drinking from cups, and practise holding back when you feel strong. Then taper properly, sleep well, and arrive at the start line with a plan you trust.

Pacing is not about being cautious. It is about spending your energy where it counts — in the last six miles, when the crowds are loud and the finish is close, and the runners who started sensibly are the ones still moving forward.