How to pack a running vest for a 20-mile long run

Twenty miles is the run that tells you the truth. It's long enough to expose a fuelling plan built on optimism, and long enough that anything badly packed will have three hours to work its way into your skin.

It's also the most valuable rehearsal in a marathon block. Not just for the legs — for the whole system. Kit, fluid, fuel, timings, and the small mechanical business of getting a gel out of a pocket when your fingers are cold and your coordination has gone.

A vest solves the carrying problem, but only if it's packed with some thought. Front pockets you can reach at pace. Weight spread rather than stacked. Fuel in the order you'll actually use it. Here's how to load one properly, how much to put in it, and what to pay attention to while you're out there.

Pack the vest around the plan, not the other way round.

Twenty miles takes most runners somewhere between 2:40 and 3:45. Target 60g of carbohydrate per hour as a working figure for a long steady effort, adjusting up towards 90g if you're specifically training your gut for a marathon target and you've built to it gradually. For a three-hour run at 60g/hr, that's around 180g of carbohydrate to carry.

That's a real amount of food, which is exactly why it's worth counting before you leave the house:

A worked example for a three-hour, 60g/hr run:

• Flask one: Passo — 22g of carbs, drunk across the first hour

• 0:40 — Limon (45g)

• 1:10 — Rosso (30g)

• 1:40 — Limon (45g)

• 2:10 — Doppio (22g + caffeine) for the closing miles

• 2:40 — Rosso (30g) 

That's 194g of carbohydrate, spread evenly, with the caffeine timed to allow full absorption and benefit until it earns its place. The high-carb gels do the heavy lifting so you're carrying five sachets rather than nine — which changes how a vest feels considerably, and changes how much rummaging you do at hour three.

If 60g/hr is new to you, don't start here. Build up across a training block: take one long run at 45g/hr, the next at 50, and so on. The gut adapts to what you ask of it, but not overnight.

Two 500ml flasks is the standard setup and covers most three-hour runs in British conditions, especially if your route passes a tap, a shop or a café you're prepared to stop at.

Plan the route around refill points rather than trying to carry everything. A litre of fluid is a kilogram on your chest — it's the single heaviest thing in the vest, and the one item where a bit of route planning saves you real effort.

Two flasks, two jobs:

• One with an electrolyte drink. Passo if you want 22g of carbohydrate alongside 275mg of sodium, so your fluid counts towards your fuelling. Solo if you'd rather keep 350mg of sodium with no added sugar and take all your carbs as gels.

• One plain water. Useful for washing a gel down, and for pouring over your head in July.

In cold weather you may feel less thirsty but you should still take fluid — dry winter air and hard breathing pull more out of you than the temperature suggests.

For a run of this length you want something that sits close, carries fluid at the front and doesn't move.

The STRYQ Hydration Running Vest is built around 500ml soft flasks in the front pockets, with adjustable top and bottom straps to pull the fit evenly across the chest and sides. There's room alongside the flasks for gels, a phone and keys, and reflective detailing for the dark end of the year — which, in the UK, is most of marathon training season.

If you're weighing up a running vest against a belt: a belt is the right answer for shorter runs where you're carrying a phone, a key and a couple of gels. Once you're adding fluid, several hours of food and a layer, the load belongs across your upper body instead of on your waist. A running belt and a vest aren't really competitors — most runners end up with both and pick per session.

Front pockets — flasks and the next 90 minutes of fuel.

Two 500ml soft flasks sit in the front pockets and are the heaviest thing you'll carry, which is why they belong high and close to your chest.

Alongside them: the first two gels and nothing else. These are the ones you'll take at pace without breaking stride, so they need to come out one-handed on the move. Everything else in the front pocket is competition for your fingers.

Side pockets — the middle of the run.

Gels three and four, plus a bar if you're carrying one. Slightly harder to reach, which is fine, because by then you'll probably slow to a walk for ten seconds anyway.

Back — everything you hope not to need.

Spare layer, the last gel, a card, tissues, phone if you don't want it at the front, and a small bag for used wrappers. A separate wrapper pocket sounds like overkill until you're two hours in and can't tell full from empty by feel.

Not in the vest at all: anything hard, sharp or bulky that you've been carrying "just in case" for the last six weeks without using it. Every long run is a chance to take one thing out.

This is where most vest complaints actually come from — not the vest, the setup.

Cinch it once you're loaded, not before. Adjust with full flasks and a full kit list, then check again after ten minutes when everything has settled and you've warmed up.

Even tension, top and bottom. If you tighten only the chest straps, the vest rides up. If you tighten only the lower ones, the flasks bounce. Pull them evenly.

Test the reach standing still. Every pocket you plan to use should open with one hand and no looking. If it doesn't, move what's in it.

Watch the layer interaction. A vest over a fitted top behaves differently from a vest over a jacket, and a jacket underneath changes where the straps sit. Whatever you'll wear on race day, wear it on the long run.

Balance beats tightness. If something is moving, redistribute the weight before you pull the straps in. A vest cinched hard enough to stop a badly balanced load will restrict your breathing long before it fixes the bounce.

Under the vest, socks still matter — three hours of repetitive movement finds every seam. Feet swell as the run goes on, so a pair that feels perfect at mile two can feel tight at mile sixteen.

A pair of properly shaped running socks with a low-profile toe seam, a secure heel pocket and cushioning where impact actually lands does more for the last five miles than most of what's in your pockets. Check the usual hot spots afterwards — back of the heel, ball of the foot, outside of the little toe. Redness or shiny skin is early information, not something to run through next week.

Most 20-milers happen between October and March, in weather that changes mid-run.

• A vest is not waterproof. It's water-resistant and quick-drying, which is a different thing. In sustained rain, put your phone in a small waterproof pouch before it goes in a pocket.

• Layers you can stow, not layers you have to wear. Gloves and a light shell that pack down into the back are worth their weight. A heavy jacket you'll carry for three hours isn't.

• Reflective detail plus a light. Reflective strips help drivers see you when they're already pointing at you. In genuinely dark conditions, add a light and think about the route as much as the kit.

• Cold fingers can't open packaging. Practise tearing a gel with gloves on. It sounds trivial; it isn't at mile fifteen in February.

It bounces. Check the load distribution first — flasks high and forward, spares at the back. Then even out the strap tension. Only then consider whether it's the wrong size.

It rubs. Usually a seam sitting against a seam. Change the layer underneath, move whatever hard object is pressing against that spot, and use anti-chafe balm on the contact point.

Your stomach turns. Almost always too much carbohydrate too quickly, or too concentrated a drink. Spread the intake more evenly, take gels with a few sips of water, and step the hourly target back for a run or two before building again.

The 20-miler is where recovery stops being optional. You've emptied glycogen stores and you'll want to do it all again in a few days.

• Inside the first hour: Nova Recovery Protein, built on a 3:1 carbohydrate-to-protein ratio for exactly this point in the day.

• Then a real meal, with carbohydrate at the centre of it.

• Rinse the flasks and the vest properly. Hand wash or a gentle cold cycle for the vest, air dried — leaving damp kit in a closed bag is how a good vest stops being a good vest. Flasks that have had a carbohydrate drink in them need rinsing the same day, not the next.

• Write down what happened. Which gel sat well, which pocket you fumbled, where the rub started, what you'd change. That note is the most valuable thing you bring back from a 20-mile run.

Count the carbohydrate first. Carry it in as few sachets as you can — high-carb gels earn their place here. Put the weight at the front, the next 90 minutes of fuel within reach, and the just-in-case items at the back. Cinch it loaded, test every pocket one-handed, and run the whole setup at least once before it counts.