Long Run Fueling Experiments: What Worked and What Didn’t
Fueling on a long run looks simple until the distance stretches beyond a couple of hours. A gel that felt perfect at 90 minutes can become sickly at four hours, while a breakfast that worked before a flat road run may leave the stomach sloshing on technical trails. The useful lessons usually come from small experiments rather than one perfect race-day plan.
My approach has been to treat nutrition like pacing: test one variable, record what happened, and avoid making dramatic changes during a key training block. The aim is steady energy, a calm stomach and enough concentration to make good decisions when the legs are tired.
Australian conditions make the margin for error narrower. A long run through the Blue Mountains can combine steep climbs, exposed ridgelines and limited water access. A summer session around Melbourne may begin cool and finish hot, while a race morning in Queensland can feel humid before sunrise. Fueling has to account for the course, weather and the practical question of what can actually fit in a vest.
| Experiment | What worked | What did not | Adjustment |
|---|---|---|---|
| Water only for two hours | Simple and comfortable on easy winter runs | Energy faded late and recovery was poor | Add carbohydrate from the first hour |
| One gel every hour | Easy to remember and useful for moderate efforts | Too little for harder or longer sessions | Aim for a regular carbohydrate intake |
| Gels with water | Portable and predictable | Flavours became unpleasant after several hours | Rotate flavours and add real food |
| Homemade rice cakes | Mild taste and satisfying texture | Difficult to eat while climbing | Use them on runnable sections |
| Electrolyte drink | Helpful in heat and heavy sweat | Too concentrated when mixed strongly | Keep the drink moderate and separate from gels |
Starting With A Simple Baseline
The first useful experiment was deliberately boring: water, one familiar gel and an easy pace. This established whether the problem was the product, the effort level or the total amount of carbohydrate. Many failed long runs were really under-fueled runs disguised as stomach problems. When energy intake is too low, the body becomes stressed, pace changes and nausea can follow.
For most long aerobic sessions, I now begin eating earlier than feels necessary. Waiting until hunger arrives is unreliable because hunger often disappears once intensity rises. A small amount every 30 to 40 minutes works better than a large rescue dose at the halfway mark. This also spreads the work across the run, so the gut is processing manageable portions.
The baseline needs to include the same bottle arrangement, pack and route style used in races. Carrying two soft flasks in a vest feels different from drinking at a trail aid station. A run around Sydney’s Centennial Park allows easy access to water, whereas a remote section of the Larapinta Trail demands more conservative planning. The fuel plan should match those constraints.
Gels, Drinks And The Sweetness Problem
Gels were the most convenient option. They are light, easy to count and available in a wide range of carbohydrate blends. They worked especially well during tempo sections and races where stopping to unwrap food would break concentration. Taking a gel with a few mouthfuls of water also reduced the thick, sticky feeling that appeared when I swallowed one dry.
The limitation was flavour fatigue. Three hours into a run, a sweet citrus gel could taste intensely artificial, even when it had been enjoyable in training. Switching between neutral, fruit and lightly salted options helped. A carbohydrate drink also provided variety, though I learned to avoid making it too concentrated. Strong drinks combined with gels created a heavy stomach and increased the need to drink plain water.
Some products marketed in Australia are easier to find online than in local shops, which matters when a race plan depends on a particular brand. I now buy enough for a training block, then use the same products repeatedly before an event. This is less exciting than trying every new packet at a running expo, but it gives a clearer picture of tolerance and cost.
Real Food On Long Trail Days
Solid food became useful once runs moved beyond three hours. Small rice cakes, soft bars, bananas and jam sandwiches offered a break from gels and felt more like proper food. The best items were mild, low in fibre and easy to chew. A small piece eaten before a long climb worked better than trying to eat a full snack while breathing hard.
My biggest failure was carrying food that required too much attention. A dry muesli bar became difficult to swallow on a steep Blue Mountains ascent, and a large sandwich was crushed inside the vest. Real food needs to be cut into small pieces and packed where it can be reached without stopping. The ideal trail snack is less about culinary appeal than reliable access.
A race report from a difficult trail event reinforced this point: trail 50K lessons showed how quickly a sensible plan can be tested by fatigue, terrain and unexpected setbacks. Fuel is part of the wider system that includes pacing, navigation and the ability to keep making reasonable choices when the day stops going to plan.
Hydration, Heat And Electrolytes
Fuel and hydration are connected, but they are not interchangeable. Drinking more water does not replace carbohydrate, and taking electrolytes does not provide enough energy for a long race. I found better results by deciding separately how much carbohydrate, fluid and sodium the session required, then combining them in a practical way.
In cooler weather, I can manage a steady run with less fluid and a few gels. In an Australian summer, that approach falls apart quickly. A humid Gold Coast morning, a hot Canberra trail or a long exposed road section near Adelaide can produce substantial sweat loss before the runner feels thirsty. Heat also raises perceived effort, so a pace that normally feels easy may make food harder to tolerate.
I have stopped trying to replace every gram of sweat loss during the run. That target is impractical and can encourage overdrinking. Instead, I use thirst, weather, session length and previous sweat patterns as guides. For a long outing, I carry a known amount, identify refill points and avoid arriving at the final hour with an empty bottle. An electrolyte tablet is useful when the drink is otherwise plain, but it is not a substitute for a full nutrition plan.
Turning Experiments Into A Race Plan
The experiments became useful when I recorded them in a simple training note. I write down start time, distance, temperature, approximate carbohydrate intake, fluid, effort and stomach response. A short comment such as “gel at 80 minutes, nausea after climb” is enough. There is no need to turn every long run into a laboratory trial.
Patterns emerged after several weeks. Low intake was linked with fading concentration and slow recovery. Large doses caused stomach discomfort. Real food helped on very long runs, while gels were better for shorter hard efforts. Eating on a schedule reduced the temptation to wait for a crisis. These findings made the race plan less complicated because I had already removed the options that repeatedly failed.
The most durable lesson is that fueling is a pacing decision. If the first hour is too quick, digestion suffers later. If the runner waits until exhaustion, even a good product may arrive too late. A sensible plan leaves room for weather, aid-station delays and changing effort. It also includes a backup: an extra gel, a familiar snack or a refill point marked on the course map.
For the next long run, I will carry one carbohydrate source, one small solid snack and a measured drink, then record the timing and stomach response immediately afterwards.