A long run can look controlled on the watch and still fall apart in the final kilometres. Heavy legs, fading concentration, an unexpected stomach issue and a pace that slips despite good fitness are often fuelling problems, not fitness problems. The best fuelling tips for long runs are not about finding one magic gel. They are about building a repeatable system that supports the work your training plan requires.
For serious endurance athletes, nutrition is part of session execution. It affects the quality you can hold late in a progression run, how well you absorb the following week’s training, and whether race-day decisions feel familiar rather than risky.
Best fuelling tips for long runs: start with the session goal
Do not fuel every long run identically. A relaxed aerobic run, a hilly trail session and a long run with marathon-pace blocks create different carbohydrate demands. The longer and harder the session, the greater the case for deliberate fuelling.
For runs lasting less than 75 to 90 minutes at an easy effort, a normal pre-run meal may be enough for many athletes. Once runs extend beyond that point, or include sustained quality, take carbohydrate during the session. This protects training quality and teaches your gut to process fuel while running.
The old idea that every long run should be under-fuelled to build toughness is costly. There is a place for carefully planned low-carbohydrate availability work in some programmes, but it is not a default strategy. If you repeatedly finish key long runs depleted, you compromise pace, recovery and the ability to execute the next important session.
Build your carbohydrate intake progressively
Carbohydrate is the primary fuel for higher-quality endurance work. A practical starting point for long runs is 30 to 45 grams of carbohydrate per hour. Athletes running for more than two hours, particularly with race-pace efforts included, will often benefit from building towards 60 grams per hour.
For marathon and ultramarathon preparation, some athletes can tolerate 60 to 90 grams per hour, and occasionally more. That higher range usually requires a mix of carbohydrate sources, such as glucose and fructose, rather than relying on one source alone. It also requires practice. Trying to take in 90 grams per hour for the first time on race day is an efficient way to find the nearest toilet.
Start with what your stomach handles well, then increase one variable at a time. Add a gel, increase the carbohydrate concentration in your drink, or shorten the time between feeds. Give each adjustment several long runs before judging it. A sound fuelling plan is built through repetition, not one successful session.
Use a clock, not hunger
Hunger is a poor guide once you are deep into a run. By the time you feel flat, you may already be behind on carbohydrate. Begin fuelling early, usually within the first 20 to 30 minutes, then feed at regular intervals.
That may be a gel every 25 to 30 minutes, smaller chews every 15 minutes, or carbohydrate drink taken consistently from a bottle. The format matters less than the total amount and your ability to execute it without disrupting rhythm. Set an alert on your watch if you need one. Simple systems hold up when fatigue rises.
Eat before the run without overcomplicating it
The pre-run meal tops up liver glycogen after an overnight fast and provides useful carbohydrate for the early part of the session. For a morning long run, most athletes do well with a familiar, low-fibre meal one to three hours beforehand. Toast with honey or jam, oats, a banana, rice, or cereal can all work well depending on timing and preference.
The closer you are to the run, the smaller and simpler the meal should be. A larger meal needs more time to digest. If an early start makes a full breakfast impractical, have a small carbohydrate snack before leaving and take your first fuel early in the run.
Avoid turning breakfast into a nutritional experiment. High-fibre foods, excessive fat, large protein serves and unfamiliar supplements can slow digestion and increase gastrointestinal risk. A meal that looks perfect on paper is useless if it leaves you hunting for a public toilet 20 minutes into the session.
Hydrate for conditions, not fear
Australian conditions can change the equation quickly. A cool early start may become a hot, exposed final hour, especially on long routes with limited shade. Sweat losses vary dramatically between athletes, so there is no universal number of millilitres to drink per hour.
Begin well hydrated, carry enough fluid for the route, and drink to a considered plan that reflects duration, weather and your personal sweat rate. On hotter or longer runs, a sports drink can provide both fluid and carbohydrate. Sodium is also useful when sweat losses are high, sessions are prolonged, or you know you are a salty sweater.
More fluid is not automatically better. Overdrinking can be as problematic as drinking too little. Weighing yourself before and after selected long runs can help establish your approximate sweat loss in particular conditions. Use that information to guide future sessions, rather than copying another runner’s bottle strategy.
Train the gut as deliberately as the legs
Your gut adapts to fuelling under running stress. That is why athletes who can comfortably eat and drink late in a race usually practised it across months of training. The process should be progressive, especially if you have a history of bloating, cramps, reflux or diarrhoea.
Match race-like fuel to race-like sessions. If you plan to use gels, use them during long runs. If your event provides a particular sports drink, test it. If you will carry soft flasks, a vest or a belt, wear it. The goal is not merely to prove a product is tolerable. It is to make the entire sequence automatic: opening the gel, taking water, managing the packaging and continuing to run with purpose.
Caffeine deserves the same caution. It can improve alertness and perceived effort for many athletes, but dose, timing and gut response are individual. Trial it in training, not when a race result is on the line.
Match fuel density to your logistics
A city long run with regular drink fountains allows a different setup from a remote trail route. If water is readily available, gels or chews may be convenient. If water is limited, a carbohydrate drink may be more practical. In a trail ultra, real food can offer welcome variety, but it can be harder to chew and digest when effort is high.
Plan the route around your fuelling needs rather than hoping a servo, café or fountain appears at the right time. Know what you will carry, where you can refill, and what happens if the session runs longer than planned. This is basic preparation, and it reduces avoidable stress.
Practise fuelling at race intensity
Easy running can hide a weak nutrition plan. The real test is whether your intake still works when you lift the pace, run into a headwind, climb, or reach the final hour. Include fuelling rehearsal in long runs that feature marathon pace, threshold work or race-specific terrain.
This is where some athletes discover that a product tolerated at easy pace becomes difficult at competition effort. The solution may be smaller, more frequent serves, extra water with each gel, a different product texture, or a lower concentration in the bottle. Adjust the plan with precision rather than abandoning it after one poor experience.
Recover well enough to train again
Your fuelling strategy does not end at the final kilometre. After a demanding long run, eat a meal containing carbohydrate and protein within the next few hours, rehydrate according to losses, and include some sodium if the session was hot or especially sweaty. You do not need to panic-eat the moment you stop, but delaying food for half a day makes recovery harder than it needs to be.
Review the run while the details are fresh. Did you take in what you planned? Did energy stay stable? Did your stomach tolerate it? Was the bottle volume enough for the weather? Treat the answers as training data. Over a block of consistent work, those small adjustments create the confidence to race with intent.
The strongest long-run fuelling plan is the one you can execute calmly, week after week, when the session gets hard and the conditions are less than perfect.