Long runs are often the training sessions most like the event you are preparing for. They are a testing ground to help you avoid surprises on race day.
As your longest sessions, they can expose gaps in fuelling and require more recovery. Plan nutrition to support performance at 100% and recovery.
There are many things to practise: fuel availability, hydration, maintaining blood glucose, managing glycogen, replacing fluids and electrolytes, body-composition goals where appropriate, carbohydrate loading and pre-race breakfasts.
Your needs also change at different points in the session.
Without knowing you, we cannot personalise every detail, but these tips may help you prepare your long runs.
Find your balance.
In endurance sport, getting enough energy to train and recover while pursuing fat loss, when appropriate, requires care. Weight loss is not a goal every runner needs.
Long, lower-intensity sessions can use substantial fat as well as carbohydrate. Your Garmin might estimate 1200 kcal for a long run, but that does not mean replacing all 1200 kcal immediately. Consider total daily needs and the estimate’s uncertainty.
Reducing excess body mass can reduce joint loading, but deliberate weight loss is not universally beneficial. On a 15 km run, the original article estimates around 11000 steps with forces of 2–3 times body weight. These figures vary and are not an instruction to underfuel.
A deficit may be used for an appropriate fat-loss goal, but insufficient energy availability can harm health and undermine a high training volume.
In endurance sport, glycogen availability matters. Choose carbohydrates for the session and your tolerance: readily available sources are useful during exercise, while adequate overall intake replenishes stores. “Complex” and “low glycaemic index” are not the same classification.
Your muscles, joints and mind may be ready for 42 km, but your body still needs fuel to sustain the effort.
Think of filling a car’s tank. Understanding fuel use helps you decide what to eat beforehand and during training.
Allow digestion time, without starting hungry.
A useful habit is to avoid a large, undigested meal immediately before training or racing. Digestive and exercising tissues both need blood flow, and running soon after a heavy meal can cause discomfort. This does not mean starting fasted or with empty glycogen stores.
Similarly, during exercise, choose fuel types and amounts that support performance and are comfortable to digest.
For pre-workout ideas, this post may help.
Train your gut, too.
Gastrointestinal problems are common on long runs. The good news is that practising fuelling can improve tolerance.
You would not swap bikes or shoes with a teammate on the start line, would you?
Fuel is just as individual. Intestinal absorption has limits, so learn what works for your body and each training session or race.
Anti-inflammatory medicines, excessive fructose for your tolerance, dehydration, large amounts of fat and poorly tolerated fibre can contribute to digestive problems.
Gradually practise foods or supplements before and during training. Responses to caffeine are highly individual: the original article cites 1–6 mg/kg, but suitability and dose need assessment rather than unsupervised escalation through that range.
Nothing new on race day. Test options in training and learn how you tolerate ingredients such as fibre.
Just as you would not enter a marathon without training, do not introduce unfamiliar foods or products without checking tolerance.
Skipping fuel in training because “I don’t need it”, then taking 3 gels per hour in a race because “now I do”, is not a good rehearsal.
Use your heart-rate monitor as a guide.
It provides context about intensity, not a direct measurement of fuel use. Generally, higher intensity increases heart rate and carbohydrate demand. That information can help plan meals.
Harder training often uses more carbohydrate, while easier work may use a greater proportion of fat. But a long, easy session can still use substantial glycogen.
Duration and intensity are key to pre-, during- and post-workout nutrition. A monitor helps you understand both.
Find fuelling options that suit you
On sessions or events over 90 minutes, fuelling often needs to begin during the effort rather than waiting until the finish.
Carbohydrate intake supports energy production and can delay fatigue. Glycogen use and storage also depend on training status, muscle mass, hydration and other factors.
Whole fruit and nuts may be less convenient at high intensity because of fibre, fat and digestion time. Gels, sports drinks, chews or homemade options can work, depending on exercise and tolerance. The original article proposes a 3:1 sugar mixture for efforts over 120 minutes; this is not a universal prescription. Maltodextrin is a glucose polymer, while Palatinose (isomaltulose) and fructose are different carbohydrates, not types of maltodextrin.
Plan fuel before exhaustion rather than waiting for it. Absorption and effects vary by product and context; the original reference to about 30 minutes is a rough estimate, not a fixed delay for every supplement.
Remember: your fuelling needs are individual, so allow time to experiment. Test sports drinks, homemade bars and different commercial products in training.
Do not forget recovery
Some people find eating immediately afterwards difficult. Allow a little time to settle, then begin replacing what you need.
Include nutritious meals supplying protein, carbohydrates, vitamins and minerals, including sodium when losses justify it. Commercial recovery products often use carbohydrate-to-protein ratios such as 2:1 or 3:1, but actual amounts matter more than a universal ratio. A dairy smoothie with instant oats and fruit can be convenient. Add suitable fat sources, such as nuts, as tolerated; salted nuts also provide sodium.
Glycogen restoration takes time, so spread food across recovery rather than expecting one meal to do everything. Full recovery may take days.
Read Post-workout: what to eat after training for more information.
Ready to get more from your long runs? Do not leave nutrition unfinished. Explore our online sports nutritionist services.
