Whether you’re a sprinter or a long-distance runner, getting nutrition right is vital to optimising performance, promoting recovery, overall good health and reducing the risk of injuries.

In fact, the most likely contributors to fatigue in endurance sports like long distance running are carbohydrate depletion (aka “hitting the wall”) and dehydration (1).

To understand nutrition for running, let’s first look at energy. It’s helpful to think of your body as a car that relies on fuel to run. However, your body is much more sophisticated, with the ability to adapt to be more fuel efficient the more that you train.

Furthermore, you can expand the capacity of your fuel tank (meaning you can run for longer) with training periodisation and smart nutrition planning.

Are you training for an event or looking to maximise your running potential? Book an appointment with our dietitian today for a personalised plan and learn how to periodise nutrition with your training goals.

Nutrition for runners: sources of energy

Carbohydrates

Your body primarily uses sugar in the form of glucose to produce energy for movement i.e., the contracting and relaxing of your muscle fibres. Your body stores a small amount of sugar in the form of glycogen in your liver and muscles (2).

Due to how quickly it can be broken down into glucose, you will deplete your glycogen stores first when you run. Therefore, it is important to eat enough carbohydrates to replenish your glycogen supply before your next session.

Protein

Protein is another source of energy. If your body runs out of sugars and fatty acids to burn, it can break down the protein in your muscle tissue and convert it into sugar.

High intensity training like sprinting or long-distance running can result in more micro-tears in your muscle tissue. Getting enough protein is vital for runners as it contributes to muscle repair and recovery.

Fat

Fat is the most energy dense source of energy i.e., it contains the most calories/kilojoules per gram.

The drawback of fat stores is that they are not as readily accessible when you exercise as it takes time to break down fat tissue into fatty acids and convert it to glucose. The longer that you run and the more your glycogen stores deplete, the more you switch to fat burning mode (3).

Therefore, healthy fats are still important for replenishing your energy stores and have anti-inflammatory properties to support your recovery after a run.

How you approach diet and nutrition depends on the type of running you do

What should I eat before my run?

• Short distance: <30 minutes

Eating a light carbohydrate-based snack and drinking beforehand is optional. You may choose to withhold food to avoid discomfort or an upset stomach during the run.

• Moderate distance: 30-90 minutes

A carbohydrate-based snack is recommended 30-60 minutes before the run.

• Long distance: >90 minutes

A full meal 2-3 hours beforehand, followed by a snack 30 minutes beforehand is strongly recommended

Pre-run snack and meal ideas

Why should I limit fat and fibre before a run?

Whilst getting plenty of healthy fats and fibre is important for your general health and well-being, it is not recommended to consume too much before a run.

This is because fat and fibre can slow down digestion. In the case of fuelling for a long run, you want to maximise your body’s glycogen stores, so simple, easy to digest starches are best.

Do I need to eat during my run?

Eating is optional for runs shorter than 60 minutes. For runs longer than this, you will need to replenish with 30-60g of carbohydrates per hour (4).

Consider bringing fast acting carbohydrates like medjool dates, bananas, energy gels/chews and sports drinks on long runs.

How do I refuel my body after my run?

What you eat after a run is just as, if not more important than what you eat beforehand.

You no longer need fast acting sugars after a race or training session, so focus on a nutrient dense, balanced meal consisting of complex carbohydrates, protein and healthy fats to fuel your recovery.

Post run meal ideas

• Ham, cheese and salad sandwich or wrap with whole grain bread
• 2 egg vegetable and feta omelette with 2 slices of sourdough toast
• Burrito bowl with 3/4 cup brown rice, beef, avocado, salsa and ½ cup black beans
• 120g salmon, 1 roast sweet potato and green veggies
• 1 cup of cooked whole meal pasta with 1 cup of lean beef bolognaise

Remember, the longer the run, the larger your carbohydrate portions need to be. Finding the right carbohydrate portion that works best for you can take some trial and error.

If you’re finding your recovery difficult or constantly feeling fatigued, it is best to speak to a dietitian to help you troubleshoot.

What is carb loading?

There is evidence that a nutrition strategy called “carb-loading” is effective for increasing your glycogen capacity if you are training for long distance runs like half or full marathons (5).

Carb loading has been shown to improve performance by 2-3% for runs longer than 90 minutes (6).

Speak to our dietitian if you would like a personalised plan on this.

Is fluid intake important to help improve my running performance?

Adequate hydration is essential for optimal running performance. Dehydration not only decreases exercise performance but can lead to exercise related collapse, heat stroke and heat exhaustion and even kidney failure (7).

On a shorter run, it is not necessary not replace the fluids lost during the session. For runs between 30-60 minutes long, you may sip on water throughout, but refrain from drinking large amounts of fluids at once.

For runs longer than 60 minutes, you should consider sipping on electrolyte replacement drinks during the session, but no more than 700ml fluids per hour.

Rehydration is most crucial and you will need to replace 150% of the amount fluid lost within 4-6 hours after your run. You can determine this by working out the change in weight before and after your run.

The bottom line

For runners, eating a healthy balanced diet with adequate carbohydrates, protein and fat is paramount to maintaining your body’s energy stores and supporting repair and recovery, therefore bringing about your peak performance.

If you are a long-distance runner, fast acting, readily available energy in the form of glycogen is your best friend before a run.

Rehydration after a training session or race is more important than replacing the fluids lost during the run, with electrolyte replacement drinks not necessary unless runs are longer than 60 minutes.

Are you training for an event or looking to maximise your running potential? Book an appointment with our dietitian today for a personalised plan and learn how to periodise nutrition with your training goals.

References

1. Jeukendrup, A., 2011. Nutrition for endurance sports: Marathon, triathlon, and road cycling. Journal of Sports Sciences, 29(sup1), pp.S91-S99.
2. Murray, B. and Rosenbloom, C., 2018. Fundamentals of glycogen metabolism for coaches and athletes. Nutrition Reviews, 76(4), pp.243-259.
3. Melzer, K., 2011. Carbohydrate and fat utilization during rest and physical activity. e-SPEN, the European e-Journal of Clinical Nutrition and Metabolism, 6(2), pp.e45-e52.
4. Jeukendrup, A., 2014. A Step Towards Personalized Sports Nutrition: Carbohydrate Intake During Exercise. Sports Medicine, 44(S1), pp.25-33.
5. Mata, F., Valenzuela, P., Gimenez, J., Tur, C., Ferreria, D., Domínguez, R., Sanchez-Oliver, A. and Martínez Sanz, J., 2019. Carbohydrate Availability and Physical Performance: Physiological Overview and Practical Recommendations. Nutrients, 11(5), p.1084.
6. Hawley, J., Schabort, E., Noakes, T. and Dennis, S., 1997. Carbohydrate-Loading and Exercise Performance. Sports Medicine, 24(2), pp.73-81.
7. Armstrong, L., 2021. Rehydration during Endurance Exercise: Challenges, Research, Options, Methods. Nutrients, 13(3), p.887.