Nutrition for Runners - the science of it

Nutrition is an important parameter to be considered in long distance running and before we talk about the nutrients required by a runner, it is very important to understand the science behind nutrition         

Performance is a combination of Training & nutrition. Any imbalance in the above equation will not lead to desired results


Macronutrients are essential for our day to day living/survival. The key macronutrients that we require are listed below

1)   Carbohydrates

Carbohydrates are an important macronutrient and it is used as a source of fuel for all. Carbs are basically sugar based molecules that are converted into glucose, stored as glycogen and used as fuel, whenever required. On an average, the body can store about 2000 calories of carbs.

 Have you ever wondered why runners hit the wall at 32 kms? The human body typically burns 60-65gms of carbs/km and runners can run up to 32kms without any fuel and this is the reason for bonking at 32kms. To avoid this, it is very important to fuel on runs longer than an hour. I would typically recommend 0-8gms of carbs/kg of bw every hour. For example, a runner who weights 60kgs should plan to take at least 48gms of carbs. I would also recommend a good electrolyte that contains 6-8% of carbs for runners longer than 45 minutes. It is suggested to avoid simple & refined carbs and stick to complex carbs.

Source: Rice, Fruits, Starchy Vegetables, Millets etc.

2)   Fat - Fat is an alternate source of fuel for running and it is also required for the structural & metabolic functions of the body. It is worthwhile to note that the body cannot shift to fat as fuel once carbs are depleted. This is one of the reasons why most runners train their body for fat adaptation as fuel. The body typically can hold about 40 times that of carbs in the adipose tissues and hence most ultra-runners rely on fat as fuel for longer runs.  Fat is divided to saturated, unsaturated & transfat and I would suggest to avoid eating a lot of saturated & transfat for a healthy living

Source: Avacado, Nuts, Dry Fruits, Vegetable Oils etc.

3 ) Protein  - Proteins are building blocks for the human body and it is essential for recovery & re-building of muscles. I would suggest intake of 0.8-1.2 gms/kg of BW based on the intensity of the workout. Maintaining a proper balanced and healthy diet along with adequate sleep will help in proper recovery.  While we workout, the muscles goes through wear & tear & protein intake aids in quick recovery. Protein is an overhyped phenomenon and commercialized by the supplement industry.  Excess protein is alternatively stored as fat and processing too much protein will also place stress on our kidneys. Unless you lift regularly, protein supplements are NOT required.

Source: Dal, Lentils, Brocolli, Spinach, Beans, Tofu etc.


Micronutrients include vitamins & minerals and it is required for normal functioning of body such as energy production, absorption of nutrients from food, injury prevention and they play the role of a catalyst to aid proper functioning of the body


Phytonutrients are required to improve immunity for runners. The use of phytonutrients differs from individual to individual to a great extent ranging from anti-oxidants to hormone metabolism to anti carcinogenic activities.



This article is purely meant for understanding the science behind nutrition and we would recommend consulting an expert/nutritionist, if you plan to work on your diet.

Aravind Kumar

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Coach Aravind believes in a holistic approach to training combined with nutrition & recovery based on proven research. He is the founder of his coaching initiative Metamorphosis. Aravind has become an accomplished ultra-runner over the last 6 years. He was one of the youngest Indians to complete the Comrades Marathon in 2014. He is also one of the first Indians to finish the grueling Hong Kong Ultra in 2017. He is a finisher of the 100km Run of Kutch where he raised money for charity. He is also the winner of the Bhatti Lakes Ultra 100km (Delhi).