Eat for endurance – marathon training and endurance walking (Part 2)

So last month we looked at some of the basics for eating to run, and how to get a balanced source of energy for exercise. This month our focus shifts to eating for endurance in support of our very own Kathy who is busy training for Boston 2018. For anyone out there who has completed a marathon or is currently in training for an endurance event (defined as <6 hours), one of the tricky things to master is how to eat and have enough energy to sustain you for the whole 26.2 miles / 42km. What if you run out of fuel?


Much depends on your level of fitness and experience in endurance events. Professional athletes will have built their routine around hours and hours of training and race experiences to find what works best for them. And the same goes for the rest of us. As you train regularly and begin to compete you will slowly discover your body’s individual physiological needs.

Training and nutrition are two of the most important aspects of preparing for endurance events and this includes nutrition (types of foods to eat), hydration (liquid and metabolite balance and recovery (foods to aid repair).

Here are a few tips to help get started:


Energy in = Energy out*

A good aim for endurance training is to eat a sufficient number of calories, equal or close to those expended during the event. Food provides fuel which is key to endurance and it is important to stock up energy reserves. Calorie intake throughout training is important preparation, as important as prior to the race.

*Please note this can vary with individual metabolism and is not an exact equation, simply an indication that the body will require sufficient energy for physical endurance events.

Source of foods

Your body can use carbohydrate, proteins and fats as energy but it may use them at different times based on oxygen requirements during endurance events.

Standard marathon pace, when oxygen requirements are high, has been shown to rely on c.95% carbohydrate foods for energy. We often hear of carb-loading before events as this is intended to optimise the body’s stores of glucose. Carbohydrate foods include all grains, pasta, rice, quinoa and also nutrient-rich starchy vegetables such as sweet potato, carrot, parsnip, swedes. It is important to include a wide range of carbohydrate in the diet, especially vegetables which also supply nutrients which can help aid recovery after exercise (Burke, LM., et al., 2004).

Lower intensity endurance walking, when oxygen requirements are more easily achieved, has been shown to use fat as the primary source of energy. It is recommended that athletes aim for 30-35% fat intake as per government guidelines (Burke, LM., et al., 2004). Healthful polyunsaturated fats can be found in oily fish, avocado, nuts and seeds, coconuts, vegetable oils (not heated but used as a dressing).


Hydration is essential for endurance activities when the body will have an increased loss of fluids through sweat. As little as a 2% reduction in body mass due to dehydration can impact performance, energy levels, your ability to manage body temperature, as well as put extra strain on your cardiovascular system (Williamson, E. 2016). So how can we avoid becoming dehydrated?


Our body has its own built in mechanism to tell us what it needs and the first signs of feeling thirsty are generally a good indicator that your body needs fluids. Drink little and often. Flooding the body with fluid can have adverse effects just as drinking too little can be harmful. Fluid intake is another important consideration for any training regime and gives you the chance to get to understand your personal requirements.


water glass
water glass







Join us next month for the next part of our eat to run series where we’ll be looking at nutritional tips to help with Performance on race day, and recovery.


  1. Burke, LM., et al., 2004. Carbohydrates and fat for training and recovery. J Sports Sci. 2004 Jan;22(1):15-30.
  2. Williamson, E., 2016. Nutritional implications for ultra-endurance walking and running events. Extreme Physiology & Medicine, [online] 5(1), p.13.