Fueling long distance ultra-races and training runs over 4hrs is crucial for performance and can make the difference between finishing a race strongly and a DNF. When you have invested so much time in training the last problem you want in your race or challenge is poor attention to your nutrition strategies that could lead to a lot of problems ranging from stomach issues to complete energy depletion.
As an endurance athlete you have a store of glycogen going into a race if you have tapered and eaten the day and morning before an event. So how long does this store last? When do I need to start eating in a race? What foods can my body tolerate? These are some of the questions that have been running through my head when I try to put together a nutrition strategy for a long race.
Carbohydrate (CHO) intake should be the primary focus, through fats and protein are important, more on those later. CHO is used by the body as glucose to produce ATP the energy molecule that is crucial in all aspects of biological work, most importantly during an ultra-marathon for muscle contraction. CHO can be absorbed up to as much as 90g/h in two forms 60g from glucose and 30g from fructose to allow for gastric emptying and absorption of nutrients (1). Intake level over this number is likely to cause GI distress and stomach issues. Another very important note is that this level of CHO intake may be far to high for individuals for a number of reasons including fitness levels, temperature, palate fatigue, gastric emptying, external stress and oxidative capacity (2). The good news is that you can train your body to tolerate high levels of CHO intake during endurance events. This means training taking on nutrition whilst running, fine tuning your strategy for your race. All nutrition products (bars, chews, gels) with the correct glucose to fructose ratio will absorb into the body to be used for energy and using a mixture of fuel sources is advised to prevent palate fatigue. Another important note is drink fuel mixtures, a concentration of 6-8% is advisable as solutions over 10% can slow gastric emptying and cause GI distress. A good starting point is 40-50g/hr building up to the maximum you can tolerate, you can also make calculations based on body weight 1-1.2g per kg per hour.
Protein taken alongside carbohydrate during exhaustive or muscle damaging exercise can minimise muscle damage and preserve net protein balance. This is important in mountain or trail ultras due to the muscle damage elicited by eccentric muscle contractions due to the extreme vertical challenges the athlete faces (6). Protein should be taken in small quantities 0.25g/kg/hr along side CHO 1-1.2 g/kg/hr. Fuel forms can be specific sports products or from real food such as a peanut butter and jam sandwich.
Fat is used as a fuel source for intensities below 70% VO2 max an intensity that most athletes would complete an ultra-marathon at. Fat is converted to energy using a process called beta oxidation which yields a high net produce of ATP, the molecule used for muscle contraction. Individuals have a highly abundant storage of fatty acids in the body that can ben used for fuelling exercise, even the leanest of athletes. Fat intake during exercise must be practiced and may not be tolerable for many, however if you can train you body to take in a small amount of fat during endurance training and use this in races you can open up a nutritionally dense energy source that will fuel low intensity exercise and also keep you feeling satiated. Another important note is per gram fat will give you the most energy, so if you have to carry all your nutrition/food including fat sources will help to keep the weight down.
In a practical sense what do macronutrients look like in terms of nutrition product and real food:
Table 1. (3)
Our favourite sports nutrition is Mountain Fuel, we use both the Ultra Chia and Sports Jellies. Below is an example of the nutritional information from the Ultra Chia Gels and Sports Jellies. (4) (5)
Raspberry Ultra Chia Gel
Ingredients Raspberry juice from concentrate, water, Coconut sugar, water, Ground Chia seeds, Lemon juice, Beetroot juice concentrate, Sea Salt, Natural flavour, Preservative (Potassium sorbate)
Nutritional info – per 100g / per 60g sachet
Energy – 159kcals / 95kcals – 665kJ / 399kJ
Protein – 3g / 1.8g
Fat – 0.8g / 0.5g
Carbohydrate – 33.1g / 20g
Of which sugars – 29.9g / 17.9g
Fibre – 1.74g
Sodium – 24mg / 14mg
Potassium – 60mg / 36mg
Nutrition during training and competitions can seem like a complicated and daunting task to master but is crucial for performance in long distance ultra’s over 4hrs. Start simple and train your body to take in nutrition on the move, this means practicing and developing your fueling strategy on a weekly basis. Ultimately if you can build up to 1-1.2g/kg/hr CHO, 0.25g/kg/hr protein and a small amount of fat you will optimise your performance. Remember to mix your CHO fuel sources and use different forms be it bars, gels, chews, drink mix or real food. Do your research, even if this means just looking at the nutritional information on the back of your gels and bars. Take your fueling as seriously as training and equipment choices and your body can take you a long way.