Endurance Power from Potatoes
If you are an endurance athlete who is fearful of “hitting a wall” during exercise listen up: proper fuelling before and during your marathon can make the difference between agony and ecstasy! If you plan to compete for longer than 70-90 minutes, research indicates that performance is improved through maximal glycogen storage in the muscles prior to a race. Performance is also improved when muscles are sufficiently fuelled with glucose during the exercise session. Poorly fuelled muscles both pre and during racing is associated with unnecessary fatigue. The more glycogen and availability of glucose to the exercising muscle, the better the endurance capacity.
Glycogen is a chain of glucose molecules that is the body’s most effective and immediate energy source. It is stored primarily in the liver and in the muscles. Endurance sporting events, such as marathons or cycle races, place large demands on muscle glycogen stores. Your body can only store enough glycogen (in your muscles and liver) to sustain between 70-90 minutes of exercise. Thereafter the stores are depleted. If stores are depleted, the muscles cannot perform at their optimum and that is when fatigue sets in or you feel that you have hit the dreaded “wall”. Research from way back in 1997 is still relevant today, where researchers found that super compensated or “carbo-loaded” muscle glycogen levels can improve performance by 2–3% in events lasting more than 90 min.5
HOW MUCH IS ENOUGH?
The amount of dietary carbohydrate required depends on the duration and intensity of the exercise programme and is highly individualised from athlete to athlete. In research studies, intakes of carbohydrate between 10-12 g/kg body weight/ of carbohydrate per kg of body weight per day for 36-48 hours before competition have been shown to increase muscle glycogen concentrations.8 Intakes higher than this may not offer additional benefit to prolonged endurance performance, especially if a carbohydrate rich pre-competition meal is eaten and muscles are well felled with carbohydrates during the exercise.
HOW CAN I CARBO-LOAD?
Increase intake of all food in a balanced manner over 1-2 days prior to the race. Focus specifically however, on nutrient dense carbohydrates such as whole grains, fruit and legumes with the shortfall being made up of refined carbohydrates and sugars around training sessions. Each meal should consist of on average 60-90g of the above mentioned, good quality carbohydrates – approximately double to triple one’s average carbohydrate intake.
Top-tip: Don’t alter your diet drastically ahead of a race. Stick with familiar foods that you know are well tolerated and rather focus on increasing the volume. Golden rule applies: Don’t try anything new on race day!
For example, the requirements for a male who weighs 78 kg would be 780 – 936g CHO per day for the 1-2 days leading up to a race. This would be as follows:
The table below shows how nutrient needs increase during pregnancy…
|6x Starch servings i.e. 3 slices Low GI seed toast spread with Avo or Peanut Butter = 90g CHO||3x Fruit Servings i.e. Fruit Smoothie or 3 Tbs. Raisins or 15 strips Dried Mango = 45g CHO||2x Starch servings i.e. 1 ½ cups Quinoa or Brown Rice or 9 Baby Potatoes = 30g CHO||3x Fruit or Starch Servings i.e. 9 wholewheat crackers or 4 ½ cups cooked Popcorn or 4 Tbs. Goji Berries with 250ml 100% Fresh Fruit Juice = 45g CHO||3x Starch Servings i.e. 2 large Baked Potatoes (270g) or 1 ½ cups cooked Pasta = 45g CHO||255g CHO|
Additional throughout the day: 525g CHO → 100g bag of Sweets (91g CHO) + 500ml Freshly Squeezed Fruit & Vegetable Juice (60g) + 2x 45g Energy Bars (50g) + 200g Bag of Dried Fruit (97g) + 240g Isotonic Sports drink powder in 2 litres of water (228g CHO)
CHOOSE CARBOHYDRATES WISELY
As you will see from the above, it is a lot of food! Concentrated sources of carbohydrates such as potatoes will help to ensure that the volume of food needed isn’t so enormous! In addition, recommendations suggest to decrease the fibre content in the diet the day before and on the day of the race to reduce potential stomach distress during the race. Potatoes are very effective for this as you can increase or decrease the fibre content depending on the cooking preparation and method. The best way to cook and eat a potato for optimal health is baked/boiled/steamed with skin still intact. However, if you need to reduce the fibre content specifically for a race then you can prepare and eat it without the skin. The recipes below give two alternate options of how to prepare potatoes with varying fibre contents, before a race.
HERBED MASHED POTATO (LOW FIBRE OPTION) – SERVES 4
4 large Potatoes
½ cup Low Fat Milk or Buttermilk
Handful of Fresh Parsley & Oregano
Pinch of Salt & Ground Black Pepper
Peel the potatoes before adding them to a large pot with enough water to cover. Cover and bring to a boil over high heat. Reduce the heat to medium low and simmer until the potatoes are tender when pierced (25 to 30 minutes). Cut the potatoes into chunks and add fresh chopped parsley and oregano together with ½ cup buttermilk or Low Fat Milk. Using a potato masher, mash until mostly smooth and sprinkle with seasoning.
Nutritional Information per serving: 694kJ Energy; 4.1g Protein; 1.1g Fat; 31.4g Carbohydrates; 1.8g Fibre; 524mg Sodium
SMASHED ROSEMARY ROASTED POTATOES (HIGHER FIBRE CONTENT) – SERVES 8
1.5 kg bag of Baby Potatoes
40ml Olive Oil
Handful Rosemary Sprigs
Ground Black Pepper
Himalayan Pink Rock Salt
Wash baby potatoes whilst keeping skin intact. Par boil potatoes in boiled water for 10-15 minutes. Space potatoes on a roast pan 4 cm apart from each other. Smash/squash potatoes using a fork. Drizzle with Olive oil, fresh rosemary sprigs & season. Roast in the oven for 30-40 minutes until golden and crispy. Serve as a side to any roast meal.
Nutritional Information per serving: 794kJ Energy; 2.8g Protein; 5.2g Fat; 29.8g Carbohydrates; 2.8g Fibre; 246.6mg Sodium
THE POWER OF POTATOES
Potatoes are full of key nutrients that can help boost running power. Sports scientists from the Sports Science Institute of South Africa (SSISA) have found that potatoes are an ideal source of carbohydrates prior to endurance races and that carbo-loading with potatoes can influence peak performance3. Beyond this, potatoes are not only perfect as part of your carbo-loading regime they are well suited as a fuel option for during the event itself. One medium sized potato (150g), cooked with skin, is high in carbohydrates and naturally free of fat. High fat contents consumed during exercise have been shown to cause stomach upset and discomfort in some due to the delayed gastric emptying that follows high fat meals.8 Potatoes are high in the mineral chromium and have a potassium content that is higher even than a banana! Potassium is an electrolyte that is very important to balance hydration status and reduce risk of cramping. Another example of how the potato is the perfect fit for endurance exercise!
QUICK TIPS: WHY CARBO-LOAD OR REFUEL WITH POTATOES?
Potatoes have high palatability at all stages of exercise.
Sweet foods can become unpalatable in longer duration activity where taste disgeusia (distortion of tastes) sets in and an aversion to sweet things such as gu’s, gels and drinks can be very common.
Potatoes are an easy way to get sodium in. Potatoes are delicious with a sprinkle of salt and this is important for provide adequate sodium for optimal electrolyte balance to avoid fatigue, cramping and dehydration during endurance races.
Potatoes are easy to boil and prepare the night before and don’t need to be refrigerated or won’t get ruined during long endurance events. Baby potatoes especially are compact and easy to transport for longer stage races
1. Wilson PB, Ingraham SJ, Lundstrom C & Rhodes G. Dietary tendencies as predictors of marathon time in novice marathoners. Int J Sport Nutr Exercise Metab. October 2012.
2. Atkinson G, Taylor CE, Morgan N, Ormond LR & Wallis GA. Pre-Race dietary carbohydrate intake can independently influence sub-elite marathon running performance. Int J Sports Med. 2011. Aug;32(8):611-7.
3. Laurie HG, Rodger I, Wilson R et al. The Effects of Carbohydrate Loading on Muscle Glycogen Content and Cycling Performance. Int J Sports Nutr. 1995 (5): 25-36.
4. Baar K. (2013) New ideas about nutrition and the adaptation to endurance training. Sports Science Exchange. Vol. 26, No. 115, 1-5.
5. Asker E. Jeukendrup (2011): Nutrition for endurance sports: Marathon, triathlon, and road cycling, Journal of Sports Sciences, 29:sup1, S91-S99.
6. Stellingwerff, T., and Cox, G.R. 2014. Systematic review: Carbohydrate supplementation on exercise performance or capacity of varying durations. Appl. Physiol. Nutr. Metab. 39(9): 998–1011.
7. Burke, L. M., Hawley, J. A., Wong, S. H. S., & Jeukendrup, A. (2011). Carbohydrates for training and competition. Journal of Sports Sciences.
8. Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine (2016) Nutrition and Athletic Performance. J Acad Nutr Diet. 2016;116:501-528.