By Rachel Hannah
Health Canada is currently faced with a big challenge in updating Canada’s Food Guide, which has not seen any modifications since 2007. Health Canada has received a lot of scrutiny over the years, with some arguing it has not changed enough since it was first created in 1942. The organization has recently released a mission statement outlining its priorities and “guiding principles.” These discuss a shift towards more plant-based and vegan eating, minimizing processed foods and sugar-sweetened beverages, more knowledge and skills to navigate our complex food environment and consideration of the environmental impact of our food choices.
The new guide should be made public soon, and you can expect to see some major changes coming. In the anticipation of these changes and guiding principles, let’s review some guiding principles on healthy eating and performance for Canadian runners.
It’s important to meet your calorie needs and try to spend as much time training in a state of energy balance. The exception here is when weight loss or a change in body composition is desired. One way to calculate your own estimated calorie needs is to use a predictive equation like the Mifflin St-Jeor, Harris-Benedict or, if you know your lean body mass, the Cunningham equation, which is the best one to use for athletes. If you want a calorie-tracking program to help you figure out a goal and track it, MyFitnessPal is a very useful app. Keeping a food diary will also provide a lot of other useful information such as macronutrient distribution and fibre intake, and allows you to keep a valuable record leading up to races.
Glycogen is the stored form of carbohydrate in the muscle and it’s the main fuel source for high intensity exercise. This is why carbohydrates should be the primary macronutrient consumed in a runner’s diet. Needs should be tailored to the individual athlete, but here are a few general guidelines based on training load and grams per kilogram of body weight:
Light (low intensity/duration): 3–5 g/kg/day
Moderate (~1 h/day): 5–7 g/kg/day
High (an endurance program of ~1–3 h per day of moderate-high intensity exercise): 6–10 g/kg/day
One way to ensure that carbohydrate needs are being met is to make sure that additional carbohydrates are consumed in meals before and after training time and if the intensity and duration increased, so should the carbohydrate intake.
Carbohydrates for competition and training
When running goes over 75 minutes, depletion of carbohydrate stores can cause fatigue and a decline in performance. Strategies should be planned in advance to reduce or delay this in hours or days leading up to the event. Most athletes can normalize muscle glycogen stores within 24 hours of consuming adequate carbohydrates and tapering exercise. Definitely carb load for that big goal marathon or an ultra. This includes meeting the highest targets for carbohydrate intake in the 48 hours leading up to the race (9–12 g/kg/day).
Carbohydrates during an endurance race
For marathons (or longer), aim to take in 60–90 g/hour from multiple transportable carbohydrates like maltodextrin and fructose or glucose and fructose, since the body cannot use more than 60 g/hr from a single carbohydrate source. Practice this well in advance of your race to train the gut to adapt and to minimize gastrointestinal discomfort.
Protein intake targets for both strength and endurance athletes are about 1.2–1.8 g/kg of body weight per day. Most people easily meet their protein needs, but it’s ideal to spread it out evenly at meals and snacks throughout the day. Protein plays a large role in the body’s response to exercise. It is made up of amino acids, which are the building blocks for new and damaged tissue.
Fluid and sodium needs
Fluid needs vary greatly from person to person, but you should aim for a sweat rate of no more than a two per cent of your body mass loss. Aim to drink 1.2–1.5 litres for each kg of weight loss during a run. Most sports drinks have the needed 4–8 per cent carbohydrate content. and required sodium, and you can also add table salt to a post-run meal.
Vitamins/minerals and supplement considerations
Most athletes can meet vitamins and minerals recommendations just by eating a balanced diet. But if you’re trying to lose weight, think about supplementing with individual vitamins and minerals, but be sure to consult a qualified sports nutrition expert. Vitamin D, iron, calcium and magnesium are especially important for runners.
Simplicity is the best way for a runner to eat. Focus on an abundance and variety of fresh fruit and vegetables (fill half your plate), whole grains, oily fish, plant-based protein sources like legumes, nuts, seeds and soy, lean animal proteins and healthy fats like avocados, vegetable oils and nuts or seeds. Athletes receive a lot of conflicting nutrition information, and you should customize your approach based on your needs to maximize both your health and performance. When in doubt, consult a registered dietitian who works with runners. The best nutrition plan is one that provides optimal energy, maintains good health and is enjoyable so you can maintain it for life.
Rachel Hannah is a registered dietitian specializing in weight management and performance nutrition at the Medcan Clinic in Toronto. She’s also one of Canada’s top distance runners.