Food and nutrition are massive components of sports performance for any active person. Whether you are a competitive level athlete or you are committed to a sport or activity at a more casual level, how you eat makes a difference. Although athletes and active people do not necessarily need to eat drastically differently than the normal population, there are several fundamental nutritional topics that they must take into consideration.
My goal with today’s posting is to explore each of these topics and to put you in a better position to succeed from a nutritional and performance perspective. Eating smarter can go a long way to improve your health and physical performance, regardless of the sport/activity you do and the level of competition you do it at.
The scientific content found in today’s blog posting is sourced from my review of two highly reputable reports on nutrition in sport. The first, provided by the International Olympic Commitee, and the second, provided by the joint efforts of the Dietitians of Canada, The American Dietetic Association and the American College of Sports Medicine. All of the credit for the nutrition science discussed in today’s blog goes to the researchers involved in contributing to and synthesizing those reports. I urge anyone looking for more in-depth sports nutrition information to have a closer look at the great work they have done.
The Fundamental Topics in Sports Nutrition
1. Carbohydrates: Carbohydrates are a macronutrient most abundantly found in foods such as fruits, vegetables and grains. Adequate carbohydrate intake is absolutely critical to ensuring peak athletic performance. Carbohydrates are your body’s primary fuel source. They circulate in your blood, in the form of glucose, and are also stored in your muscles in the form of glycogen. Adequate carbohydrate consumption will help ensure both your circulating and storage levels of carbohydrate remain optimal. This will help ensure you perform at your highest capacity by increasing the time required for you to run out of fuel ( also known as fatigue).
For the reasons outlined above, low carbohydrate diets are not recommended for athletes or active people. A regularly training/competing athlete should aim to consume between 6-10 grams of carbohydrate per kg of body weight per day. If you are not a competitive athlete, but train or play at least an hour a day, you can aim for closer to 5-7 grams of carbohydrate per kg body weight per day. You might lower that amount down to 3-5 grams of carbohydrate per kg on rest days. Since carbohydrate requirements are directly related to activity levels, the exact amount you need will vary on how much energy you expend on a given day. One of the biggest differences in nutrition requirements between an average person and an active person is the increased need for carbohydrates to account for energy expenditure through sport or training.
(Your weight in pounds (lb) divided by 2.2 will provide you your weight in kilograms (kg))
On any day where exercise endeavours of greater than 60 minutes are anticipated, it becomes important to use the “pre-game meal” as an opportunity to consume adequate carbohydrates. You will want to aim for a meal containing at least 1 gram of carbohydrate per kilogram body weight. Depending on the athletes comfort levels and preferences, the pre-game meal can be consumed between 1-4 hours before the competition. Consuming adequate carbohydrates before strenuous activity, especially for activities of longer duration, will aid your performance. If you want to know how much carbohydrate is contained in a specific food you are eating, try using the Canadian Nutrient File Food Database.
Sample Pre-Game Carbohydrate Calculation: Jim is a competitive soccer player and weighs 150 lbs. He wants to calculate his weight in kilograms so he divides 110 by 2.2 and determines he weighs 68 kg. Jim has a soccer game in a few hours and knows that, before the game, he should consume at least 1 gram of carbohydrate for every kg he weighs, which ends up being about 68 grams of carbohydrate. Jim likes to eat spaghetti before games so he types in “cooked spaghetti” into the Canadian Nutrient File Food Database and determines that 1.5 cups of cooked spaghetti ( 375 ml) contains about 68 grams of carbohydrate. Jim now knows that, before games, he should be consuming at least that amount of spaghetthi to ensure he is getting enough carbohydrates to fuel his performance on the soccer field. Please refer to sections 8 & 11 for further details on pre-game nutrition preparation.
Our friend Jim may also benefit from the knowledge that prior to days where activity greater than 90 minutes is expected ( multiple games, tournament days, championship games), it may benefit him to consume more carbohydrates than usual. This process, known as carbo-loading, involves eating up to 9-12 grams of carbohydrate per kilogram body weight per day on the day before the event. Carbo-loading may improve energy stores and sport performance on days before a big sporting event. Eating extra fruits, grains and starchy vegetables should help you achieve this recommendation.
2. Fat: Adequate fat consumption is an important component of a healthy, balanced diet. Fat is our body’s secondary energy source during physical activity. Most people should aim for between 20-35% of daily energy intake to come from fat. Do not be persuaded by trendy diets that may include higher fat content and extremely low carbohydrate intake. Eating in this way will not benefit your sports performance and it is not a recommended style of eating for active people. At the same time, it is not recommended to restrict your fat intake either. Healthy sources of fat such as nuts, fish, vegetable oils and avocados are rich in important nutrients and should not be neglected. A balanced eating style that does not restrict or neglect food groups should be sufficient to ensure you consume the optimal proportion of calories from fat.
3. Sports drinks: Just like race car drivers need pit-stops to refuel during long races, athletes and active people may also benefit from refuelling their carbohydrate stores during longer sporting or training events. In fact, in athletic endeavours lasting greater than 60 minutes, the natural use and depletion of your carbohydrate stores may contribute to fatigue and a decrease in performance. This is great news for all the Gatorade and sport drink fans out there because it means that sport drinks may have a valuable and justifiable place in your sporting life. To keep things simple, sports drinks may improve performance if the following conditions are met:
- You are exercising at an intense level for a period of time greater than 60 minutes
- You perceive or expect to perceive yourself as being fatigued in that period of time
Under these conditions, sports drinks have the ability to help you fend off fatigue and maintain performance levels. It is suggested you consume between 30-60 grams of carbohydrate per hour under such conditions, this amounts to between 500 ml and a 1 litre of commonly available sports drinks. Sports drinks have the dual ability to rehydrate (making up for water and salt losses) and refuel ( making up for carbohydrate usage) you during strenuous sporting or training endeavours. They may be particularly important to your performance on days where you did not consume adequate carbohydrates before the event.
As an example, a full length soccer game generally runs 90+ minutes and would be an ideal scenario for supplemental carbohydrate consumption. It is important to recognize that different people may respond differently to carbohydrates consumed during competition, so stick to what works for you. Trying sports drinks during longer practice or training days will help you determine how you will respond to them in a game scenario. If you are using home-made sports drinks, it is advisable to use a mix of sugars ( ie: both glucose and fructose, rather than just one or the other) as this will enhance your body’s ability to absorb and utilize them.
4. Protein: Protein has been a hot topic in sports and general nutrition for a long time. Achievin adequacy in your protein intake is important to maintain general health, optimize muscle growth/repair and promote post-training recovery. Protein recommendations for the general population are 0.8 grams per kilogram of bodyweight, however for endurance and strength athletes this value increases to between 1.2-1.7 grams per kilogram, with strength athletes on the higher end of the spectrum.
Please note that you do not require expensive protein supplements to reach these recommendations. The majority of people reading this post should have little problem meeting these requirements through a balanced diet. There is no evidence to suggest that the use of protein supplements will improve your muscle growth any better than protein from food when calorie intake is equal. Protein is not a magical muscle builder, in order to make the most of your intake you must ensure you are consuming a sufficient amount of total calories.
When it comes to post-training recovery, whether you are an elite or recreational athlete, adequate protein consumption has an important role to play. Consuming about 20-25 grams of protein, the amount in about 3-large eggs, with a post-training meal will help promote muscle recovery. Keep in mind that protein consumption in excess of this amount will most likely be used as an energy source for your body, rather than for muscle recovery (ie: you might as well just have more carbohydrates instead). Ideal animal protein sources include dairy, meat, eggs, fish or poultry whereas vegetarian athletes can turn to beans and tofu or other soy products. Remember to also include fluid and carbohydrates in your post-training meals.
5. Iron: Anyone who regularly engages in intense physical activity may have increased iron requirements. This may be especially true for female athletes, adolescents, vegetarians, long distance runners and anyone who restricts their intake of particular food groups without adequate planning. If you fall into one of these categories you should ensure your health care practitioner regularly monitors your iron status. To learn more about iron requirements, iron-rich foods and iron absorption please have a look at the following Eat Right Ontario Iron Resource.
6. Other Micronutrients: Just like anyone else, athletes and active people are at risk of consuming a variety of nutrients at inadequate levels. Balancing training and competition commitments with everyday life, budgeting, work and school may leave less time and resources for food preparation. Pressures to maintain a certain body weight or image may also contribute to unsafe food practices. If you often engage in extreme weight loss behaviours , restrict your calories or restrict certain food groups, you will be at even higher risker of micronutrient deficiency.
Vitamins and minerals that tend to be issues for athletes may include calcium, vitamin D, zinc, magnesium, vitamin C, vitamin E, the B vitamins and selenium. Clearly this is an extensive list and the vitamins/minerals identified here are found in a wide array of foods. The quickest and best advice I can offer is you is to take a look at the Canadian Food Guide and ensure you are eating a great diversity of foods from each food group. Diversifying your food intake is a great way to ensure balance in your micronutrient consumption. If you are a particularly high level athlete and you fear that your diet lacks adequacy or balance, you may consider having it reviewed more closely by a health professional as dietary shortcomings could potentially be harming your performance and your health.
7. Calories/Body Weight & Composition ( Body fat%)/Dieting: As I mentioned earlier, the increased calorie requirements of active people is what most distinguishes their dietary reqirements from the general public. Athletes and highly active people require more calories, particularly in the form of carbohydrates, to make up for energy use during exercise. It is most reasonable for athletes to seek extra calories from carbohydrate-based food groups such as grains, fruits and vegetables. Athletes will certainly need to eat more foods from these groups than non-active individuals.
Issues may arise when athletes are dissatisfied with their current body weight or body composition. Depending on a great number of factors, altering your body weight or body composition could potentially improve your performance. This is highly dependent on the sport or activity that you are engaged in. For example, in sports where speed is important a lighter, leaner composition may be advantageous. Regardless of your current status, it is very important that you do not engage in drastic weight loss behaviours. Slight reductions to your caloric intake over time is the safest and best way to alter your body composition. Please keep in mind Altering your body composition takes time and severe restrictions to your calorie intake, especially during competition or training season, is dangerous:
You put yourself at risk of micronutrient deficiency which could have consequences on both your short and long-term health and wellbeing.
You put yourself at risk of caloric inadequacy, meaning you are not consuming enough energy to fuel your body for your athletic endeavours and risk severe detriment to your performance and physical progress.
If you are satisfied with the way you perform in your current state, you should not feel the need to make drastic changes. As training intensity increases, it is generally wise to ensure food consumption follows suit to ensure you are adequately fueled.
A special note for any parents or coaches out there, it is never recommended to urge adolescents to diet as this could be detrimental to their physical and mental development, as well as their performance.
8. Hydration: Hydration is perhaps the single most important topic in sports nutrition. Aside from an increased calorie requirement, an increased fluid requirement is the other nutritional factor that distinguishes athletes from the general public. Athletes and active people need to consume extra fluids before, during and after exercise to account for fluid losses through sweat and to maintain adequate hydration status. As a general rule, it is best to make a concious effort to consume water regularly throughout the day while paying special attention to your hydration status before games or events.
It is recommended to consume between 5-7 ml of water per kg of body weight at least 4 hours before sporting or training events. This will allow your body to be in optimal performing condition. Once activity begins, fluid loss through sweat becomes important, particularly in endeavours of greater than an hour in duration where sweat losses may be higher. Sports drinks, which contain both carbohydrates and sodium, are an ideal hydration aid in such instances whereas water may be more suitable in endeavours an hour or under.
The “Salty Sweater” Test: As described by the International Olympic Committee, the salty sweater test entails wearing a black T-shirt during training and looking for white powder/salt stains under the armpits and chest area at the end of the session. If you are a salty sweater, this may contribute to muscle cramping and decreased performance during physical activity. In such cases, consuming sports drinks with high sodium levels ( rather than water) may be an even more important strategy to aid in your performance.
There is so much more to hydration and hydration science than I can do justice to in the time and space that I have alotted for this blog posting. I urge anyone interested in learning more to review the two reports that I referenced at the beginning of the article.
9. Supplements: Most sport and athletic supplements available on the market do not do what they claim to do. If it sounds too good to be true, it probably is. However, one of the most widely used and widely researched supplements available, creatine, has been shown to be useful for high intensity/short- burst activities such as sprinting and weight lifting. Creatine has not been shown to improve performance of endurance athletes.
In terms of vitamin and mineral supplements, I only ever recommend their use if you are certain that you are not adequately consuming a particular vitamin/mineral and, for whatever the reason may be, will have trouble adapting your diet to account for that. The use of vitamin/mineral supplements will not improve your performance if you are already consuming an adequate diet and should never be an excuse for unbalanced dietary choices.
10. Caffeine: I have good news for coffee lovers. Caffeine in the amounts of 1-3 milligram per kilogram of bodyweight , prior to exercise, have been shown to aid in sports performance. What does this mean for most adults? Assuming you are properly fed and hydrated, a cup of coffee with your pre-game meal may actually help. You might now be thinking that if caffeine is good, and if carbohydrates are good, then energy drinks (not to be confused with sport drinks such as Gatorade) should be great.
You would be wrong in thinking this. Energy drinks are not recommended for hydration before , during or after exercise. Some varieties may contain a very large amount of sugar (double that in sports drinks) and the carbonation may contribute to gastrointestinal distress in some people. They also contain a variety of other compounds that may pose health risks when combined with alcohol or other stimulants. My personal advice, and the advice of sport nutrition professionals, is to avoid these products.
11. The Pre-Game Meal: Sections 1 and 8 cover the carbohydrate and fluid recommendations important for pre-game meals, but I wanted to briefly revisit the topic here as well as it is an important one for most people. When it comes to the pre-game meal, it is important to know yourself and know what has worked well for you in the past. Experiment with different meal sizes and digestion times ( 1-4 hours before the gmae) to help you find the right fit that keeps you feeling satisfied and energetic without a heavy or disruptive feeling in your stomach. The general guidance for pre-game meals, as per professional nutrition researchers, is to include plenty of water and carbohydrate , moderate protein and keep it low in fat and fibre, as these take longer to digest. Having a meal low in fibre is generally the opposite of what I would normally recommend to most people, but keep in mind you are prepararing for very specific circumstances. Here are some practical tips to help you achieve these recommendations:
i. Just this once, go easy on the vegetables as they are very high in fibre.
ii. Hold off on using excessive amounts of oils or fatty foods like sausages.
iii. Opt for white pasta rather than whole wheat to lower the fibre content.
iv. Try using dairy or lean meats, such as chicken breast, for some protein.
v. Pre-game, fruit juice may be a better alternative to a whole fruit.
12. Vegetarian Athletes: Just like other vegeterians, vegetarian athletes face unique and important nutritional challenges which can usually be overcome with adequate dietary planning and preparation. Due to the restriction of certain food groups, vegetarian athletes may be at greater risk of certain energy and micronutrient deficiencies. Here are some points to keep in mind if you or someone you know is a vegetarian athlete:
i. You may be at even greater risk of iron deficiency than a non-vegetarian athlete. Have your iron status monitored by a health professional.
ii. If consuming eggs and dairy is acceptable to you, take advantage of that opportunity to consume high quality proteins from those foods.
iii. Incorporate high quality plant sources of protein such as tofu and pulses ( beans, chickpeas, lentils). Vegetarian athletes should aim for 1.3 to 1.8 grams of protein per kilogram bodyweight because plant proteins may not be as well absorbed.
iv. Consume calorie dense plant-products such as nuts, seeds, avocados and vegetable oils to ensure adequate fat and calorie intake in the absence of animal products.
v. Be wary of calcium, vitamin D, vitamin, B-12, Riboflavin and Zinc. Have a look at my article on plant-based diets for further guidance on how to ensure adequacy in those micronutrient groups.
vi. The nature of vegetarian diets may lend to them being lower in calories. It is important to ensure caloric adequacy if you are on a vegetarian diet. If you find yourself unintentionally losing weight, take that was a warning sign. Certain people, particularly women, tend to gravitate towards vegetarian diets for this reason. If you are a parent or a coach of a young athlete, be wary of such behaviours and observe that steps are taken to ensure adequacy in caloric intake and bodyweight.
Thus concludes my overview of all things sports nutrition. As with anything in life, small details can make a big difference when it comes to sports nutrition and your performance. My hope is that you take away at least a few points here today and they benefit your performance, regardless of the sporting or athletic endeavour you are involved in. I do believe the guidance provided here , and even more so in the reports referenced at the beginning of the article, will be of great value to you whether you are an athlete, parent or coach. As always, I wish you the best of luck in your food, nutrition and sporting endeavours.
Until next time, Eat Up!
Andy De Santis RD MPH