Nutrition Guide for Athletes

Written by: Marwah Saeed, BSc (Hons), MBBS

Updated: May 23rd, 2023

Sports nutrition and nutritional strategies have evolved over the years and often follow a “one size fits all” kind of approach. However, research suggests that a tailored approach to individual athlete’s needs, and specific sports is more optimal. Let’s get into it!

Why is Nutrition Important in Sport?

Nutrition is a critical aspect of an athlete’s life. It can mean the difference between peak performance and success and bodily injuries and fatigue. On a fundamental level, nutrition is a source of energy. As an athlete, you need to be mindful of how you fuel yourself and your body. Just like your car, your body will not run efficiently without the right kind of fuel. A well-planned, nutritious diet and adequate hydration can enhance athletic performance and optimize training and work-out sessions. Nutrition plans should be tailored to the individual athlete, and consider their specific sport, goals, food preferences and practical challenges (Beck et al., 2015). During intense physical activity, the blood circulation in the intestinal wall is reduced, because the blood must go first to the muscles subjected to the effort. It is then less oxygenated, which causes damage to its cells. It would therefore become more fragile and permeable to pathogenic microorganisms. The cramps, nausea, and diarrhea that endurance and ultra-endurance athletes sometimes experience are partly explained by this phenomenon (Stéphanie Coté, Dietitian).

How does nutrition affect sports performance?

The choice of what to eat, how much to eat and when to eat (before, during or after training) can impact performance, training, and recovery. Nutrients such as carbohydrates maintain blood glucose levels, fuel activity, and replenish energy stores while proteins aid in muscle growth, recovery, and repair muscle damage (Alexander, 2020). Hydration is also critical in optimizing fluid levels, replenishing electrolytes, and preventing dehydration (Callahan, 2020). Regardless of whether you are an Olympic athlete or just someone who enjoys working out at the gym, you can use appropriate nutrition and exercise to enhance your personal health and overall well-being.

Dietary and nutritional needs of athletes – do they differ from regular nutrition?

The short answer is yes.

Athletes have different nutritional needs compared to the general public. Not only do they require more calories to compete at their optimum level, but they also require greater amounts of macronutrients to maintain strength, endurance, and peak recovery (Streit, 2021).

Macronutrients, commonly dubbed “macros”, are the three big nutrients derived from food i.e., carbohydrates, fats and proteins. They are used in large amounts and are essential for growth, development, and function. All three macronutrients are involved in energy production, in addition to other key roles. Carbohydrates are the body’s primary sources of energy; proteins are considered the “building-blocks”, contributing to the structure of all kinds of tissues from skin and nails to muscles and bones; and fats help insulate and protect organs and assist in the absorption of vital nutrients (Alexander, 2020).

You can find a breakdown of the recommended macronutrient amounts for different age groups on the Health Canada page. The following is the macronutrient breakdown for individuals aged 19 and over:

45-65 percent carbohydrates
10-35 percent protein
20-35 percent fat

This breakdown is a recommendation and may not be appropriate for everyone. Tweak it to suit your age, activity level, specific health needs, medical conditions, and health goals (Streit, 2021; Health Canada, 2022).

Micronutrients are vitamins and minerals which are derived largely from your diet. While they are needed in smaller amounts than macronutrients, they play a vital role in maintaining optimal health, preventing disease, and ensuring proper body functioning. Examples of some micronutrients include vitamins A, B, C, D, E and minerals such as iron, calcium, magnesium etc. (Micronutrient Facts, 2022).

Nutritional requirements also vary based on the type of sports athletes engage in (Beck et al., 2015). For example, strength athletes such as powerlifters have higher protein requirements to develop lean muscle mass unlike endurance athletes (marathon runners and cyclists) who require greater amounts of carbohydrates to fuel themselves for hours of activity (Macronutrient Needs of Endurance and Power Athletes, 2019). A more comprehensive and thorough comparison of various sports is beyond the scope of this article.

What and when to eat when working out

Whether you are an amateur or professional athlete, or somebody who casually enjoys an active lifestyle, considering the following will help promote your overall health and well-being.

Energy requirements for Athletes

The recommended daily caloric intake is 2000 calories a day for the average woman and 2500 calories per day for the average man. It is important to note that these numbers serve as a guide and the amount of energy you need will vary depending on your gender, height, weight, activity level, and age. Additionally, caloric intake is not just about quantity but quality as well because the foods you eat affect your body in different ways (Osilla, 2022).

Micro and macronutrient requirements

Athletes require a well-balanced, nutrient-rich diet with sufficient carbohydrates, proteins, healthy fats, vitamins, and minerals. These nutrients are the foundation of general health and can help boost peak performance and recovery.

Meal and snack timings

It is important to eat the “right foods” at the “right time”. Fueling and hydrating your body before, during and after workout not only affects training and performance but general comfort as well. That said, the timing and amount of food tolerated has been found to vary among individuals. Some people report digestive struggles, such as nausea and cramping, if they consume foods too close to the start of training while others rely on it to ensure adequate blood sugar levels and top up body stores. Additionally, prolonged gaps between meals and snacks can lead to increased fatigue and stress on one’s body. Furthermore, meals rich in fats, can lead to a sense of “heaviness” and sluggishness (Richards, 2021).

Hydration

The human body is comprised of approximately 45-75% water (Jéquier & Constant, 2010). During a workout, you quickly lose fluid when you sweat; this fluid is a combination of water and electrolytes which if left unreplenished may cause dehydration. Water is the best way to rehydrate. A general rule of thumb is to exercise when adequately hydrated and to drink every 15 to 20 minutes during a workout (Callahan, 2020).

The bottom-line is: Speak to your coach, trainer, dietitian, or doctor. Find a nutritional strategy that works for you. Pack healthy snacks and plan ahead.

What are the “right foods” for athletes?

Good nutrition is flexible. And it is okay to tailor it to your personal preferences, health needs and lifestyle provided you have adequate nutrition and fluid through your work-out sessions. Most athletes fuel up with healthy carbohydrates 1-2 hours before a training session while avoiding fats and proteins because they are slower to digest.

Depending on the gap between your last meal and workout sessions (and the presence of distracting hunger pangs) you may want to consider having a small snack such as low-fat yogurt, raisins, or a banana. After working out, eat a meal with proteins and carbohydrates to help your muscles recover and replenish your energy stores (Food as Fuel Before, During and After Workouts, 2023). Here are some foods that you can consider:

Carbohydrates: whole grain breads, high fibre cereals, quinoa, brown rice, starchy vegetables (yams, sweet potatoes), oatmeal, fruits
Proteins: whole eggs, Greek yogurt, legumes, lean red meats, poultry
Healthy fats: hummus, avocado, peanut butter, nuts and seeds (NutriProCan, 2020)
Dietary fibre, good fats and the antioxidants they contain promote the production of short-chain fatty acids (SCFAs) which help in various ways to protect the intestinal wall and prevent inflammation (Stéphanie Coté, Dietitian)

What not to eat before exercise

Avoid foods that are difficult to digest such as those rich in fibre or fat. Examples include dairy, beans, cruciferous vegetables (broccoli, cabbage), etc. These foods tend to remain in the stomach longer, diverting oxygen-rich blood from muscles to the stomach to aid in digestion. Not only can they cause abdominal bloating and gassiness, they can also make you feel sluggish and tired. Other foods to avoid are the so-called “empty calories” which lack nutritional value including pop, alcohol, burgers, fries, candies, cakes, donuts, etc. (Worst Things to Eat or Drink Before a Workout, n.d.).

Nutritional Supplements – Are they worth taking?

Frankly, it is a controversial topic which has generated much global debate. Research supporting the effectiveness of most supplements remains limited at present.

There are a variety of nutritional supplements in the market ranging from vitamins and minerals to herbs, sports nutrition products and natural food supplements. They come in many forms including pills, tablets, capsules, powders, and liquids (Dietary Supplements: What You Need to Know, 2020). Generally, supplements are only of use if your diet is inadequate or if you have been diagnosed with a micronutrient deficiency such as iron deficiency or vitamin B12 deficiency (Nutrition and Healthy Eating, 2021).

Sports nutrition supplements are thought to enhance energy, focus and performance for athletes, and include examples such as caffeine and creatine (Workout Supplements, 2023). In fact, the Pre-Workout Supplements Market was valued at USD 15.59 Billion in 2021, and it is expected to reach a whopping USD 28.68 Billion by 2028 (“Global Pre-workout Supplement”, 2022).

It is recommended that individuals review their diet and eating habits to ensure that they are having well-balanced, nutritious meals before taking supplements (Nutrition and Healthy Eating, 2021). It is also important to educate yourself on the potential benefits, risks or side effects, and the proper dose and duration of use of dietary supplements. You will find a wealth of information available through media, however, it is important to sperate fact from fiction (Dietary Supplements: What You Need to Know, 2020).

Safety and Effectiveness of Nutritional Supplements

Additionally, there is inadequate information concerning the safety and effectiveness of workout supplements. Certain supplements may interact with prescription or over the counter (OTC) medication, so consult your health care provider before taking dietary supplements (Dietary Supplements: What You Need to Know, 2020; Workout Supplements, 2023). And remember, “natural” does not necessarily mean safe!

There is also the ethical issue of using supplements for the purpose of enhancing performance, not to mention the issue of committing an anti-doping rule violation. Remember, you and you alone are responsible for taking supplements and facing potential health, legal or safety consequences.

What about probiotics?

According to the World Health Organization (WHO), probiotics are “live microorganisms that, when administered in adequate amounts, confer a health benefit on the host” (Hill et al., 2014). They help restore gut flora, improve the digestive system, fight disease, and maintain health (Harvard Health 2022).

The International Society of Sports Nutrition (ISSN) released a position statement in 2019 concerning the use of probiotics by athletes. They concluded that certain probiotics optimize the health of athletes by strengthening the immune system, reducing the severity of respiratory infections and gastric disturbances, and improving nutrient absorption in the gut (Jäger et al., 2019).

The “gut microbiome” – is there a connection between diet, gut flora and elite athletic performance?

The human gut is home to over 40 trillion microorganisms, collectively referred to as the gut microbiome or gut flora (The Nutrition Source, 2022). These microbes are influenced by factors like age, stress, diet, drug use and genetics. They play a critical role in digesting food, absorbing nutrients, synthesizing vitamins, and regulating the immune system (Mohr et al., 2020).

There is emerging evidence which suggests that gut microbes may influence athletic performance. According to a review article published in the Journal of Sports Medicine in 2022, several studies have reported differences between the gut flora of athletes and non-athletes. Physical activity appears to have a generally positive effect on gut flora by promoting diversity and abundance of “health-associated bacteria” (O’Brien et al., 2022).

Benefits of Saccharomyces boulardii for Athletes

The probiotic strain Saccharomyces boulardii CNCM I-745 is a unique probiotic strain studied in over 100 clinical trials and researched worldwide for over 65 years (Florastor, 2023).

S. boulardii can help athletes by:

Enhancing production of short-chain fatty acids
Increasing brush border enzymes (lactase, sucrase, maltase)
Helping to stimulate increased secretory IgA (the body’s most common antibody) to support a healthy immune system.

We leave you with this final pearl: “what and how much you put in your tank will determine how well you perform”.