Nutrition & Hydration to Optimize Athletic Performance

When it comes to maximizing exercise and sports performance, proper nutrition and hydration play key roles. Eating well for both training as well as recovery are equally important. It is a cyclical process. The food we eat leading up to an event impacts blood sugar stability and influences how much energy reserves are available to the muscles during activity. Adequate nutrition afterwards ensures energy stores are replenished, muscles are repaired, acute inflammation is brought down, and hydration is restored.

It is the position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine that the performance of, and recovery from, sporting activities are enhanced by well-chosen nutrition strategies.

This is the first blog post in a series on nutrition for athletics. We will start by focusing on nutrition for training and exercise. Here are some guidelines to follow that will enhance performance.

Maximize your nutrition by choosing nutrient dense foods

The best way to maximize energy gained from food is to choose nutrient dense foods. Doing so will maximize the nutrition you take in with every bite. The best way to achieve this is by making whole foods the foundation of your diet. Whole foods are as close to as found in nature as possible, so often single ingredient foods. Examples include brown rice, fish, oats, banana, broccoli, eggs, etc. Start with whole foods as the foundation.

The second step to increasing the nutrient density of your diet is to include a variety of plant foods from all food groups and of all colors across the color spectrum. Doing so will optimize the quantity and breadth of antioxidants, anti-inflammatory compounds, vitamins, minerals, amino acids, and hydration you take in from food. Whole plant foods are naturally nutrient dense. Include plant foods with every meal you consume.

Avoid ultra-processed foods

The more processed a food gets, the more nutrients, fiber, protein, healthy fats are stripped. In the making of ultra-processed foods, food parts are isolated into ingredients like corn syrup, soy protein isolate, or vegetable oil, and then combined with preservatives, flavorings, synthetically derived vitamins and minerals, and food grade chemicals deemed generally recognized as safe. The result is far from what is found in nature, less recognizable to the body, and less nutrient dense.

The body responds best to foods in their whole form. There is a concept called food synergy- meaning the benefit of the whole is greater than the sum of its parts. Nutrition is a complex chemical process that occurs with every bite of food we consume, so complex that the workings cannot be replicated with isolated components of foods. Ultra-processed foods are composed of just that- isolated food parts. Phytonutrients also cannot be extracted into a pill form or infused into a food and treated the same way in the body, studies have tested this comparison. When we eat a variety of foods in their whole food form, antioxidants are enhanced, and nutrients interact in favorable ways for our health.

Maximize energy stores by including adequate amounts of carbohydrates

According to the joint position paper between the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine entitled Nutrition and Athletic Performance, “there is significant evidence that the performance of prolonged sustained or intermittent high-intensity exercise is enhanced by strategies that maintain high carbohydrate availability (ie, match glycogen stores and blood glucose to the fuel demands of exercise), while depletion of these stores is associated with fatigue in the form of reduced work rates, impaired skill and concentration, and increased perception of effort.”

Carbohydrates are the macronutrient, meaning nutrient required in large amounts, that the body breaks down into glucose and eventually glycogen. Glucose is for immediate use and glycogen is the storage form of glucose which is deposited in the muscles and liver. Muscle glycogen is utilized during exercise and liver glycogen is largely what stabilizes blood sugars in between meals and during exercise. Both endurance and resistance exercise depend on glycogen availability. Depletion of these stores as well as dehydration are rate limiting factors, on a physiological level, that will lead to fatigue.

How much carbohydrates is recommended?

The amount of carbohydrate required depends on the individual, body weight, and the intensity and duration of exercise. In general, the more intense the activity, the greater the % of calories that should come from carbohydrates and the lower the intensity activities, the % of carbohydrates can shift down. For moderate intensity exercise lasting 60 minutes per day, carbohydrate needs are 5-7 grams / kg of body weight. For an individual weighing 150lb, this amounts to 340-477 grams per day, spaced out throughout the day. For moderate-high intensity lasting 1-3 hours per day, carbohydrate needs are 6-10 grams / kg of body weight. For a 150lb individual, this amounts to 409-682 grams of carbohydrate per day, spaced out over the course of the day. Very high intensity training of more than 4-5 hours per day is even higher and low intensity exercise falls below the moderate range. Specifics on these ranges can be found here

Carbohydrates are essential for the athlete as well as overall health. The best way to optimize glycogen stores is to eat carbohydrate rich foods daily and with every meal. Familiarizing yourself with portions of carbohydrates can help gauge if you are consuming enough each day. For example, per one cup serving, rolled oats provides 27 grams of carbohydrates, brown rice- 45 grams, beans- 40 grams, and sweet potato- 27 grams. To maximize the nutrition gained from each food, choose a variety of whole food sources. Dense sources of carbohydrates are whole grains, pulses, beans, legumes, and starchy vegetables such as sweet potatoes, parsnips, corn, and winter squash.

Include adequate amounts of protein

Protein plays a part in numerous functions in the body such as digestion, energy production, muscle contracting, forming hormones, providing structure, balancing fluid, supporting immune health, and facilitating muscle repair and rebuilding. Protein is not the most efficient energy source, so for protein to be utilized for essential functions, it is important to consume enough carbohydrates and fat.

For athletes, protein needs are higher than the average individual and the amount needed increases as the intensity of training increases. The recommended range for athletes is 1.2-2.0 grams / kg of body weight per day. For an individual weighing 150lb, this amounts to 82-136 grams per day. Intake should be spaced throughout the day.

Focus on hydration

To ensure you are continually hydrated, pay attention to the color of your urine. Aim for a pale-yellow color like light lemonade. The American College of Sports Medicine advises athletes consume 500ml (17 oz, or just slightly over 2 cups) of water 2 hours before exercise to allow time for excretion. To get more specific, ~2-4 ml / lb of body weight 2-4 hours of exercise. Coming into an event hydrated and then maintaining hydration throughout will help maximize performance.

Dehydration will increase body temperature and put more strain on the cardiovascular system. It will also lead to fatigue, muscle cramping, and may even hinder coordination. During exercise it is advised to not loose more than 2% of body weight. Weighing yourself before and after training can help you determine how much water you need to consume to prevent too much loss.

If you exercise regularly and are training for an event, aim to consume ½ – 1 fluid ounce of water per lb of body weight in a days’ time. During more active seasons, aim for the upper range, and during less active times, aim for the lower range. For a 150 lb individual this equates to 75-150 oz range, or 9-18 cups of fluid.

Include enough nutrition and hydration during exercise

For exercise less than 60 minutes, it is typically not necessary to consume a sports drink or anything other than water. For intense activity lasting longer than 60 minutes, The American College of Sports Medicine recommends 30-60 grams of carbohydrates per hour. Consuming 600-1200 ml (2.5-5 cups) fluid that contains 4-8% carbohydrates and 500-700 mg sodium per hour during exercise lasting 60 minutes can promote hydration, prevent hypoglycemia (low blood sugars) and hyponatremia (low sodium blood levels). The BEST way to determine what your body needs for an event is to experiment within these guidelines while training. Relying on thirst to signal fluid needs during exercise is not reliable. For more on the specifics of hydration needs categorized by sporting event and environment, click here.


Lauren Zimmerman

About the Author

Lauren has been a registered dietitian for 6 years and helps others develop practical and enjoyable lifelong nutrition habits to improve health, well-being, energy levels, confidence, and digestion. She focuses largely on a whole food, plant-based nutrition approach to health.