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Nutrition For The Modern Athlete

Updated: Jul 13, 2021

Whether you're a decorated Olympian, professional athlete, or weekend warrior taking breaks from dad-life in the local crossfit gym - every athlete deserves to perform at their full potential.

But a simple Google of "sports nutrition" could send you a thousand different ways. And for a good reason. There's simply no one-size-fits-all approach to sport dietetics.

What any athlete requires nutritionally to improve their performance depends on a variety of factors such as gender, age, body-weight status for their sport, current dietary and lifestyle patterns, climate conditions, type of activity and where they currently reside in their season. Regardless of these specifics however, it’s important all athletes take into account two careful considerations: the nutrient density of their diet (the quantity of each macronutrient needed), and the timing of that nutrition (frequency of meals and snacks in a day).

So let's jump into it. What role does nutrition play in athletic performance anyhow?

"Performance Nutrition" is simply the concept of using food and fluids to enhance training and performance, speed up recovery and healing, prevent injury, and improve body composition.

We'll move through these in chronological order, starting first with nutrition for enhanced training and performance.

Enhancing training and performance:

Optimal Energy Intake:

An athlete's resting metabolic rate (or RMR), the amount of calories burned at rest, is best calculated using a metabolic cart to accurately decipher the amount of O2 consumed and CO2 produced by the individual. But since the majority of us don’t have regular access to pricey medical devices, we can form an educated estimate using the Harris-Benedict equation:

Women: BMR = 65 + (4.35 x weight in pounds) + (4.7 x height in inches) – (4.7 x age in years)

Men: BMR = 66 + (6.23 x weight in pounds) + (12.7 x height in inches) – (6.8 x age in years)

Keep in mind these estimates don't account for additional calories burned through digestive metabolism (also known as the thermic effect of food), cognitive exertion, healing, temperature regulation or other means of bodily energy use beyond basic organ maintenance. So if they look a little low, take that information with a grain of salt.

With that said, it's time to consider an appropriate activity factor to account for calories burned during exercise.

Activity factors:

For light exercise/sports 1-3 days/week: RMR x 1.375

For moderate exercise/sports 3-5 days/week: RMR x 1.55

For hard exercise/sports 6-7 days/week: RMR x 1.725

For very intense exercise/sports 7 days/week or 2-a-day workouts: RMR x 1.9

Now that we have those energy needs pinned down, let's take a look at how we can break up those calories into macronutrient ratios that will best serve the competitor.

Macronutrient Recommendations for Athletes:


In order to properly restore glycogen levels on a daily basis (a form of stored energy utilized in exercise) an athlete should consume between 6-10 grams of carbohydrates per kilogram of body weight each day. Don't know your weight in kilograms? Simply divide your weight in pounds by 2.2. For example, a 154 pound athlete (154/2.2 = 70 kgs) would need 420-700 grams of carbs per day. Now obviously that’s a big range - so lets break it down by sport here.

Strength and power athletes: 6-7g carbs per kg body weight

Endurance athletes: 7-10g carbs per kg body weight

Ultra-endurance athletes: may need 10-12g carbs per kg body weight

However, some elite trained endurance athletes may sustain on lower amounts (3-5g carbs per kg). This might be due to weight loss efforts, or because of the research suggesting that training on decreased glycogen stores may induce gene expressions that increase training adaptations such as burning fat for fuel. However, some individuals are responders to this low-carb fat-burning adaptation, and others are not. The catch is, it takes the body an average of two months to reveal how any one competitor may fare. So if training on lower carbs is something you'd like to try out, be sure to arrange that test-drive for the off-season.

"But wait, what's the worst that could go wrong?"

While low-carbs diets may not compromise performance according to the limited research we have on the subject, they do tend to increase the ratings perceived exertion (RPE) amongst athletes giving starch-restriction a go. Meaning on a low-carb diet, training at a seven feels like you're training at a ten. This is how we tell if someone is responding well to a low-carb diet and successfully transitioning to burning fat for fuel, or if they are simply not a good candidate for skimping on the grains. If RPE increases overtime and actual performance exertion remains the same, it's time to ditch the low-carb train.


It's no secret that athletes require extra protein in order to replenish those amino acids used up for energy, promote the synthesis of oxidative enzymes/mitochondria, prevent sport's anemia, and account for losses during exercise (in sweat, urine, and the GI tract). In fact, most athletes need about 20 additional grams of protein per day compared to normal individuals. But what about individual variability? How can an Olympic swimmer and a weekend gym-rat be expected to thrive off of an identical recommendation?

Since you asked, let's take a look at the optimal protein intake levels for each style of physical activity.

Optimal Protein Intake Levels (per day):

0.8g per kg body weight for a sedentary individual

1.1-1.4g per kg body weight for aerobic endurance athletes or strength-trained athletes looking to maintain their current muscle mass.

1.4-1.7g per kg body weight for intermittent high-intensity sports (like soccer) or weight-restricted athletes (trying to cut weight but maintain muscle mass).

1.5-1.8g per kg body weight for strength/power athletes (and up to 2g per kg if looking to increase their muscle tissue or if not taking in adequate calories).

It's important to note here that no study ever published in the realm of sports nutrition has ever demonstrated any benefit in performance exceeding 2 grams of protein per kilogram body weight per day (although many athletes think more protein is better).

In fact, making muscle gains may require less protein than you might think.

Let's walk through a brief math problem:

Say an athlete's goal is to gain one pound of muscle mass per week. Let's pretend they're 154 pounds. A 154 pound, or 70kg, athlete’s protein RDA (recommended daily allowance) is about 56g per day. 1 pound of muscle is 454 grams, and muscle is 22% protein. 454 x 0.22 = 100g of protein in 1 pound of muscle. 100 grams/7 days = about 14 grams of protein per day of additional protein needed to put on that muscle.

Now, athletes may use up another 20g protein during exercise.

So to summarize their daily protein needs: 56g needed at baseline + 14g to put on that pound of muscle each week + 20g to account for the losses through exercise = 90 grams protein per day.

90g/70kg = 1.29 grams protein per day! That's all it would take for an athlete that size to grow muscle fast. That's hardly a prescription for steak and eggs on the daily.


Here's where things get interesting.

We know that endurance training induces adaptations that enhance fat utilization and aerobic exercise performance. Specifically, when we train:

- We increase the expression of genes in skeletal muscle that increase enzymatic capacity for fat oxidation.

- We increase muscle triglyceride storage

- We increase the sensitivity of muscle and adipose cells to epinephrine

- And we increase transport of plasma free fatty acids into muscle during exercise

With these adaptations in mind, one would think we would be fat-torching machines when we train. But this doesn’t really play out.

Each one of us has a minimum of 80,000 calories stored as fat. In theory, we should be able to go run 100 miles without hitting of wall because of all that storage, but unfortunately that doesn’t happen. Why might that be?

Suggested limiting factors for this are that there is inadequate free fatty acid mobilization from the adipose tissue. Or maybe the free fatty acids are able to get out of the adipose tissue, but are limited in transport to the muscle cell to be used. Or more likely, it's what we call "feedback inhibition" - all the carbohydrate oxidation during exercise inhibits significant fat oxidation from taking place.

What we do know is that diets containing 20-30% of energy (calories) from fat appear to be reasonable for endurance athletes. Less than 20% may not be adequate for hormone production and insulation needs, and greater than 30% of energy from fat may impair performance and hinder cognitive function.

Let's put it all together now.

Summary of Daily Needs for Enhanced Training & Performance:

Carbs: 6-10 g/kg/day

Protein: 1.1-1.8 g/kg/day

Fat: 20-30% of overall calories/day

Now to address the second critical consideration in sports dietetics: How do we fit this all into the day?

First and foremost, we want to ensure fuel in consumed before and after performance. Before competition, carbs provide the most benefit to an athlete when consumed between 1 and 4 hours leading up to the event. See below for time-sensitive dosages.


4 hours prior: 4-5g per kg body weight

3 hours prior: 3-4g per kg body weight

2 hours prior: 2-3g per kg body weight

1 hour prior to the event: 1-2g per kg body weight (ideally in an easily-digestible form, such as liquid carbs/energy drinks)

This poses the question, will eating carbs immediately before an event improve performance? Surprisingly, yes.

Even if you have carbs less than ten minutes before an event (as a beverage) it can boost performance 2-12%, not because they're rapidly digested and utilized for fuel but rather because sensors in the mouth tell the brain fuel is on the way.

Research has proven this by studying the performance of athletes following their gargling carb-rich fluids prior to competition without even swallowing them. Their performance improved regardless.

For reference however, peak carb use occurs 75-90 minutes after ingestion, so having carbs right before a lengthy endurance performance can be very beneficial. Having carbs during prolonged endurance exercise can also enhance performance, as well as help maintain a balanced blood sugar, provide energy to muscle cells, and reduce those ratings of perceived exertion. The goal here is to have 1 gram of carbs per minute, or 60 grams of carbs per hour exercising. Just be sure to break that up into smaller boluses every 15-20 minutes, as opposed to slurping down all your glucose at once.

*Note: For athletes working out for 45 minutes or less, no need to drink/consume carbs during activity. If working out at max VO2 for 45-60 minutes, athletes should consume about 30 grams of carbs per hour. For team sports lasting 90 minutes, up to 50 grams/hour. For submaximal exercise lasting more than 2 hours, up to 60 grams/hour. For near-maximal and maximal exercise lasting more than 2 hours, up to 50-70 grams/hour. And for ultra-endurance events, 60-90 grams/hour. But again, this requires slow training of the stomach in order to tolerate such fuel mid-competition.

When it comes to nutrition after a workout, carbohydrates are critical as a means to restore depleted glycogen. This is especially important if there are multiple workouts in a day or repeated bouts of prolonged, intense exercise on the same day or in consecutive days. Within 30 minutes following the completion of physical activity, it is recommended that athletes consume 0.6-0.8 grams of carbs per kg body weight.


Protein is most effective when consumed before and after a workout - preferably with carbs. Specifically, 0.1-0.26 grams of high-quality protein per kg body weight is needed post workout (about 7 grams minimum for a 70 kilogram athlete).

Not in the mood for meat or fish fresh off the trails? No worries! Plant-based proteins are some of the healthiest, most fibrous, disease-fighting foods on the planet - and are perfectly adequate for post-workout protein consumption.

Great sources of plant-based protein include foods like tofu, tempeh, black beans, pinto beans, kidney beans, lentils, chickpeas, nut butters, hemp seeds, plant-based yogurts and veggie burgers.

It's widely known that protein is critical after workouts. But it's especially critical if an athlete's carb intake is modest – in which case protein helps accelerate the rate of muscle glycogen synthesis and storage repletion. More ideally, a combination of carbs and protein will enhance recovery, support lean body mass, and refuel that energy lost in competition. The ideal ratio here is 3-4 grams carbohydrates per 1 gram of protein.

To summarize, consume the following post-workout fuel within 30 minutes of ending physical activity:

0.6-0.8 grams carbohydrates per kg body weight

0.1-0.26 grams protein per kg body weight

Recovery snacks can come in a variety of forms, with the most convenient options typically presenting as recovery shakes, protein smoothies, a large apple or banana with peanut butter, trail mix, protein bars, sandwiches, or yogurt parfaits. Heading straight to a balanced meal here works too.

Improving Speed & Recovery:

Snowballing off those post-workout recommendations, one of the best ways to improve speed and recovery is to take advantage of that recovery window.

Research shows we achieve better gains, leaner bodies, and more adequate glycogen store repletion when we eat within 30 minutes of ending a workout.

Every meal and snack should have carbs and protein, ideally in a ratio of 3:1 or 4:1 carbs to protein.

It's also critical to incorporate anti-inflammatory foods in order to reduce pain and fatigue as well as recovery time. Fruits, vegetables, whole grains, beans, garlic, ginger, apples, celery, parsley, tomatoes, turmeric, green tea, walnuts, flaxseeds and omega-3 fatty acids are the most powerful inflammation-busters known to man.

Similarly, avoiding junk foods, high fat meats, processed meats (bacon, sausage, salami, etc.), sugar, fast foods, saturated and trans fatty acids can aid in keeping inflammation at bay, as these increase inflammation, pain, and the risk for chronic disease.

For more on nutrition for inflammation, be sure to check out this post here.

Preventing Injury:

One of the main reasons athletes can be at risk for injury is that they’re not meeting their macro/micronutrient needs, or because they are eating foods that promote chronic inflammation.

Research shows athletes that consume unbalanced diets, restrict their energy intake, implement severe weight-loss practices or who omit one or more food groups from their diet are the ones most likely to get injured.

Hydration is another critical aspect of injury prevention. To stay adequately hydrated, an athlete must include plenty of water or sports drinks, electrolytes, and carbs from fruit, sweet potatoes, rice, bread, and veggies. Each gram of carbohydrate holds 3-4 grams of water (which is why low-carb diets lead to rapid water-weight loss). If any of these are deficient, it will decrease performance and increase the risk of injury for the athlete.

How to Calculate Your Hydration Needs:

Take your weight in pounds and divide by 2. BOOM.

That’s how many ounces of water you need each day at minimum. In addition to that, for every pound lost during training, add 20 oz. of fluid for recovery (for example, if you lose two pounds at practice, add an additional 40 oz. to that baseline minimum fluid requirement).

Hydrating fluids include water, propel, coconut water, G2, Gatorade and products of the like. Milk, juice, alcohol, and soda cannot be counted as hydrating fluids, as they behave differently in the body upon digestion. If an athlete is a particularly "salty sweater", things like coconut water, propel, G2 or Gatorade would be preferred over water as a means to replenish that excreted sodium.

In the case that an athlete is drinking plenty of fluids, but still showing signs of dehydration (thirst, dizziness, lethargy, headaches, etc.) – electrolyte imbalance may be the issue.

Each pound of sweat contains 400-700mg sodium, and 80-100mg potassium.

And sure, athletes may lose on the lower end of this if they are well-adapted to the particular climate they train in. Even still, during two hours of exercise, an athlete may lose from 1800-5600mg sodium and 300-800mg potassium. As a Dietitian, I always promote focusing on food first for electrolyte repletion. Things like soups, pickles, pretzels, watermelon, celery, bell peppers, strawberries, cantaloupe, cucumbers, tomatoes, spinach, and broccoli are all fantastic foods for electrolyte repletion. And those last several are not only rich in electrolytes, but water too - which may help with overall with hydration status.

Salty sweaters may need to add supplemental electrolytes to fluids just before bed, as well as before and after practice.

How to tell if you're a salty sweater: If you feel salt atop your skin after sweat dries or find a white chalky coating on the inside lining of your hat or clothing, chances are you fit the bill. Special patches sold online or at various sporting goods retailers can also help detect the sodium content of your sweat as well.

Improving Body Composition:

When it comes to optimizing body composition, front-loading calories early in the day is key. Eating breakfast within one hour of waking up can help increase one's metabolism, boost energy levels throughout the day, and even improve academic performance and cognitive function. Not to mention balanced breakfasts can also help prevent those night-time binges that result from perceived restriction on a subconscious level.

Eating within 30 minutes of working out helps us replace our energy stores and build muscle. But similar to injury prevention, hydration is also critical for success in this department. Adequate fluid intake not only supports healthy muscles and joints, but aids in fat loss as well, allowing the body to properly break down adipose tissue.

Additionally, if an athlete is looking to put on muscle, a bedtime snack containing protein can help.

Now for the frosting on the cake: Supplements.

The competitive edge? The secret to your best time, heaviest rep, or most crisp performance ever? Maybe, but maybe not.

Before considering any dietary supplement it's important to pose three questions:

- Is it legal?

- Is it safe?

- Is it effective?

Dietary supplements banned in sports include anabolics such as androstenedione, and stimulants such as ephedrine. But that doesn't stop certain supplement companies, in an effort to deliver life-changing results to their clientele, from including these banned substances in their product without proper disclosure on the label.

Aside from that, even if a supplement is widely considered safe, it may contain more or less of the active ingredient than is listed on the label. We see this a lot with caffeine in the industry. The more milligrams of caffeine a brand can pack into their product, the more of a detectable "boost" in performance a client is likely to experience, leading to return customers and better sales. What's more, many athlete's think if one is good, ten must be better - which is another reason things can get toxic in this department.

Luckily, certain third-party sites exist purely to help the unassuming public determine which supplements are safe, effective and an accurate reflection of what's listed on the label. Others help break down the latest research behind performance, and offer up product suggestions that may be in line with an athlete's specific goals and needs.

Here are a handful of my favorites: – Serves as a third-party tester of supplements and medications. Determines if what is on the label is actually in there, if it's effective, if so in what dose, and who it may be contraindicated for. There’s both a free and paid version of this site (about $45/year to access all supplement reviews in full). - Similar to the previous reference, but with an emphasis on natural remedies, extracts and plant compounds. – The Collegiate and Professional Sports Dietitian's Association. This site has great handouts on all things sports nutrition and performance. - This site offers a variety of general sports nutrition fact sheets from the Academy of Nutrition & Dietetics. – The Gatorade Sports Sciences Institute. This site contains links to research, sports science and expert panels on athletic performance and nutrition.

Thank you all so much for tuning today. I hope you learned something new and empowering here, and that this information serves your athletic endeavors well.

Still have questions on frequent cramping, carb-loading, intermittent fasting, or looking for a summary of which products, proteins and supplements are most often recommended for your unique sport or activity?

Feel free to book a private session with me by reaching out via email. You can take a look at my services packages and pricing, linked here.

Before you go, be sure to leave a comment over on my Youtube, Instagram, or TikTok to let me know what kind of content I can create to best serve your mind and body well this season and beyond.

Until next time!


This post was written & medically reviewed by a Registered Dietitian Nutritionist.

Grace Pascale, MS, RDN. Grace Pascale Nutrition.


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