Healthful Living: The Role of Macronutrients in Exercise

healthful living healthy New Years Resolution Nutrition nutrition after exercise What to eat


Every January, millions of Americans make New Year’s resolutions; often approaching old goals with renewed vigor and enthusiasm. A recent survey of U.S. adults showed that one of the most common resolutions for 2018 was to lose weight or get in shape. Among Millennials, the sense of feeling unhealthy is especially strong, with nearly 80 percent of adults under the age of 36 reporting that they “could be healthier”. It is common to feel like the amount of information about what to eat is difficult to understand given the seemingly daily deluge of fad diets and quick weight loss hacks on social media. But when one decides to embark on a new health, wellness or fitness journey, the sheer volume of information can often leave us feeling anxious and overwhelmed. MAC Fitness Solutions aims to support your fitness goals and we have connected with experts in both the nutrition and fitness fields that we will be featuring as part of a new Healthful Living Article Series.

Today, we are featuring an article from Ashley Acornley, MS, RD, CSSD, LDN, Registered Dietitian, Certified Specialist in Sports Dietetics, AFAA Certified Personal Trainer and Katie Holden, Dietetic Intern. Ashley is the Owner of Fueled and Fit LLC, a private practice in Cary, NC.

The Role of Macronutrients: Before, During, and After Exercise

Ashley Acornley, MS, RD, CSSD, LDN and Katie Holden, Dietetic Intern

Ever wonder how each macronutrient in food contributes to fueling and recovery for physical activity? Throughout this article, I will identify what the three primary macronutrients are and sources of each. Then, I will review the recommendations for when and how much of each to eat for optimal fueling and recovery.

What are the macronutrients, anyway? Carbohydrates, protein and fat are the nutrients that are used in the largest amounts by your body; hence their name macronutrients. Carbohydrates are the main source of energy for the body. There are two types of carbohydrates: simple and complex. Simple carbohydrates are digested faster and therefore, provide energy quicker. Examples include sugar, white bread/pasta/rice, fruit, and milk. Complex carbohydrates contain more fiber and therefore, have a delayed release in energy. Examples of these include whole grains and starchy vegetables.

Protein provides structure to things like muscle, organs, hair, skin, tendons, ligaments, etc. This macronutrient is also involved in enzymatic, hormonal and metabolic reactions. Protein can come from animal and plant sources. Animal sources include poultry, fish, beef, pork, eggs and dairy, while plant protein comes from beans, nuts, seeds, tofu, lentils, grains, etc.

Finally, fat assists in the absorption of vitamins A, E, D, and K; aids in immune function, cushions joints, helps regulate body temperature and can serve as an energy source for long-term, low intensity activities. Dietary fat can be unsaturated, which mostly come from plants (olive or canola oil, nuts & seeds, avocados) and fatty fish; or saturated, which mostly come from fried foods, packaged baked goods, higher fat dairy products and the fat on meat and poultry. Aim to get the majority of your fat intake from unsaturated sources.

So, how do we use each of these nutrients to optimally fuel performance? Let’s start by reviewing general recommendations for how to structure meals and snacks by using the plate method. In general, your plate should be comprised of ½ non-starchy vegetables and/or fruit, ¼ lean protein and ¼ starchy carbohydrate. A moderate amount of healthy fat should also be incorporated along with sufficient fluids. On hard training days, ½ of your plate should be starchy carbohydrates, ¼ lean protein and ¼ fruit and/or non-starchy vegetables. On light training days, reduce starchy carbohydrates to ¼ of the plate and increase fruit & non-starchy vegetables to ½ the plate.

Tip: include a variety of colorful fruits and vegetables on your plate to increase the types of nutrients in your diet. These nutrients can help reduce oxidative stress caused by exercise. Oxidative stress is an imbalance between the amount of damaging free radicals and protective antioxidants in the body. Vitamins A, C, and E are antioxidants found in foods such as dark leafy greens, broccoli, berries, citrus, carrots, sweet potatoes, avocado, nuts and seeds.

Now, how do you determine if and what to eat before, during and after a workout? Below are two questions to consider when deciding how to structure your meals around workouts:

  • Have you eaten a balanced meal or snack within the past 3-4 hours?
    • YES - you may or may not need to eat again before exercising. See next question.
    • NO - you should consider eating something before exercising. See recommendations below.
  • Is your workout longer than 60 minutes?
    • YES - you should consider eating and/or drinking something before, during, and/or after exercising. See recommendations below.

Pre-Workout Nutrition (for activity > 60 minutes): primarily focused on carbohydrates to FUEL.

  • If eating 30-60 minutes before exercise, consume carbohydrates that are easily digested.
    • Examples: fruit, sports drink, pretzels.
  • If eating 3- hours before exercise, consume a meal that is higher in carbohydrate, moderate in protein and lower in fat. Include complex, higher fiber (starch) and simple, lower fiber (dried fruit, non/low-fat dairy) carbohydrates.
    • Examples: turkey and cheese sandwich with a piece of fruit and chocolate milk, or low-fat Greek yogurt with fruit and a small salad with chicken.
  • Hydrate with 16-20 ounces of fluid.

Intra-Workout Nutrition: primarily focused on fluids, electrolytes and carbohydrates to REPLACE what is lost during exercise.

  • If a workout < 45 minutes, focus on hydrating with water.
  • If a workout is 45-75 minutes, focus on hydration with small amounts of carbohydrate throughout activity. For example, 3-8 ounces of sports drink every 15-20 minutes.
  • If a workout is 1-2.5 hours, consume 30-60g of carbohydrate per hour. For example, 1-2 handfuls of raisins or pretzels, or a serving of energy gel, chews or sports drink.

Post-Workout Nutrition: emphasizes carbohydrate and protein for RECOVERY. Aim to consume a snack or meal within 1 hour of exercise that is primarily carbohydrate with a moderate amount of protein. A 3:1 ratio of carbohydrate to protein is recommended.

  • Examples: chocolate milk, Greek yogurt with berries and granola, chicken stir fry with brown rice and vegetables, or baked salmon with roasted sweet potatoes and spinach salad.

Note: recovery nutrition is also important for the next 24-48 hours. Continue to follow general recommendations detailed above to promote optimal recovery.

Hydration: focus on fluid intake throughout the day to prevent dehydration and early fatigue. In general, drink half of your bodyweight in ounces of fluid.

  • Before exercise, drink 16-20 ounces at least 4 hours before exercise. Include 8-12 ounces of water 10-15 minutes before exercise.
  • During exercise, drink water or sports beverage every 15-20 minutes.
    • If activity is < 60 minutes, drink 3-8 ounces of water.
    • If activity is > 60 minutes, drink 3-8 ounces of sports beverage.
  • After exercise, rehydrate with 16-24 ounces of fluid for every pound of body weight lost.

In summary, the three macronutrients all play a role in optimal fueling and recovery. The timing and nutrient composition of meals can also influence performance and recovery. Sufficient fluid intake is also critical to prevent dehydration and early fatigue. My hope is that these simple tips can help increase the effectiveness and productivity of your workout.


Ashley Acornley, MS, RD, CSSD, LDN

Ashley is a Registered Dietitian and the owner of Fueled and Fit LLC, a private practice in Cary, NC. Ashley has been a Registered Dietitian since 2010 and has worked with a variety of clients in outpatient, gym, and corporate wellness settings. Ashley launched her own nutrition business in 2019 and enjoys the personalized time she gets to spend with each of her clients. She works with a wide variety of patients, but specializes in weight loss, sports nutrition, and women’s health. Her flexible food philosophy allows clients to reach their goals and gain a healthier relationship with food without any fads or deprivation involved.  In addition to individualized counseling, Ashley offers small group classes, lunch n’ learns, grocery store tours, meal planning, and virtual counseling. Fueled and Fit LLC is currently in network with Blue Cross Blue Shield and United Healthcare insurance plans, along with various self pay packages.


Facebook: Fueled and Fit LLC

Instagram: @fueledandfitllc


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