Thu 27 Jul 2023 Dana Eshelman MS RDN CSSD METS

Training Nutrition & Hydration 101


Whether you are a new runner or a seasoned runner hitting your next PR, developing a nutrition plan that supports and nourishes your body is key to maximizing performance potential and longevity. For many athletes, there is a concern around:

  • Undesirable gastric distress that can happen mid-run

  • Sports nutrition products versus whole food

  • Hydration and electrolytes

  • Body composition

Let me start by saying, the human body is complex. You need fuel (carbs, protein and fats) to support your basic physiological functions as a living being. As a runner, your energy needs are higher than the average population, so it is crucial that you support the miles you are taking on with foods that provide your body with the nutrients and in the appropriate quantities it needs to train and live fiercely. 

A Little About Fueling

Nutrition is important not only the night before and the day of big training days and racing. What you do outside of those training days leading up to big training days and racing matters as well. 


Carbohydrates are the main source of fuel for those miles. Runners, and endurance athletes at large, benefit from consuming carbohydrates before and after training and racing to fuel your working muscles and replace the carbohydrates stored in your muscles and liver, known as glycogen.

Choosing complex carbohydrate foods over refined carbs will provide you with the most nutrition benefit in your daily nutrition. These include whole grains, fruit, vegetables, and beans, to name a few. Current carbohydrate recommendations for athletes:

  • Light intensity exercise (30 min/day): 3-5 g/kg/day

  • Moderate intensity exercise (1 hour/day): 5-7 g/kg/day

  • Endurance exercise (1-3 hrs/day): 6- 10 g/kg/day

  • Extreme endurance exercise (>4 hrs/day): 7-12 g/kg/day


Protein is important for building and restoring tissue. As an athlete, you should be consuming anywhere from 1.2- 2.0 g/kg body weight of protein. Lean protein sources should be your primary source. These include poultry, lean beef, fish, cheese, greek yogurt, cottage cheese, tofu, beans, edamame, lentils, 2% or less milk, or soy milk. Protein is best consumed consistently (0.25 to 0.4 g/kg) throughout the day to aid in muscle recovery, satiety and blood sugar balance.

Protein recommendations:

  • General public/ active people: 0.8-1.0 g/kg body weight/day

  • Non-endurance, exercise 45-60 minutes/day, or elderly: 1.0-1.2 g/kg body weight/day

  • Endurance and strength, exercise more than 60 minutes/day: 1.2-1.7 g/kg body weight/day

  • No benefit in consuming >2.0 g/kg body weight


Fat is essential for absorbing fat soluble vitamins (vitamin A, D, E and K), fighting inflammation, and providing cushion to your vital organs. Aim for 20 to 35% of your total calorie intake from fats. Great sources of healthy fats include nuts/seeds, nut/seed butters, avocados, avocado oil, olive oil, and fatty fish.

Your day to day nutrition plan is an opportunity to support your body, recover from training sessions and daily life, and reap benefits through muscle training adaptation. 

Pre-Run Nutrition + Hydration

If you are not currently fueling before your sessions, I want you to re-evaluate your strategy here. Would you race on an empty stomach? I sure hope not! 

The goal of pre-training nutrition is to provide your body with the energy it needs to do work. The primary fuel source here is carbohydrate. You may add some protein in for satiety and will want to limit both fat and fiber pre session. 

Hydration is another key component in supporting your training. This allows your body to adequately transport nutrients to your working cells as well as process out toxins, lactic acid, etc that are produced during training. You may consider electrolytes pre-session for hot, humid conditions and/or if you are a salty sweater. Hydration guidelines:

  • 30 minutes before: 10 ounces fluid pending thirst

  • 1-2 hours before: 16- 20 ounces fluid

You can follow these guidelines for your pre-training snack:

  • 30 minutes pre session: 0.5 gram carb/ kilogram body weight

  • 1 hour pre session: 1 gram carb/ kilogram body weight

  • 2 hour pre session: 2 gram carb/ kilogram body weight

  • 3 hour pre session: 3 gram carb/ kilogram body weight

For example, if you are training in the morning you may have a banana + 1 T nut butter and a slice of toast (50 to 60 grams of carbs) in the 30 to 60 minutes before you head out the door. If you have a session at 5pm, intentionally have a snack around 3:00pm that is carb focused such as Triscuits with hummus and a side of apple slices (50-60 g carbs).

If you are someone with a sensitive stomach, I promise there is hope for you! You can train your gut to tolerate fuel for both longer and shorter runs; it is so worth it! The key is starting simple and small with 15 to 30 grams of carbs in the 30 to 60 minutes before a session. You may gradually increase your carb intake pre run over 2-3 weeks to hit your goal carbohydrate intake pre run. Be sure to also hydrate as dehydration is a big culprit of gastrointestinal distress.

During Run Nutrition + Hydration

Fueling during your training session depends on the duration, intensity and goals of your session. Sessions that are less than 90 minutes in duration do not require fueling if you are providing your body with adequate nutrition before and after (be sure to check these sections out)! 

  • Endurance, intermittent, high intensity (1-2 hr): 30 to 60 g carbs/ hr 

  • Endurance (>2 hrs): 60 to 90; some research supporting up to 120 g carbs/ hr

Research shows the increased rate of carbohydrate intake decreases time to exhaustion and internal training load (ie. muscle damage). As you increase the duration of your training and rate of carbohydrate ingested, you will want to consider varying your carbohydrate sources (ie. glucose, fructose, sucrose (sugar), maltodextrin, cluster dextrin). Research shows multiple sources of carbohydrate with additional fluid consumed allow for maximal absorption in the gut, which decreases incidence of gastrointestinal distress.

Hydration is just as important (if not more so) as the fueling strategy and an area you can personalize based on sweat rate and sodium sweat concentration. To calculate your sweat rate you simply need a standard scale. I recommend doing this over an hour long session, without consuming extra fluids (consider a mild temperature day), after you have use the restroom to eliminate extra math here:

  • Sweat rate = (pre weight - post weight + fluids consumed during activity- urine volume/ exercise time in hours)

On average, an athlete’s sweat rate is 1.0 liters per hour. Environment (heat, humidity) has a role in sweat rate and can cause a higher sweat rate and, thus, increase electrolyte losses. Just a 2% body weight loss due to dehydration can increase your rate of perceived exertion and decrease performance.

Electrolytes (sodium, magnesium, potassium, calcium, and chloride) are another piece of the puzzle with sessions longer than 60 minutes. Replenishing electrolytes during these sessions is key for electrolyte balance.  You may test your sodium concentration with one of the many devices out there to give you an understanding of your sweat rate. You may already know if you are considered a “salty sweater” by noticing salt residue left on your skin or clothes after training, craving salty foods, and/or becoming lightheaded post training. For those salty sweaters, replacing electrolytes, specifically sodium, is increasingly important.

Consuming a low carbohydrate solution, 40 grams of carbs per liter, with 600 to 800 mg of sodium per liter will better hydrate you than plain water and will be an opportunity to get in some carbohydrate. The goal of adequate fueling and hydration during training and racing is to consume at least half of the calories you are burning per hour and maintain hydration losses to less than 3% of body weight.

Post Run Nutrition + Hydration

Many athletes struggle with poor appetite post training, especially when training in the heat. However, this does not mean to skimp on your nutrition or hydration. This means we need to get a little creative with how you will replenish muscle glycogen with carbs, rebuild muscles with protein, and rehydrate with electrolytes within the 30 to 45 minutes after you finish your training. The goal is consuming 0.25 to 0.4 g protein/ kg body weight, 1.0 to 1.2 g carb/ kilogram body weight, and 20 to 24 ounces of fluid per pound lost. Some great options that accomplish all the above and/or if you have a poor appetite post training:

  • Protein smoothie 

  • Recovery drink powders

  • Good ol’ chocolate milk

If your training session falls before a meal, then consider replenishing with a complete meal with 20-24 ounces of fluid within the 30 to 45 minutes post session. Examples include:

  • Breakfast hash - sweet potato hash, eggs, chickpeas, spinach, mushroom, tomato, pesto

  • Burrito bowl - rice, pinto beans, shredded chicken or tofu scramble, fajita veggies, corn, guac

  • Turkey wrap - whole grain tortilla, turkey slices, hummus, romaine lettuce, bell pepper strips, onion

Fueling for performance is not just for elite or seasoned athletes, it is for everyday athletes, active individuals. Use food as a way to fuel your passion! Take home points:

  • Time your nutrition to fit your training by increasing carbohydrates before and after sessions and finding a balanced plate of protein, fat, carb and color the remainder of your day. 

  • Plan your training sessions to fall before a main meal, so you are able to refuel according to your schedule

  • Hydrate according to thirst

  • Listen to your body and what it is asking you to fuel and refuel with

Your nutrition and hydration strategy is highly dependent on your preferences, the duration and intensity of training you are doing, the season of training you are in and what feels best for you. The BEST nutrition plan is the one that fits your lifestyle.

If you need help with your fueling or hydration strategy, connect with a sports dietitian to help develop a personalized plan for you!

** To get your weight in kilograms (kg), divide your weight in pounds by 2.2.

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