Before we tackle what you should (and shouldn't) be eating before, during, and after a run, it's worthwhile exploring what happens to your body when you run. So, let's start there.
Physiological changes that occur during a run
When you’re out on a run several physiological changes take place including:
Optimal nutrition can help lessen these effects, improve recovery time and help you perform at your best.
Fuel store depletion
No runner wants to ‘hit the wall’ or ‘bonk’ during a run. That said, many endurance runners have experienced this once or twice. Essentially, bonking occurs when your fuel tank runs out of gas (glucose). Since glucose is the preferred fuel of working muscles and the brain, bonking has both physical and cognitive consequences - neither of which are pleasant. Here’s how it works:
Glucose is the preferred fuel of working muscles during a run. Once available glucose is used up (around 45 - 60 minutes) your body starts using glycogen, the stored form of glucose, for fuel.
On average, both of these stores are depleted after 60-90 minutes of high-intensity endurance training or 120 minutes of moderate-intensity (~65% VO2max). This is when bonking sets in 
Fluid is another critical factor for running performance. Exercise rapidly increases your internal temperature and water is used to keep you cool through sweat. The harder you work and the warmer it is outside, the more water you need. Staying ahead of dehydration is essential for preventing heat exhaustion and heat stroke, especially on warm training days.
But more than that, getting enough fluid is critical for reducing the strain on your heart during a run, which directly impacts your running performance. Water also helps lubricate your joints, stabilize your heart rate, and access fuel locked up in your cells 
. Studies show that even a 2% dip in body mass due to fluid loss can impair endurance performance and capacity. At 5%, work capacity decreases by 30% (scary, hey) 
Gastrointestinal (GI) disturbance and immune system suppression
Cramping, nausea, and/or diarrhea (aka “runners trots”) affect many runners and if you’re one of those people, you’re certainly not alone. Although not well understood, GI symptoms during a run are thought to be related to reduced blood flow to the gut 
. In addition, multiple studies have linked endurance exercise to an increase in intestinal permeability (aka leaky gut) 
Changes in gut function during endurance exercise are also thought to disrupt normal immune function and increase susceptibility to illness, albeit temporarily 
. Adequate nutrition before, during, and after your run can help lessen these effects and promote rapid recovery.
How many calories do runners need?
You’ve probably heard about the importance of getting adequate calories during intense training periods, however, fueling for running isn’t just about calories in and calories out. The quality of what you eat matters too. But first, let’s talk about energy intake.
If you are running at moderate to intense levels, anywhere from 1-2+ hours a day, 5-6 days a week, your energy expenditure can be anywhere from 600-1000 calories/hour during a run (depending on your weight, sex, age, and miles per hour). When you factor that deficit into your daily eating plan, energy needs for runners can range between 2,500-7,000 kcal/day 
A simple way to ensure that your calorie intake matches your energy expenditure is to track your dietary intake in a food tracking program such as My Fitness Pal
. Tracking your intake for a few days can help identify dietary gaps, however, it’s important to keep in mind that calorie calculations are estimations.
No time to track your intake? Alternatively, you can pay attention to internal hunger and satiety cues and use those as a guide. Our bodies are pretty competent at letting us know when to eat and when to stop.
Either way, it’s worthwhile paying attention to calorie needs because negative energy balance, or constant low energy availability, can not only compromise your performance but also your physical health and the energy needs of runners can vary widely, depending on age, sex, weight, training load and various other factors. (Read about relative energy deficiency syndrome here
Now, let's get into specific nutrients.
Carbohydrates requirements for runners
Carbohydrates are the preferred fuel of the brain and working muscles and an important part of your pre- and post-run nutrition routine (you might even need them during your run too). Below are the reference ranges for carbohydrate intake per day, based on activity level:
Like Calorie intake, daily carbohydrate needs for runners fluctuate based on training load. Essentially, the higher the duration/intensity of your run, the more carbohydrates you need.
Carbs are especially important pre-run to top-off your fuel tank and after your run to replenish glycogen stores and promote recovery 
High versus low-glycemic carbs
Here’s the thing. Not all carbs are created equal. And what you reach for immediately before, during, or after a run should be different from the carbohydrates you choose for regular meals.
The glycemic index (GI) is a way of measuring the effect of carbohydrates on blood sugar. Carbohydrates that are classified as high-glycemic are rapidly digested and absorbed and GI score > 55. Carbohydrates with a GI score of 55 or less are more slowly digested and absorbed 
Generally, lower glycemic carbohydrates are a better option because they usually contain more fiber and provide long-lasting energy (see ya later, sugar crashes). But higher glycemic carbs like sports drinks and bananas have a place for runners - specifically before, during, and after a run.
High glycemic carbohydrates provide an immediate source of energy and gentler on your GI tract before and during a run, whereas low-glycemic, high fiber options like steel-cut oats, and barley, can leave you searching for a bathroom mid-run.
After a run, it’s all about kick-starting the recovery process as quickly as possible and rapidly-absorbed carbs are better for that purpose. High-glycemic carbs rapidly replete muscle glycogen stores, promote nutrient uptake to support muscle protein synthesis, and are generally better tolerated than low GI options.
High GI carb choices include white bread, white rice, cornflakes, instant oats, watermelon, rice crackers, sports drinks, very ripe bananas, pretzels, and sports gels.
How much protein does a runner need?
Carbs aren’t the only thing that runners should pay attention to - protein is also important. Protein is made up of amino acids and is essential for cell regulation, nerve function, and synthesizing new muscle after a workout 
. Moreover, eating adequate protein can be helpful for boosting satiety and promoting weight loss in some.
Many runners need more protein than the average person to support muscle protein synthesis and glycogen repletion after a workout. And this is especially true during heavy training/ high mileage periods. But it’s not just about the amount of protein you’re consuming-protein quality and timing also have a big impact on performance, recovery, and training progression.
The recommended intake for protein ranges from 0.8-1.2 g/kg/day but runners may need up to 2.2g/kg/day 
. This means for a 150lb athlete, average daily protein intake should be 80-150g, spread throughout the day with no more than 30-40g protein per meal/ snack for maximum utilization. Runners looking to optimize weight and body fat percentage and increase lean muscle mass may especially benefit from hitting this protein target.
To put it into practice: If you are eating 55% - 60% of your total calorie intake from carbohydrates, aim for 15 - 20% of your calories from protein 
Good sources of protein include lean, grass-fed meat, skinless poultry, Greek yogurt, low-mercury seafood, tofu, and beans. Whey protein or multi-sourced plant protein powders can also be helpful for meeting protein requirements on the go.
Fat requirements for runners
Fats insulate organs and cushion joints, and are an important source of energy, particularly during lower intensity exercise. While there is no evidence that runners need to consume a greater proportion of their calories from fat, choosing high-quality fats can support hormonal health and inflammation, both of which are a concern during prolonged high-intensity exercise 
. Furthermore, eating adequate fat can be useful for bumping-up energy intake during heavy periods.
The recommended daily intake for fat is 0.5–1.5 g/kg/day. If you are getting 55% - 60% of your calories from carbohydrates and 15% - 20% from protein, that leaves you with 20% - 30% of your calories coming from fat 
Heart-healthy, nutrient-dense sources of fat include nuts and seeds, avocado, salmon, trout, sardines, and extra virgin olive oil.
Omega-3 fatty acids
Omega-3 fats are a group of essential fats with big benefits for runners. They block inflammation high up in the inflammatory cascade and have been shown to be beneficial for muscle recovery post-exercise, heart health, liver function, metabolic health, and more [11
There are three dietary sources of Omega-3s: EPA (eicosapentaenoic acid), DPA (docosahexaenoic acid) and ALA (alpha-linolenic acid). Food sources of EPA and DHA include fatty fish such as salmon and tuna. ALA (alpha-linolenic acid) comes from plants foods such as flaxseeds, walnuts, and vegetable oils.
While flaxseeds and walnuts are nutrient-dense choices, most of the health benefits of omega-3s come from EPA and DHA food sources rather than ALA. To utilize ALA, our body has to convert it to EPA, however, the conversion rate is low (less than 5%).
Some research suggests that up to 6g of fish oil (2400 mg EPA, 1800 mg DHA) a day may be helpful for reducing muscle soreness after a vigorous exercise session, although this is an area of ongoing investigation 
How do special diets impact running performance?
Vegan, vegetarian, paleo, and keto have become more popular among athletes however, each of these diets has perks and pitfalls for runners.
Vegetarianism/ veganism for runners
Plant-based foods offer a variety of nutrients but eating exclusively plant-based comes with a few extra considerations for runners. First, you need to be mindful of your protein sources since plant-based foods tend to offer less protein per volume, and protein plays a critical role in recovery after a run.
Second, micronutrients such as B vitamins, iron, and zinc, also require extra attention, because these are less available/absent in plant foods and can dramatically impact athletic performance, energy levels, and overall health 
Finally, getting adequate calories to support running is another important consideration for vegetarian and vegan runners. Plant-based foods such as non-starchy veggies provide lots of nutrients for few calories which can leave some plant-based runners with an energy deficit. Incorporating calorie-rich plant foods such as nut, nut butters, hummus, avocado, and olive oil can help bump-up energy intake.
The keto diet is a high fat, very low carb eating approach and has become a popular weight-loss tactic in recent years. More than 75% of calories come from fat and another 25% from protein, leaving very little room for carbohydrates (<50g carbohydrate per day). As a runner, relying on fat (in the form of ketones) as your primary fuel source has limited and mixed research 
. Carbohydrate is the primary fuel of working muscles and severe restriction appears to have a negative impact on endurance performance 
The paleo diet focuses on lean meats, fish, fruits and vegetables, nuts, and seeds and omits processed sugars and starches, and grains. Some athletes feel better eating paleo because it relies more heavily on lean protein and healthy fats and de-emphasizes ultra-processed foods.
However, getting adequate carbs can be tricky, and careful planning is required on high training load days to support energy needs, prevent bonking, and promote recovery. While a paleo diet may be beneficial for endurance athletes many of these reports are anecdotal and more research needs to be conducted.
Whether you’re a keto-enthusiast or devout vegan, you should choose minimally-processed whole foods most of the time, and limit refined grains, added sugars, and saturated fats. There’s no “one size fits all” diet for runners and you have to do a little experimentation to learn what works best for you.
Nutrition recommendations before, during, and after a run
When you eat can be just as important as what you eat for runners.
Nutrition recommendations before a run
Fueling up adequately (and smartly) before a run can be the difference between crushing your workout and bonking midway through. The wrong type of fuel can not only leave you fatigued but also result in GI discomfort during your run. Here’s what matters.
Running in a fasted state
Many runners choose to do their running first thing in the morning, in a fasted state. If this is you and your run exceeds 60 minutes, you should plan on topping up on carbs and electrolytes mid-run (think sports gel) in order to maintain energy output and minimize stress on your body 
If you’re running fasted for 60 minutes or less, you probably don’t need to worry about fueling mid-workout but you should replenish both carbs and protein (and of course, hydration) immediately after your run.
Either way, if you feel light-headed, dizzy, or disoriented during a run you should stop, refuel and rehydrate. These are signs that your body is struggling and you should always listen to your internal signals.
2-4 hours before a run
Aim to eat your last full meal 2-4 hours before your run. Your goal should be a balanced meal that includes carbohydrates, protein, and fat. However, carbohydrates should be the focus with most runners needing somewhere between 50-100g of carbohydrate as part of their pre-workout meal. The aim of pre-workout fueling is to top off glycogen stores and provide readily-available fuel for muscles when you head out the door [16
Good examples of pre-workout meals include:
Oatmeal topped with banana, berries and nut butter
Sandwich on whole-grain bread with turkey, avocado, lettuce and tomato.
Whole grain toast topped with peanut butter and banana
Rice bowl with tofu, avocado, and baby greens
15-30 minutes before a run
Choose easily digestible carbohydrates (high-glycemic carbs) 15-30 minutes before your run. Avoid foods higher in fiber, protein, or fat, since these require more time for your body to digest and may increase GI discomfort during your run. Our top pre-workout snacks include:
Small energy bar
8 oz sports drink
What to eat during a run
If you plan to be running longer than 75-90 minutes, fueling mid-run should be a consideration. This matters even more if you’re running in a fasted state (i.e. first thing in the morning).
Your best bet is to plan for between 100-200 calories/hour (roughly 30-60g carbohydrate/hour). Many runners choose to split their intake into 20-minute increments to minimize GI discomfort. Sports gels, chews and drinks, honey sticks, bananas, and candy (yes, you read that correctly) are all popular, easily digestible choices for topping up your glucose supply mid-run 
. Mid-run fueling is all about getting in a little glucose, minus a grumpy GI tract.
How to refuel after a run
The right post-workout fuel, hydration, and supplements at the right time can accelerate recovery and provide a competitive advantage leading you into your next workout/ race. And what runner doesn’t want that? No one wants to feel like garbage during training or a race.
Before we get into the nitty-gritty about what to eat (and drink), let’s talk about when. The optimal time to refuel is 15-60 minutes post-workout 
. Basically, the sooner you can start replenishing fuel and fluid, the faster you begin recovering.
The three most important nutrients after a run are carbohydrates, protein, and fluid. Protein initiates muscle protein synthesis (MPS); carbohydrates replenish glycogen stores and promote nutrient utilization and fluid (either as water or an electrolyte beverage) remedies dehydration and restores electrolyte balance.
If you remember anything about post-workout nutrition it should be that a combination of carbohydrates and protein is more effective than either nutrient alone. In fact, research has shown that skipping carbs and consuming protein after endurance exercise reduces the rate of glycogen storage and, in turn, delays recovery 
Our favorite post-workout choice is a recovery smoothie that contains any combination of fruit + protein powder blended with water, but yogurt and granola, chocolate milk, and eggs on toast are also good options.
Within 60 minutes post-run aim for:
Carbohydrates: 45-90g depending on your body weight and intensity of your run. The longer or harder your run, the more carbs you need to replenish. Choose rapidly absorbed sources like sports drinks, fruit, juices, smoothies, white breads or bagels.
Protein: 25-40g (0.4 - 0.5 g/kg or 0.9 -1.1 g/lb) to optimize muscle synthesis and promote recovery 
. Protein sources rich in leucine (a branched chain amino acid) such as dairy products, whey protein, eggs and beef, have been shown to be especially effective for muscle protein synthesis 
Fluid: We get into this more below but a good rule of thumb is to drink 16oz (2 cups) of fluid for every 1lb (0.5kg) lost.
Hydration needs for runners
The importance of hydration and the role it plays in running performance cannot be overstated. Just about every biological process depends on a sufficient supply of water, so keeping yourself hydrated before, during, and after is essential to perform at your best. In fact, even as little as a 2% drop in body weight due to fluid loss can impair performance and leave you feeling fatigued and foggy during a run 
Here are a few guidelines for staying ahead of hydration as a runner.
Fluid needs throughout the day
Aim to consume ½ oz fluid per pound of bodyweight. For example, if you weigh 190lb (86kg), you should drink 95oz (3L) of water a day, plus additional fluid before, during, and after a workout 
. Water, sparkling water, and tea are all great hydration options.
Hydrating before a run
Adequate hydration pre-workout can help prevent dehydration and prepare your body for a long run. Urine that is light to pale yellow in color is a good indicator of optimal hydration status. Hydration needs will vary from person to person (we see you, heavy sweaters) but a good rule of thumb is to aim for 2 cups of fluid 2-3 hours before you run, and another cup of fluid 15-30 minutes before you lace up your sneakers and head out the door.
Water is generally the best option, however, some people may benefit from adding sports drinks into their pre-run routine, especially if you’re planning a longer run, if it’s hot outside and/or you’re a salty sweater.
Hydration needs during a run
Hydration needs during a run vary depending on sweat rate, training intensity, temperature and other factors. If you’re going to be on the road for over an hour, plan to consume 1-3 oz of fluid in the form of water and/or a sports drink every 20 minutes after 45 minutes of running to stay ahead of dehydration 
Sports drinks come with the added benefits of providing carbohydrate to fuel working muscles, and supplying electrolytes to replenish those lost through sweat. Again, fluid and electrolyte losses are very individual, however, a good starting point is to look for sports drinks with 14 g of carbohydrates, 28mgs of potassium, and 100 mg of sodium per 8 fl oz 
Fluid needs after a run
Once your run is over, it’s all about replenishing the fluids and electrolytes lost while you were pounding pavement. One easy way to measure fluid losses is to weigh yourself before and after a workout. You need roughly 16oz (2 cups) of fluid for every 1lb (0.5kg) lost. Don’t have a scale nearby? You can always use urine color as an approximation of hydration status. Urine lemonade or lighter generally means that you’re hydrated.
Do runners need electrolytes?
When you sweat, you’re not just losing water, you’re also losing electrolytes. Electrolytes are electrically-charged minerals including sodium, potassium, calcium, magnesium, and chloride. They are critical for muscle and nerve function and help regulate fluid balance.
Adding a sports drink or electrolyte supplement to your hydration routine before, during, and after your workout can help you stay stronger for longer during runs longer than 45 minutes, in hot temperatures, and/or you’re a salty sweater 
. One point worth noting is that sodium and chloride are lost to a greater extent than other electrolytes through sweat, and should be the main electrolytes in your electrolyte replenishment drink.
The best supplements and ergogenic aids for runners
The world of supplements can feel overwhelming, especially when you’re trying to optimize your health and performance. Protein powder, omega-3s, and electrolytes have already been covered, however, there are a few more that can be beneficial for runners. And sorry gang, none of them are silver bullets. (Read more about safe and effective ergogenic aids for runners here
Magnesium is an electrolyte that plays a critical role in cellular metabolism, protein synthesis, bone health, and muscle function, and is largely under-consumed. One of the best benefits of magnesium is that it promotes relaxation and sleep - both of which are much needed after a hard day of training. Plus, stress and sweat deplete magnesium stores making it a supplement even more worthwhile for those that love to run 
Magnesium-rich foods include spinach, peanuts, almonds, cashews, legumes, bananas, and whole grains. The recommended intake for women is 310mg-320mg/day and for men, 400mg-420mg/day) .
If you opt for a magnesium supplement, look for something with approximately 300mg of magnesium glycinate/citrate and take prior to bed.
Tart cherry juice
In recent years, tart cherry juice has been gaining traction as a pre/post-workout drink.Tart cherries (not the same as sweet cherries) are rich in antioxidants and polyphenolic compounds, and a growing body of research suggests that tart cherry juice may help improve performance and reduce muscle soreness when taken at the right time 
Tart cherry juice can be found in various forms including juice, capsule, and concentrate, and dosage recommendations vary depending on the preparation. If you want to experiment with tart cherry juice for running performance, look for a product without additives (no chemicals, please) and drink 8-10 ounces 30-60 minutes before a run and within the first 30 minutes post-workout to reap all the benefits.
Turmeric has been used for centuries as a traditional remedy for everything from digestive issues to skin health. Now, studies suggest that turmeric may have performance benefits too. Although turmeric contains many compounds, curcumin - the substance that gives turmeric its bright yellow hue - appears to be largely responsible for its anti-inflammatory benefits.
Research shows that 1000-1500mg of turmeric extract a day is helpful for reducing knee pain and improving functionality in people with osteoarthritis 
. In addition, some small studies indicate that 150-1500mg of turmeric daily, may promote post-exercise recovery and reduce muscle soreness, although not all trials have shown a positive effect 
. Combining turmeric with black pepper has been shown to improve the bioavailability of curcumin by up to 2000% and improve its effectiveness .
Good news, coffee drinkers! Coffee (specifically, caffeine) appears to be beneficial for running performance. Beyond giving you a nice alertness boost, caffeine has been shown to improve performance, speed, power, and endurance capacity when consumed before exercise [28
But that doesn’t mean that you need to go nuts. Anyone who’s overdone on coffee before will tell you that the jitters and heart palpitations are real and unpleasant.
So, what is the right dose of caffeine for runners? Based on the research, 3-6mg of caffeine/kg of bodyweight 15-60 minutes before exercise seems to be about right for most runners, although individual response varies and total caffeine intake shouldn’t exceed 400mg/day 
. To put it in perspective, 1 cup of coffee (8oz) provides about 100mg of caffeine.
One of the most well-known supplements in sports, creatine is a dietary amino acid that naturally occurs in muscle tissue. Although it’s typically thought of as a supplement for power athletes, runners may benefit from creatine too.
Evidence suggests that creatine aids ATP (energy) production and may increase strength, power, and output from muscle contractions. Studies also indicate that creatine may improve muscle recovery, glycogen replenishment, and potentially improve speed/output during a run 
If you’re thinking about starting creatine there are few guidelines for you to keep in mind. Creatine monohydrate is the most substantiated (and preferred) form of creatine. Research to-date recommends starting with a “loading dose” of 20g/day for 5 days, and then dropping to 3g - 5g/day thereafter for performance-enhancing benefits [30
One point worth noting is that creatine can increase water retention and some athletes experience modest weight gain as a result of supplementing creatine. Now, that doesn’t mean that creatine is a hard “no” if you’re trying to lose weight. Initial weight gain from creatine supplementation may eventually be offset by improved output and training gains associated with taking creatine.
Sodium bicarbonate (yep, that’s baking soda) might improve athletic performance in runners by buffering lactic acid production - the nemesis of running performance [32
]. As you’re probably aware, high intensity exercise causes lactic acid production, and this is a major contributing factor to muscle fatigue.
The recommended dosage of sodium bicarbonate for ergogenic benefits is 0.3g/kg of bodyweight, 60-90 minutes before exercise [6
]. One thing to keep in mind with sodium bicarbonate is that the gains can be modest and more relevant for short, explosive efforts [33
Beta-alanine is another compound that naturally occurs in muscle and like sodium bicarbonate, may help buffer lactic acid production. Research suggests that 4-6g/ beta-alanine/day, split over 2 doses, for up to 8 weeks, may enhance exercise capacity and reduce muscle fatigue during a run, especially during near-maximum or maximum efforts [34
]. Interestingly, tingling in fingers and toes is a common side effect of beta-alanine supplementation and some runners may benefit from starting at 2g beta alanine/day and slowly working up to 5g/day [34
Beets do more than just stain your hands. In fact, all that bright red mess may actually be worth it for runners. Beets are naturally rich in nitrates which increase nitric oxide levels in the body. Nitric oxide helps blood vessels expand and relax and beet juice may offer performance-enhancing benefits by increasing blood flow to muscles and promoting oxygen uptake [36
The recommended dose of nitrates for runners is 300-600mg (or 0.1mmol/kg of body weight), in the form of juice or food, 2-3 hours before exercise 
. For context, beet juice contains approximately 250mg per 1 cup and raw spinach contains approximately 300mg of nitrates per cup, so a single cup of spinach with your pre-run meal/snack may do the trick 
Providing your body with adequate fuel and hydration should be just as important as your training calendar and even minimal effort can yield a noticeable return on investment. No two runners are the same and while recommendations are useful, it’s important to experiment in training to find the nutrition tactics that work best for you. Your next PR is right around the corner with a thoughtful nutrition routine (and training plan)!
Disclaimer: The text, images, videos, and other media on this page are provided for informational purposes only and are not intended to treat, diagnose or replace personalized medical care.