The Runner’s World Guide to Nutrition and Fueling: The Runner’s Diet

Runners have very specific nutritional needs that differ from less active individuals.Endurance training requires additional energy and carbohydrates, along with enough protein and fat to support training and recovery. But balancing those fueling demands with the principles of everyday healthy eating can be confusing.In The Runner’s World Guide to Nutrition & Fueling, an exclusive program hosted by Mireille Siné, our experts explain how to build a healthy, sustainable runner’s diet—and how to adapt it through every training phase and stage of life.What You’ll LearnIn The Runner’s World Guide to Nutrition and Fueling, we’ll teach you:The key questions to ask when evaluating your diet Why “winging” your nutrition doesn’t work How to fuel consistently throughout the year Which mainstream diets best support runners’ health and performance How to pursue weight loss or weight management without compromising your training What vegan runners and runners with celiac disease should consider Watch VideoGo DeeperBuilding a Healthy Runner’s DietA healthy runner’s diet should provide enough energy and nutrients to support your training while remaining practical and sustainable. Start by asking yourself a few basic questions:1. Are you eating regularly? Aim to eat meals and snacks consistently throughout the day rather than routinely skipping them. Depending on your schedule and training, that may mean eating every two to three hours.2. How do you feel following the Athlete’s Plate? This framework offers different plate-building guidelines based on training intensity. Use it as a starting point and pay attention to how you feel before adjusting accordingly.3. Are you missing any major food groups? Consider whether you regularly eat fruits, vegetables, carbohydrates, protein, and healthy fats. If something is consistently missing, make a realistic plan to add it.Fueling Every Training PhaseConsistently nourishing your body throughout the year is essential. If you abandon your fueling habits during the offseason, returning to structured training may feel like an uphill climb, explains performance dietitian Briana Butler, MCN, RDN, LD. Maintaining a solid foundation allows your nutrition to feel like “hills and valleys versus mountains and valleys,” says Butler.Sports dietitian and clinical exercise physiologist Jason Machowsky, MS, RD, CSSD, CEP, CSCS, recommends adjusting your plan for each training phase—base, build, peak, taper, and recovery—based on your weekly volume and goals. For example, you may need to increase your overall carbohydrate intake as mileage rises during a build or peak phase. A registered dietitian nutritionist can help you adjust throughout your training cycle.Be Cautious With Fad DietsIf a diet restricts the foods your body needs for running, it probably isn’t the right choice for your training. “Nine chances out of 10, a lot of those fad diets are not actually built for athletes,” explains Butler.Nutrition is highly individual, but diets that emphasize fruits, vegetables, whole grains, protein, and omegas tend to align well with endurance athletes’ needs. The Mediterranean and DASH (Dietary Approaches to Stop Hypertension) diets are two solid examples that include a wide variety of foods rather than eliminating entire food groups.“The goal should be to overlay your performance nutrition on top of health and wellness patterns to ensure you’re giving your body what it needs for performance in addition to health.”—Jason Machowsky, sports dietitian and exercise physiologist How Nutrition Needs Change as You Age Digestion: You may experience changes in digestion as you age, which can affect nutrient absorption. Machowsky notes iron and vitamin B12 as nutrients that may warrant attention and recommends testing for possible deficiencies at your annual physical.Hydration: Your total body water and your thirst drive can decrease with age, making it easier to become dehydrated without even noticing that you’re thirsty. Be sure to hydrate regularly throughout the day and around workouts.Metabolism: As your metabolism slows with age, you might have to be more intentional about the timing of your meals and initiating secondary hunger, Butler explains. If your hunger cues become less noticeable, scheduling regular meals and snacks can help you consume enough to support your training.Weight Loss and Weight ManagementIf weight loss or weight management is one of your goals, you don’t necessarily need to begin by counting macros. Small, sustainable changes can add up over time. Start by asking:Are you eating out frequently? Try preparing more meals at home. Do you regularly consume processed snacks? Swap packaged standbys for whole food alternatives.Do you drink a lot of sweetened beverages? Start by replacing them with water or unsweetened tea. If you’re concerned about underfueling as you progress through your weight loss journey, ask yourself the following questions and answer them honestly:Do you have enough energy throughout the day and during workouts? Are you frequently sick or injured? Are you experiencing persistent or excessive soreness? Is your performance at least stable or improving? Your answers to these questions may signal that you aren’t fueling enough and should not be treated as a normal part of weight loss. For more guidance, check out Runner’s World’s Running for Weight Loss program.Got questions about performance nutrition?Fueling can be the difference between a run that feels strong and one that falls apart.Through conversations with leading sports dietitians, nutrition experts, and coaches, the Runner’s World Guide to Nutrition and Fueling turns the science of sports nutrition into practical, runner-friendly strategies for everyday training and racing. Available exclusively to Runner’s World+ members on September 10!Kristen Wagner joined the Runner’s World and Bicycling team as a senior health & fitness editor in November 2024 with a decade of magazine editorial experience. In her role, she prioritizes content that supports the brands’ marquee video programs and works closely with members on exclusive Train With opportunities. Since joining the team, Kristen has caught the bug for running! She completed her first 5K and looks forward to accomplishing longer race distances. Passionate about all things wellness, Kristen enjoys Pilates and long walks with her dog, Koda. LinkedIn