Physical endurance is important for athletes, but it also comes into play with everyday tasks. If you've ever felt winded after doing chores or light physical activity, it could be a sign that your endurance levels are low.
"Endurance refers to the ability to sustain a given activity for a prolonged period of time," explains sports nutritionist Marie A. Spano, RD, CSCS, CSSD. "Endurance is important for athletes because those with greater endurance can train or compete for a longer period of time."
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But even if you aren't an athlete, endurance is still important. "If you are ever touring a new city by foot, enjoying a recreational tennis match or playing pickleball, greater endurance means you can stay active for a longer time," Spano says.
There are a few factors that affect your endurance, and diet is one of them. Some nutrients support endurance while others may hinder it.
Iron is an especially important nutrient when it comes to improving endurance. In the body, iron is involved in energy metabolism, oxygen transport and acid-base balance, which are especially important for endurance athletes, according to September 2014 research in Applied Physiology, Nutrition and Metabolism.
Iron supplementation has been shown to help improve endurance performance, per a February 2019 clinical trial in The Journal of Nutrition. Similarly, low iron levels have been shown to negatively affect endurance and performance time in athletes, per a December 2011 study in the International Journal of Sport Nutrition and Exercise Metabolism.
According to the experts, the best foods for endurance are sources of iron and other nutrients your body needs to stay energized. Check them out below.
The 5 Best Foods for Endurance
1. Whole Grains
Oats are a staple in many endurance athletes' diets, runners especially. That's because whole grains like oats are a source of complex carbohydrates, which are beneficial for endurance because they provide a consistent source of energy and help you feel satiated for long periods of time.
"Carbs are our number one source of energy for endurance, and they're one of my top recommendations," Spano says. "Complex carbs, in particular, are digested slowly and provide long-lasting energy. Most of the carbs you eat should come from these foods. Steel-cut oats are a great example."
A quarter-cup of steel-cut oats provides 10 percent of the daily requirement for iron as well as 5 grams of protein, per the USDA.
Other examples of whole grains include:
- Brown rice
- Whole-grain bread
- Whole-grain pasta
Beets and beetroot juice are full of nutrients that can boost endurance, which explains why some athletes supplement with beets or beet powder before a workout.
"Drinking beetroot juice has been shown to have a number of benefits for athletic performance," says strength and conditioning coach Andy Page, ASCC CSCS. "It is rich in nitrates, which raises nitric oxide levels in the blood and has been tied to improving blood oxygen-carrying capacity, improving lung function and enhancing muscle contraction force."
Dietary nitrates in beetroot juice have been shown to improve exercise endurance performance, according to an August 2018 review in the Annual Review of Nutrition.
Cooked beets also offer 7 percent of your daily iron per cup, according to the USDA.
3. High-Protein Foods
Before a workout, complex carbs provide energy, which is essential for endurance levels — but protein is important in a different way.
"Although protein is often associated with resistance training, eating enough protein after endurance exercise is equally as important," says Lily Chapman, sport and exercise nutrition coach at P3rform.
"Prolonged endurance sessions can cause big changes within the muscle — fuel stores are depleted, protein structures are damaged and waste accumulates. Protein is needed to repair and renew these structures."
Chapman recommends taking in around 0.3 grams of protein per kilogram (2.2 pounds) of body weight per meal to help support muscle building and recovery.
Some of the best sources of protein include:
- Chicken breast
- Black beans
- Ground turkey
Six ounces of lean chicken breast gives you 54.5 grams of protein and five percent of your daily iron needs, according to the USDA. For a protein source with more iron, try skirt steak — 6 ounces provide 52 percent, according to the USDA.
Like whole grains, legumes are a great source of complex carbs. They're also a great source of protein, especially for vegans and vegetarians. The carbs in legumes give you sustained energy while the protein helps build muscle mass and support recovery.
Many legumes are also especially high in iron. Large white beans, for example, are an impressive source. They offer 37 percent of your daily value and 17.4 grams of protein per cup, according to the USDA.
5. Dried Fruit
Dried fruits like figs, dates, raisins and apricots are high in iron, according to the Cleveland Clinic.
Dried fruits are another source of dietary nitrates (like those in beets), which help support endurance performance, according to a June 2020 review in Nutrients.
Just be sure that you're being mindful of your portions when snacking on dried fruit, as many varieties are high in sugar.
3 Foods to Limit for Better Endurance
If you're trying to improve your endurance, it may be best to avoid these foods right before training.
Alcohol isn't a nutrient-dense choice, but it can fit into a balanced diet in moderation. That being said, it's not the best choice right before a workout or long periods of physical activity.
Spano explains why: "While very small amounts of alcohol may have little effect, larger amounts have shown to hurt endurance performance by decreasing power output. It also has a diuretic effect. This can contribute to dehydration, which can decrease endurance, particularly in the heat."
Before an event or endurance training, Spano suggests sipping on water or sports drinks instead. Even caffeine can support endurance levels.
2. High-Fiber Foods
Fiber is an essential nutrient with many health benefits, and it's a nutrient that many Americans are lacking. Prioritizing fiber in your diet is important, maybe just not before endurance training.
"High-fiber food around endurance exercise should be considered carefully," Chapman says. "Foods high in fiber, such as vegetables, digest very slowly and sit in the digestive tract for a long time. Eating them before exercise can potentially lead to stomach upset, which will hinder your performance."
3. High-Fat Foods
Healthy fats like avocados, nuts, seeds and olive oil are beneficial for overall health and essential for good nutrition. While it's crucial to have them in your diet, they're not the ideal source of energy for endurance exercise.
"While some fat is used during exercise, it is a slow source of fuel," Spano says. "Relying mainly on dietary fat will slow you down and lower your performance." You especially want to avoid fried foods before exercise.
- The Journal of Nutrition: "Increasing Iron Status through Dietary Supplementation in Iron-Depleted, Sedentary Women Increases Endurance Performance at Both Near-Maximal and Submaximal Exercise Intensities"
- Cleveland Clinic: “How to Add Foods That Are High in Iron to Your Diet”
- MyFoodData: “Top 10 Foods Highest in Iron”
- International Journal of Sport Nutrition and Exercise Metabolism: “Impact of iron depletion without anemia on performance in trained endurance athletes at the beginning of a training season: a study of female collegiate rowers”
- MyFoodData: “Nutrition Facts for Raley’s - Steel Cut Oats”
- Annual Review of Nutrition: “Dietary Nitrate and Physical Performance”
- MyFoodData: “Nutrition Facts for Cooked Beets”
- MyFoodData: “Nutrition Facts for Cooked Large White Beans”
- MyFoodData: “Nutrition Facts for Lean Chicken Breast”
- MyFoodData: “Nutrition Facts for Skirt Steak”
- Nutrients: “Influence of Nitrate Supplementation on Endurance Cyclic Sports Performance: A Systematic Review”
- Applied Physiology, Nutrition and Metabolism: Iron and the Endurance Athlete