Fiber and fitness: How they work together

How fiber keeps you fit

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Though you may think of protein as the No. 1 fitness nutrient (bodybuilders eat a ton of protein, right?), fiber-rich foods also rank high as fitness fuel. Fiber is essential for athletes and recreational exercisers to meet their workout needs, so maybe your grandma isn't off the mark when she says fiber keeps her regular. Fiber is crucial for your health as well as your fitness. Here’s how fiber and fitness work together.

Fiber-rich foods fuel your muscles

Fiber in and of itself does not deliver the fuel your muscles require to get you through grueling (or even lightweight) workouts, but this super-nutrient comes packaged in complex carbohydrate-rich foods that give your body energy to move. This means you can't live on fiber supplements alone; you need real foods high in fiber, such as whole fruits and vegetables as well as whole-grain breads, pastas and cereals, quinoa, rice, beans and nuts.

Fiber does keep you regular

When you're "all plugged up," exercise in any form feels uncomfortable. Fiber helps move food through your intestines by absorbing water from your colon and softening your stools. On the flip side, trying to run when you've got "the runs" is no fun, either. Fiber also helps put a stop to diarrhea by absorbing liquid in and firming up your stool.

Fiber keeps your weight down

If you've been pregnant or have carried a few too many pounds, you are familiar with how extra weight can make even the easiest of workouts uncomfortable. Fiber-rich foods fill you up and stabilize your blood sugar levels, keeping you full longer so you are less likely to overeat. In addition, many high-fiber foods, such as fruits, veggies and whole grains, are low in calories, which also aids in losing weight and maintaining weight loss.

Fiber is good for your ticker

Every time you exercise, your heart pumps increased amounts of blood through your body to oxygenate your muscles. The stronger your heart, the harder and longer you can exercise. Exercise inherently strengthens your heart, but your diet also plays a role in heart health. Diets high in fiber, particularly from whole grains, may reduce your risk of dying from heart disease. Fiber-rich foods, which include fruits, vegetables, whole grains, beans, nuts and seeds, have been shown to lower blood cholesterol levels and improve heart health. This means you can't expect exercise alone to keep you from having a heart attack or stroke. Do your heart a favor and eat more fiber.

How much fiber do you need?

Health experts suggest 20 to 30 grams of fiber per day for optimal health. The National Fiber Council raises the bar even higher, recommending 32 grams of fiber per day. If your diet has been low in fiber (most Americans get about half of the recommended daily intake), don't go out and overdo on fiber-rich foods; that can result in bloating and digestive upset. Start by swapping out your white bread with whole-wheat bread (at least 3 grams of fiber per slice), eating oatmeal instead of sugary fiber-less cereal, including fruits and vegetables at every meal, or snacking on a handful of nuts instead of chips. Aim to eat one more fiber-rich meal a week to allow your digestive system to adjust. Make sure you also stay well-hydrated to help fiber do its job.

So, how do fiber and fitness work together? Filling up on fiber-rich foods will fuel your body to keep you energized enough to exercise, keep your digestive system running smoothly for optimal comfort during workouts, help you maintain a healthy weight, and improve your overall health.

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Healthy eating habits for busy families
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Michele Borboa, MS is a contributing editor for, specializing in health, fitness, and lifestyle. She is also a food columnist for SheKnows and and a blogger for Miso Vegan. Michele is a health and wellness expert, personal chef, cookbook author, and freelance writer, based in Bozeman, Montana. She is also the author of the time-saving cookbook Make-Ahead Meals Made Healthy (Fair Winds Press, July 2011). You can reach her at or give her a tweet at