Fiber for Fitness: How to Achieve Better Performance 💪🏼

For most people, summer time means beach trips, vacation, and free time (finally!)… but for athletes, it means fitness packets, team training, and tournaments. 


Before you jump to the conclusion that this post isn’t for you because you “aren’t an athlete,” think again, my friend! Whether you are an active exerciser or not, there is still something to learn from this post. We promise! 

We’ve mentioned in previous posts that fiber has a lot of benefits, so today we are going to tell you how fiber benefits  your physical fitness, when the optimal time for fiber intake is, and when to lay off of it. Yes, too much fiber can hurt you, just like anything else, but knowing when you’ve had too much and when you haven’t had enough is another challenge we want to help you overcome. 

Let’s begin…

Why is fiber important for athletes?

Like everyone else in the world, athletes have a hard time establishing and maintaining healthy eating habits, too. You may workout 10+ hours a week, but to stay healthy, you have to consider everything you eat. Athletes tend to have a high intake of protein and carbs, but when it comes to fiber, they fall short just like the rest of us. 

Reminder: it is recommended that the daily intake of fiber is 20-35 grams for men and women regardless of physical activity. 

With the right intake of fiber, athletes and non-athletes alike can have better appetite control, improved insulin and blood sugar levels, and a stronger immune system. These health benefits are crucial to improving athletic performance and overall physical fitness.

Break it down a little further… How does fiber help exactly?

Appetite Control

Do you find yourself hungry throughout the day and eating small snacks in addition to the meals you make? Do you eat and not feel satisfied? Or eat a meal you were craving, but still feel hungry afterwards?

A high intake of fiber fixes this problem! Let’s learn how. Fiber helps control your appetite by absorbing water. Ever notice that after eating apples or broccoli that you are less hungry than when you eat a pint of ice cream? That’s because apples and broccoli are amongst the many foods that are rich in fiber. They absorb water and create a gel-like substance in the gastrointestinal tract that takes up more space in your stomach. 

So when you eat high fiber foods, your stomach is only concerned with breaking down the fiber because it’s taking up all the space in your stomach! Since fiber slows down digestion, you’re full for a longer period of time, which means you snack less, which makes it easier to eat clean. And for athletes, bodybuilders, and people trying to lose weight, this is a perfect solution to keep them disciplined in eating healthy.  

Insulin Control

A high-fiber meal has several positive effects on your digestion in addition to making you feel full faster and for a longer period of time. When you combine a high-fiber meal with protein, it can help distribute the release of nutrients like glucose into your bloodstream. That’s great for your body composition regardless of whether you are trying to bulk up, slim down, or maintain the physique you have! Regulating blood sugar levels and increasing insulin sensitivity can help prevent diabetes, obesity, and heart disease. 

Exercising and a balanced diet go hand-in-hand in preventing obesity-related diseases and other illnesses. An active lifestyle does not mean that you are automatically immune to sickness which is why it is so important to pay attention to what you’re putting into your body.

Immune System Boost

We saved the best or last! 

When you eat fiber, you’re not just feeding yourself — you’re also feeding the “good” bacteria in your gut. This bacteria helps to reduce inflammation and enhance immune function. Now, if you eat the right amount of fiber on a daily basis, guess what that means for your immune system? That’s right, you’re on your way to having a healthier body! 

A stronger immune system means you’ll get sick less often, which means you get to spend more time training and less time missing life’s most important events. It also helps you to recover faster from training by producing the necessary cells to support tissue repair. When you workout, you’re creating microscopic tears in your muscle fibers, which is why you may feel sore afterward. Your muscle is rebuilding the tissue it tore, but also making it stronger and a strong immune system will produce an abundance of cells to help regenerate your muscle and recover faster.💪🏼💪🏼💪🏼

Pretty cool, huh? 😎

So, when should I eat fiber-rich meals and when should I not?  

“Understanding the role that fiber plays in energy availability and digestion can help athletes further fine tune their nutrition strategy for training and race day. When you’re planning carbohydrate, protein and fat intake, be sure to consider fiber as part of a well-rounded and healthy approach to your training diet.”

Quick Recap: One of the great benefits of having a consistent intake of the recommended amount of fiber is that it helps you to control your appetite, which is great because it makes it harder to snack in between meals.

But here’s the kicker: too much fiber can also cause gastrointestinal distress because it slows down the digestion process. 

Too much fiber intake close to a workout can actually cause some issues both while you workout and after. Thankfully, there is a simple solution to this! Eat fiber foods a minimum of two hours prior to your workout. 

But a couple of days before a high intensity event, like on race day or game day, decrease your fiber intake. Why? Decreasing your fiber intake on the days leading up to an event can decrease the chances of having gastrointestinal distress during that event, and the last thing anyone wants is a gas cramp.  

Based on the article written by Pamela Nisevich, a dietician who specializes in sports, athletes should eat fiber rich meals on rest days or after workouts. Nisevich suggests athletes also gradually increase their fiber intake because it requires a lot of water and could lead to dehydration and constipation. 

So if you, reader, start to increase your fiber intake, DRINK LOTS OF WATER! You want to make sure that your body is getting all the nutrients it needs to work efficiently and successfully. 


We may know the facts about fiber from research and personal experience, but we aren’t doctors or nutritionists. Ask your doctor, dietician, or nutritionist about any changes you make to your diet or what you should eat to improve your health. 


DO increase your intake of fiber on rest days and after workouts with your protein meals, so your muscles can recover faster, your stomach can efficiently distribute the nutrients to your body to give it the energy it needs, and to help balance your metabolism. 

DON’T increase your fiber intake a couple of days before and on the day of the big event because it can cause bloatedness and probably negatively impact your performance. You should still eat fiber foods like an apple, but don’t go crazy. 

DEFINITELY talk to you a nutritionist or dietician about what foods and behaviors are best for you to improve your health. 

Now that you know how fiber can help you, you can make better decisions on what to include in your diet and when. If you still don’t know what to eat, we made a list of foods you can eat and make that will provide you with protein and fiber:

Foods high in Protein and Fiber

Food (serving) Protein (g) Fiber (g)
Almonds (1 oz.) 6 3.4
Oats (1 cup) 11 16.5
Broccoli (1 cup) 3 2.4
Quinoa (1 cup) 8 5.2
Lentils (1 cup) 18 15.6
Pumpkin Seeds
(1 oz.)
9 9.6
Brussels Sprouts
(1 cup)
4 4
Kidney Beans (100g) 24 6.4
Chickpeas (100g) 19 8.3
Chia Seeds (100g) 11 34.4
Baked Potato:      
S  (~ 138g)     
M (~ 173g)     
L  (~ 299g)


Brown Rice (1 cup) 5 195
Visit UCSF Health to learn more.

On-the-Go Solutions

Add to your protein shakes, smoothies, water bottles, etc! Quick AND simple


Increasing Fiber Intake

Fiber’s Role in Muscle Building

Fiber Intake Guidelines for Endurance Athletes

Digestive Health for Active People


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