Fiber is a form of carbohydrate that is not digestible by the human digestive system. Instead of being absorbed, fiber is broken down by gut bacteria in the colon, and then those breakdown products - called “short chain fatty acids” or SCFA - are absorbed by the body.

These SCFAs are a major reason why fiber and healthy gut bacteria are so important for health. They have numerous benefits think immune and antioxidant system support.

Unlike the regular fats in what you eat, which are absorbed relatively quickly in your small intestine, SCFAs from fiber are absorbed many hours after ingestion in the large intestine.

Since SCFAs are also a type of healthy fat, when these are absorbed, your muscles can use them for energy production. So, since fiber takes hours to get through your digestive tract, it can be considered a form of slow-release energy to fuel long days.

The SCFAs from fiber help to support healthy regulation of inflammation and serve as a delayed-release form of energy. Both are relevant reasons to support your muscle function by getting enough fiber.

Fiber helps to slow your body’s glucose response to meals with carbohydrates in them. This can help reduce the negative effect that carbs can have on metabolism, but it holds many downstream benefits. With a typical carb-heavy meal, your glucose can get into a higher-than-healthy range. Besides the negative metabolic effects, this also impairs your muscles and connective tissues by causing “advanced glycation end products.”

We’ve written some articles on the importance of keeping these low, but briefly: they irreversibly link sugar molecules to collagen molecules in your muscles and tendons. This interferes with their elasticity and compliance, making your connective tissues brittle and weak. 

Heavy exertion and too frequent exercise can put high demands on your anti-inflammatory system. When your body is using all your antioxidants to heal overworked tissues, it saps your immune system’s reserves and puts you at an increased risk for getting sick. Fiber helps reduce inflammation (by virtue of the same SCFAs), but also promotes immune health. Fiber helps by shifting your immune system away from chronic inflammation and towards a position that is more able to mount an acute immune response. So, if you’re working hard and often, the added fiber can be particularly important for your immune system. 

Similar to how fiber helps to lower glucose after a meal, fiber also binds up fats and cholesterol to help reduce cholesterol levels. Interestingly, exercise is another great way to reduce those bad cholesterol levels. With cholesterol being so important for heart health, it’s imperative to keep cholesterol in a good range in order to get the most out of your cardiovascular system. When your arteries are clogged, your heart’s ability to shuttle nutrients and oxygen throughout your body declines. With less oxygen and less nutrients getting to where you need them, you’ll definitely feel the effects of low energy levels.