If you’ve ever spent time with me at Next Level, you know I talk about protein—a lot. And for good reason. It’s the MVP of muscle repair, recovery, and long-term performance, especially as we get into our 40s and beyond.
But today, I want to flip the script.
Because there’s another nutrient most athletes are ignoring. One that plays a critical role in not just gut health, but also in energy, recovery, performance, body composition, and even lifespan.
And here’s the kicker: it’s a carb.
Yep—today, we’re talking about fiber. The one carbohydrate that isn’t sexy, doesn’t come in flashy packaging, but just might be the most underrated tool in your performance toolbox.
The Truth About Fiber (That Most Athletes Don’t Want to Hear)
Let’s rip the Band-Aid off: only 5% of Americans are getting enough fiber.
That means 95% of people—including athletes who should know better—are walking around fiber-deficient. And if you’re not eating enough of it, you’re leaving gains, recovery, and even your long-term health on the table.
Let’s break it down:
- Women should be getting at least 25g of fiber per day
- Men should aim for closer to 38g
- But most people? They’re barely hitting 10–15g
That’s like trying to PR your marathon off of 5K training—completely underprepared.
And if you’re following a high-protein, low-carb “performance diet” that skips out on plant foods? You’re probably even lower than that.
What Is Fiber, Really? (And Where the Heck Do You Get It?)
Here’s what most athletes miss: fiber is a carbohydrate. But it’s not digested and used for fuel like sugar or starch. Instead, it feeds your gut microbiome, supports healthy digestion, stabilizes your blood sugar, and helps clean out your system—literally.
There are two kinds:
- Soluble fiber (slows digestion, controls blood sugar, lowers cholesterol)
- Insoluble fiber (adds bulk to your stool, keeps things moving)
You need both.
And no—your post-workout protein bar probably isn’t cutting it. Most bars that claim to have fiber are either using synthetic forms or lack enough of the real stuff to make a difference.
Best Sources of Real Fiber:
- Oats
- Beans and lentils
- Berries and apples (with the skin)
- Broccoli, Brussels sprouts, carrots
- Whole grains like brown rice, quinoa, and farro
- Chia and flaxseeds
Personally? When I’m traveling or in a pinch, I keep Benefiber packets or Metamucil cookies with me. They’re not glamorous, but they work—and yes, they keep me regular when life gets chaotic.
Why Fiber Matters for Athletes, Especially Over 40
Now let’s talk why this matters for you as a runner, Hyrox athlete, or hybrid competitor.
Yes, fiber helps with digestion—but its benefits go way beyond gut health.
Fiber for Runners and Athletes: Real Benefits You’ll Feel
- Stabilizes blood sugar, helping you avoid energy crashes mid-run
- Reduces inflammation, which means less soreness and better recovery
- Improves cholesterol and heart health
- Feeds the gut microbiome, supporting nutrient absorption and immunity
- Keeps you full longer, which helps if you're dialing in your body comp
- Supports brain function and mood regulation
- Improves hormone health, especially important as we age
And here’s a stat that should stop you mid-scroll:
A massive meta-analysis of 185 studies and 58 clinical trials found that high fiber intake was associated with up to a 30% lower risk of early death, heart disease, and stroke.
Let that sink in.
This isn’t just about feeling “regular.” This is about feeling great now and stacking the odds in your favor for the long run—pun intended.
The High-Fiber Diet for Runners: A Word of Caution
Now before you go diving face-first into a bowl of lentils and kale, let me hit the brakes real quick.
More fiber is good—but only if you add it gradually.
If your fiber intake has been low, trying to double it overnight is a fast track to bloating, gas, and gut misery. Your system needs time to adapt.
Pro Tips:
- Ramp up slowly: Add 5g per day over a week or two
- Hydrate like it’s your job: Water helps fiber do its job
- Listen to your gut: Literally. Pay attention to how your body responds
And when it comes to race week or big event days?
Ease off the fiber. No black bean burritos the night before your 10K.
Stick to low-fiber, high-carb foods 24–48 hours pre-race:
- White rice
- Bananas
- Applesauce
- Toast
- Honey or maple syrup
Save the fiber boost for your training days and post-race meals.
Bottom Line: Fiber Is the Most Underrated Performance Tool You’re Not Using
Listen, I’ll never stop talking about the power of protein—but fiber deserves a seat at the table, too.
If you’re serious about longevity, recovery, energy, and feeling good in your body, don’t ignore the one carb that can literally save your life.
- It keeps your gut healthy
- Keeps your energy steady
- Helps regulate hormones and inflammation
- Improves your performance and your healthspan
And unlike some performance supplements out there, fiber is easy to find, affordable, and doesn’t require a prescription.
So yes—lift heavy, run fast, eat your protein… but don’t forget the fiber.
Your future self will thank you.
Your gut will definitely thank you.
And your performance? It’ll show up in the PRs you didn’t have to fight so hard for.
Need help dialing in your performance nutrition or recovery plan?
We’ve got you.
Book a visit with the team at Next Level Physio and get expert-level support—so you can keep doing what you love for decades to come.