Hello Runner,
Welcome back to your weekly moment of endurance nutrition!
Happy Weekend!
How was the beginning of the year?
I hope you had a great New Year's Eve with friends and family.
My week was quiet, and my New Year's Eve was great! I went to a party with live music and danced all night.
I took the 31st off to rest, but I went to train every other day. I've been without my Garmin for over a week because the cable has a bad connection and is no longer charging. I'm waiting for the new cable to arrive.
I admit that it's good not to look at the metrics so much during training, but I can no longer do sprint training and other types of training. And running fast with my mobile in my hand is not my strong suit.
Today's topic may be considered a little “embarrassing” for some, but it needs to be discussed. How stools can be a runner's ally in discovering what is missing (and even excess) in their diet.
When was the last time you actually looked at your poop?
Not just a polite glance before flushing… I mean, really noticed it.
Color. Shape. Texture. Timing- everything.
I know it may seem weird, but for runners, stool is one of the most honest signals your body gives you.
And if you learn how to read it, it can quietly tell you what’s missing from your diet — and what’s holding back your performance.
What does “ideal” runner poop look like?
Picture this:
Medium brown
Smooth, sausage-shaped
Easy to pass, no pushing, no drama
Once or twice a day, fairly predictable
That’s the gold standard.
This is what a happy gut looks like.
And a happy gut?
It digests, absorbs, fuels, and recovers better.
Your stool is basically the final report of what happened inside your digestive system.
How well you:
hydrated
broke down carbs and fats
absorbed nutrients
fed your gut bacteria
All of that shows up in the toilet. Therefore, it is important to check (thoroughly) before flushing.
KEY INDICATOR
What Your Poop Can Tell You (and what to adjust)
Dry, hard, pebble-like stools?
Usually a hydration issue. Sometimes fiber, too, but hydration comes first.
If you’re running regularly and sweating a lot, “I drink when I’m thirsty” often isn’t enough.
Try this:
Drink more water during the day
Including tea, juices, milk, and flavored water can help with hydration
Consume more fruits, veggies, and whole grains
Pair fiber-rich foods with fluids (oats + water, veggies + soup)
Your gut needs water to move things along.
Very loose stools, especially after meals?
Could be:
Too much fiber too fast
Caffeine excess
Poor timing (fiber-rich foods before running)
Malabsorption issues
Imbalance in electrolytes/probiotics
Try this:
Spread fiber across the day instead of loading it all at once in a big meal
Monitor consumption of artificial sweeteners
Avoid fiber-rich foods close to training sessions, and prefer carb-rich foods.
Incorporate probiotic-rich foods
More fiber isn’t always better. Better timing is better.
Pale, greasy, or floating stools?
This can suggest fat absorption issues — your body isn’t fully digesting fats, or it can indicate a lack of necessary digestive enzymes.
Runners sometimes under-eat carbs and lean too hard on fats… or eat fats when digestion is already stressed.
Try this:
Balance meals with enough carbs (especially around training)
Adjust healthy fat intake to balance energy needs
Reduce very fatty meals late at night
Check if you’re eating too fast, chewing properly, or distracted
Remember: digestion starts in the mouth.
Very dark, very light, or oddly colored stools?
Short-term changes can come from foods (beets, spinach, supplements).
But consistently pale or very dark stools can signal:
Poor bile flow
Low micronutrient absorption
A sign of internal bleeding
Iron suppements
Try this:
Monitor iron intake levels
Make sure meals contain a mix of carbs, protein, and fats
Consult a doctor to rule out serious causes
Never guess. When in doubt, seek professional help.
Giphy
Runner, your poop is useful data.
It can help you:
spot hydration gaps
fine-tune fiber intake
improve fat and nutrient absorption
support gut health
The best part is that you don't have to spend money on a lab test to start paying attention.
Just take a VERY good look before you flush.
This week—starting today—I invite you to look at your stool until next Saturday. Just observe. If you want to keep a better track, take notes (like a journal) and make adjustments if necessary.
Product of the Week
This week's Product of the Week is the KIPRUN Soft Flask Running 250ml.
This was the first soft flask I bought, and I use it a lot.
For the price, I think the quality and durability are very good.
During the summer, I fill it with water and put it in the freezer for 30-40 minutes before going out for a run. That way, the water stays cold longer during the run.
If I wear shorts or leggings that don't have pockets to put it in, I carry it in my hand, and I don't think it weighs as much as a normal water bottle.
I highly recommend any runner to get one of these.
Track of the Week 🎧️
This week's Track of the Week is a really old rock song with a beat that's great for running.
You know those days when you drag yourself (reluctantly) out to go running? This song is perfect for those days.
I’ve chosen Song 2 by Blur
Any questions or something you would like to share, drop me an email
Wishing you a great weekend and week ahead!
Here’s to health and good runs⚡️
Ana Paula Alonso