It is Sunday story time so let me tell you about two athletes.

Same training.

Same total carbs.

Same 24-hour glycogen levels.

One of them performs 30% worse the next day.

Can you guess why?

This is where the ultra hardcore science only crowd -who rarely ever train a single person = break out the pubmed studies and declare from the mountain"

“Total daily intake of carbs is all that matters.”

...but is that still true today? Grab your propeller head and hold your glute max with both hands as we explore brand new data here.

A few months ago, Fuchs et al. (2025) took 12 well-trained cyclists — VO₂max around 67 ml/kg/min.
​
Real engines. Not weekend race walkers chasing a donut.

They drained them with brutal training.

Then they fed them 10 grams per kilogram of carbohydrate.

That’s not a banana and a prayer.

That’s war-level carb intake. For a 220 lb mammal (100 kg) that is 10 grams X 100 kg = 1,000 gm of carbZ.

Yes, that is a metric piss ton.

They used ¹³C MRS at 7 Tesla to measure glycogen. Which means they weren’t guessing. They were literally watching glycogen refill in real time.

Here’s what happened:

Liver glycogen?

Boom. Refilled in about 6 hours.

Muscle glycogen?

Still sitting at ~69% after 12 hours.

Let that sink in to the pubmed ninjas brainZ.

This means that you can crush carbs all evening…

…and still wake up under-fueled at the muscle level.

Think of your liver as a checking account.

And muscle is a more slow-moving savings bond.

And if you’re training again inside 24 hours?

That difference in glycogen matters.

Now let’s twist the knife.

Díaz-Lara et al. (2024) did something deceptively simple.

Recreationally active men. Hard interval session.

Both groups consumed ~7 g/kg/day carbs, so our mythical 220 lb mammal would hoover up 700 grams of carbZ. No small amount.

Same total intake between groups.

Only difference?

One group ate carbs immediately post.

The other waited three hours.

That’s it.

Three.

Hours.

At 24 hours, muscle glycogen was similar.

If you stop there, you declare victory for Team “Timing Doesn’t Matter BroZ”

...But performance doesn’t care about your narrative.

The delayed group showed:

• ~30% lower next-day exercise capacity
• Higher RPE
• Worse repeat high-intensity output

Same carbZ.

Same glycogen actually .

Less performance though.

So what happened?

Immediately post-training, your muscle is in a rare physiological state:

GLUT4 translocation is elevated.
Glycogen synthase is activated.
Insulin sensitivity is high.
Glucose uptake is accelerated.

This is not magic.

It’s kinetics.

You delay carbs, you miss peak synthesis rates.

Even if total glycogen “catches up” by 24 hours, the restoration curve was slower.

And when you train again before that curve fully stabilizes?

You pay for it with crap-tastic performance.

Performance is about rate of recovery, not just endpoint numbers.

That’s the part the Instagram macros only GooRoo crowd doesn’t model.

Now here’s the uncomfortable part.

If you lift twice a week and don’t care about output?

You can ignore this.

If you:

Train twice a day
Lift at night and sprint in the morning
Compete
Care about repeat power
Care about high-output work capacity

Then carb timing isn’t bro science.

It’s leverage.

You don’t need superstition.

You need real applied physiology.
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​Do This Part

Here is what to do if you want to crank performance and remember that better performance lifting day in and day out leads to mo' muscle.

If recovery time is under 24 hours:

Eat carbs immediately post-training.

Not “whenever you get home.”

As soon as possible post training.

Because muscle glycogen refills slowly.

Early refueling improves next-day output.

And waiting three hours can cost you ~30% capacity.

And if you’re serious about performance?

Thirty percent isn’t noise.

It’s the difference between adapting and stalling - for eating the same amount of carbZ.

Too many "out there" roaming the purple halls of PF obsess over supplements promoted by biohacking GooRoos who would sell their mom at the right price.

Few respect substrate kinetics and actual physiology.

That’s why most people plateau.

And the ones who understand fuel timing?

They quietly outwork everyone else.

Applied physiology driven by violent consistency.

Much love,

Dr Mike
1) Listen to one of my podcasts totally free HERE.

2) Read one of the tons of free articles I have on my site HERE.

3) Book a private 1 hour virtual call to ask me any questions. Cost is $250 and you can email Jodie HERE

References

Fuchs, C. J., Gonzalez, J. T., Beelen, M., Cermak, N. M., Smith, F. E., Thelwall, P. E., Taylor, R., Trenell, M. I., & van Loon, L. J. C. (2025). Carbohydrate intake of 10 g/kg body mass rapidly replenishes liver but not muscle glycogen contents during 12 h of post-exercise recovery in well-trained cyclists. The Journal of Physiology.

Díaz-Lara, F. J., Morales-Alamo, D., Calbet, J. A. L., et al. (2024). Delaying post-exercise carbohydrate intake impairs next-day exercise capacity but not muscle glycogen or molecular responses in recreationally active men. Acta Physiologica.

_____________________

Mike T Nelson CISSN, CSCS, MSME, PhD
Associate Professor, Carrick Institute
Owner, Extreme Human Performance, LLC
Editorial Board Member, STRONG Fitness Mag

Mike T Nelson is a PhD and not a physician or registered dietitian. The contents of this email should not be taken as medical advice. It is not intended to diagnose, treat, cure, or prevent any health problem - nor is it intended to replace the advice of a physician. Always consult your physician or qualified health professional on any matters regarding your health.

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