This one is arriving while I'm still in Greece, so I wrote it before I left. Consider it a postcard with footnotes :)

I got a question before I left, someone asked whether she should be carb loading before her Saturday long run which is about five miles. As someone who ran for 17 years in multiple races and a marathon, this question still interests me even though I no longer run. It's a great question because the honest answer is no and the reason why is more interesting than the answer.

But first, let's start where most of us actually live, which is the gym or shorter bouts of cardio rather than the marathon course.

The other question is whether eating carbs before you lift makes you lift better. Two research teams have looked at this properly, and what they found is interesting.

A systematic review in Nutrients pulled together 49 studies on carbohydrate intake and strength performance. In the acute studies, higher carbohydrate intake did not improve performance in 13 of them. It helped in six and those six were mostly studies where the comparison group had been fasting or where the workout ran to more than 10 sets per muscle group. None of the seven short-term studies found a benefit. Across the longer-term studies, 15 out of 17 found carbohydrate intake made no difference to how performance changed over time. There was no dose-response effect, meaning more carbs did not mean more benefit.

Their conclusion was that carbohydrate intake on its own is unlikely to matter for strength training performance when you're already fed and your session is up to about 10 sets per muscle group. This is counter to a lot of conventional advice regarding fueling preworkout.

A meta-analysis in Sports Medicine looked at overlapping ground and came out somewhat warmer on it. Pooling 21 studies and 226 participants, it did find a benefit of carbohydrate before training on total session volume. But the benefit only showed up when sessions ran longer than 45 minutes and when people had been fasting for eight hours or more. It was moderated by how many maximal effort sets you did and not by the dose of carbohydrate or the load lifted.

So the two teams emphasize different things, which is normal. But read together, they agree on the part that matters for you. If you're reasonably fed and your session is under 45 minutes and nowhere near 10 hard sets per muscle group, a pre-workout carb is not what's standing between you and progress.

Here's my favorite detail in any of it. One study found that a carbohydrate meal improved performance compared to drinking water, but it did not improve performance compared to a sensory-matched placebo breakfast. Meaning: something that tasted and felt like breakfast worked just as well as the real thing. A good chunk of what people feel from their pre-workout ritual may be the ritual.

Which brings me back to the five mile run and what we more traditionally think of as carb loading.

Endurance sports carb loading is real and it's a different animal. It exists to saturate muscle glycogen before prolonged endurance events, meaning races lasting over 90 minutes. A 2025 trial in the European Journal of Applied Physiology had eleven people eat 10 grams of carbohydrate per kilogram of body weight per day for three days. For a 150 pound woman that's about 680 grams of carbohydrate a day, on top of everything else. Muscle glycogen rose about 23 percent. Eleven people is a small study, so hold it loosely.

Two things in that study are worth attention though. The participants did no depleting exercise beforehand, which means the old exhaust-yourself-first phase isn't required the way it used to be taught. And body mass, fat free mass and body water all rose measurably. Glycogen is stored with water, so real loading moves the scale. It isn't fat. It's your muscles doing what you asked...storing carbs for later use.

Now the interesting part, a systematic review and meta-analysis in Frontiers in Physiology pooled 30 glycogen loading studies going back to 1966. It confirmed the effect is real. But, across those 30 studies there were 319 participants: 271 men and only 48 women.

So when someone quotes you a carb number, they are, overwhelmingly, quoting research done on men.

When researchers did look at women specifically, they found something different. In a small randomized trial in the Journal of Applied Physiology, six well-trained men and six well-trained women raised their carbohydrate intake. The men increased muscle glycogen. The women didn't, until they also increased their total energy intake by roughly a third.

It's twelve people, so I'm not going to put too much weight on it. But it points at something I see constantly in women. The limiting factor usually isn't carb timing or carb percentage. It's UNDEReating, esepcially in women who are very active.

So where does that leave you?

If you lift for 45 minutes or an hour in a fed state, eat what helps you feel good and stop worrying about it. If you train first thing after a genuine overnight fast or you're doing long high-volume sessions, having something beforehand is reasonable and the research supports it. If you're racing past 90 minutes, carb loading is worth doing And if you're a woman who suspects she's undereating, more food overall is key for better performance, not just carbohydrates.

That last one is what I'd actually check on. My High Protein Kitchen meal plan exists for exactly that problem. Every recipe has the protein counted, the October plan just landed on Wednesday, and it takes the daily guesswork out of eating enough. If you missed it, here is the free version and you can check out the full meal plan here.

Hit reply and tell me what you do before you train and whether you've ever questioned it. I read every response, though I'm a few time zones away this week so I may be slower than usual getting back to you.

Have a great weekend!

P.S. I'm home on Monday. Greece was Milos, Sifnos and Mykonos, and I stayed at a few places I'd partnered with, so I'll be writing those up honestly over the next few weeks. Plus the results of the biomarker panel I ran before I left. October is going to be a busy month around here!