Hi,

Matt here. Last week, David Roche (coach, podcaster, running legend) sent an email about taking carbs before short workouts. This isn't just an email, it's a shift in how most people think about fueling, and I'm here for it. It also happens to be exactly what I've been doing for the past year, quietly, against conventional wisdom. So against conventional wisdom, I've kept my mouth shut about it. Until now. Nothing like a running legend saying it first so I don't have to be the weird one.

I asked David if I could share his email, and it's below. The idea: 20g to 40g of carbs right before your workout is a serious performance driver, during the session, and sets up your recovery. Two things before you read it.

1. It's all about timing. Not 15 minutes before. Right when you start. Don't take a gel and then wander off to stretch. Stretch, warm up, then take your gel and go. I want your heart rate climbing right after the carbs go in. Gel, then work, no gap. That's how you skip the sugar crash.

2. Why is this novel? Just yesterday I watched a so-called expert say "it's a short workout, you don't need any fuel." The logic: you've got hundreds of grams of glycogen in the tank, so you're covered. Not wrong, but having gas in the tank isn't the same as having your foot on the pedal. It's blood glucose you want pumping, and that's exactly what David's showing (and what I feel every single time I do this).

TLDR: Take a gel right before your short workout. Boost blood glucose. Crush your workout.

Over to you, David. 

In Boulder, the Niwot High School track is one of those "Only In Boulder" places. You go to this beautiful track with a mountain backdrop, and you'll usually see the marching band practicing and various classes doing slow-walking laps (maybe those are gym classes? It's a mystery!). And almost every day of the week, you'll see something else... anywhere from a couple to 15+ of the best runners in the world.

We're talking Olympians and national champions (of many different countries!) and NCAA winners and so much more. Could you imagine the same thing in basketball? LeBron and Steph Curry playing 1-on-1 at your local high school? Even after all of this time, I still have to remind myself not to ask for autographs out there.

In addition to the full fanboy experience, I try to be the Jane Goodall of track and field. I observe all of their habits. I chat with the athletes and coaches. I monitor the porta potty stops (not actually, but I bet I had you there for a second).

One of those Boulder track days was when I first understood the power of bicarb. Everyone was doing it; no one was talking about it publicly. So we tried to bring those track conversations into the public light.

And when I was Goodall'ing for the first time a few years ago, I noticed something else: many of the athletes were taking a gel between their warm-up and the workout. Sometimes the workouts were big, boss sessions that included an hour or more of intensity. But other times, the athletes were just doing some 200s before big races in Europe.

The gel intake for short sessions was SO FASCINATING. Longer distance racing has always talked about a pre-event gel. The gels before short workouts that took a few minutes were less commonly talked about, though.

It was validating, because it was something we always recommended, but weren't quite as confident about for every session. In the few years since then, our philosophy on this topic has solidified into this standard recommendation:

Before every hard workout, consume 20-40 grams of carbs after the warm-up.

Interestingly, the study that pushed us to make this a universal recommendation came from the low-carb literature. Those low-carb proponents sometimes accidentally stumble butt-backwards onto a good point!

The 2025 study is called: Carbohydrate ingestion eliminates hypoglycemia and improves endurance exercise performance in triathletes adapted to very low- and high-carbohydrate isocaloric diets. It had athletes consume 10 g/hr or 0 g/hr, and the 10 g/hr group had 22% longer time to exhaustion and eliminated exercise-induced hypoglycemia. Obviously, high-carb would be better, but a huge amount of the benefit seems to happen at really low numbers.

(Side note: a study just came out as I’m writing this that answered that exact question on very low carb versus high carb directly, finding that 10 g/hr had much worse performance outcomes, with the ideal total being 107 g/hr. So the low carb researchers were only off by an order of magnitude!)

The low-carb study likely pointed out 2 different things that are relevant to our discussion. First, the small glucose pool (i.e. blood glucose) contributes to quick energy and likely has some nervous system implications for performance. Even if an athlete has full glycogen (the body can store hundreds of grams of carbs in glycogen), short-term drops in glucose may impair performance in time-to-exhaustion tests (even though the small glucose pool only stores a few grams of carbs).

Second, there is likely a nervous system connection between the sense of carb availability and performance. That overlaps with "mouth-rinse" studies that find even using a carb mouth rinse (maybe absorbing a gram or two in the mouth, but spitting most out) improves performance relative to a placebo.

So that's the goal: make sure the small glucose pool is filled, while also harnessing any nervous system benefits from immediate carb availability. Or to put it in the old lingo: top off your carb stores before intensity, even when you’re doing very short workouts. Basically, mimic an approximation of the low-carb study protocol, but with high glycogen on board too.

Our suggestion to athletes is to do that in workouts, quality long runs, and races (after the warm-up, when blood glucose may be more depleted). It can be a very small dose (even sports drink), but there's no downside to having it be a full gel. For example, at the US 10k Champs last weekend, I coached Emily Venters, Allie Ostrander, and Amanda Vestri (1-3-4 in the race), and all of them took a Science in Sport Beta Fuel gel or similar 40g gel pre-race, after a couple mile warm-up. 

As a side note, we'll sometimes get messages from athletes who have dizziness or fatigue issues 10-20 minutes into runs. That's likely related to similar hypoglycemic effects, which some athletes are more prone to than others. Those athletes can use this approach more often too!

My favorite choices for athletes other than Beta Fuel gels:

Enervit gels (the mango flavor will blow your mind)

Precision gel

Amacx gel

You can also build your own gel pack on The Feed.

- David.