Published October 23, 2025 07:56AM
With America’s current obsession over protein (high-protein donuts are a sign we have gone totally protein crazy), it’s easy to see why endurance athletes are rethinking their post-workout fuel. Now, we are being told that optimal recovery only occurs when serving up plenty of protein post–sweat session. Protein powders have become an after-workout hero.
Yes, it’s important to take in sufficient amounts of this macro to help your muscles bounce back faster and better, but, as a newly released study suggests, if you overlook carbs, your recovery can take a significant hit. And you likely need more carbs than you think.
The latest research on carbs for recovery
Research published in The Journal of Physiology studied 12 well-trained male cyclists who participated in bouts of vigorous muscle and liver glycogen–depleting exercise. Afterward, they were provided with 10 grams of carbohydrate per kilogram of body weight in the form of sugary liquid and carb-dense meals over a 12-hour recovery period (1.2 grams per kilogram body weight per hour during the first six hours).
The study determined that muscle glycogen levels remained noticeably below pre-exercise levels when tested six and 12 hours following the workout (55% of pre-exercise at 6 hours and 69% at 12 hours).
In contrast to muscle, liver glycogen levels, assessed using a sophisticated magnetic resonance spectroscopy, were fully restocked within six hours post-workout on a cycle ergometer when the subjects were fed carbs, in the form of a sucrose solution, at a rate of 1.2 grams per kilogram of body weight per hour.
In other words, and not surprisingly, in the absence of carbohydrate intake when the athletes fasted for 12 hours post-exercise, muscle and liver glycogen concentrations remained unchanged and significantly drained during recovery. After a tough workout is not the time to practice intermittent fasting.
The upshot is that even at fairly high intakes of carbs, for instance 725 grams for a 160-pound athlete, muscle glycogen may not be fully replenished after several hours of recovery. This delayed muscle glycogen replenishment can be especially problematic for athletes who are training or competing for multiple days where the recovery window is shorter.
Perhaps if glycogen levels were assessed over a long period of time, say 24 hours post-workout, with continued high-carb intake, then muscle glycogen may get up to where it should be. Indeed, the study authors believe this would be the case.
It’s also worth noting that the athletes in this study were not provided supplemental nutrition during the cycling tests, which would have likely decreased the degree of glycogen depletion and made it easier to get restocked post-workout.
What we should glean from these findings is the critical importance of high post-training carbohydrate intake and, if possible, providing sufficient amounts of recovery time (i.e., more than12 hours) to allow for a greater chance to optimize muscle glycogen restoration following exhaustive exercise.
Why to go big on post-workout carbs
Hopefully, by now, you know that carbohydrates are a vital substrate source for muscular energy production during exercise. As exercise intensity increases, the reliance on muscle and liver glycogen, two forms of carbohydrate storage, for energy production swings upward. Consequently, prolonged exhaustive exercise like a triathlon leads to substantial depletion of these glycogen stores.
It’s been shown that 90–120 minutes of intense exercise can deplete glycogen stores by up to 60% in both places. And the depletion of glycogen stores, along with drops in blood glucose levels (hypoglycemia), are related to increased feelings of fatigue and reduced endurance exercise capacity.
Exercise with glycogen levels at 75% of what they could be, and it’s likely you’ll hit the wall sooner than if you start at 100%, especially if you also fail to take in enough fuel during the workout.
For this reason, athletes should be working to replenish their glycogen stores following exercise through sufficient carb intake so that they are starting later exercise sessions with an optimal amount of this substrate. With carb intake, plasma glucose, lactate, and insulin concentrations increase post-workout, providing the necessary substrates and hormonal environment to support glycogen formation.
This replenishment is particularly important when performance needs to be regained in less than 24 hours. That is why they say multi-stage cycling events like the Tour de France are as much of an eating event as a cycling event.
How many carbs triathletes need
Glycogen replenishment depends on carbohydrate intake. To support optimal repletion, current guidelines recommend consuming carbohydrates at a rate of 1.2 grams per kilogram of body weight per hour during the initial hours of post-exercise recovery. Do this, and you should end up with, or get closer to, fully restocked muscle glycogen helping you to perform like a champ.
But, as the aforementioned study suggests, even this amount may not be enough to replenish all of your muscle glycogen within 12 hours after a bout of vigorous exercise. So if you are going to be going hard again soon, then you may want to consider bumping the carb intake even higher to levels greater than the 10 grams per kilogram of body mass used in the study. Yes, that is a lot of bread, rice, and pasta. In short, the shorter your recovery window, the more carbs you need to stuff in.
Here are some general carbohydrate fueling guidelines to optimize recovery:
Less than 2 hours of training: Consume 1.2 grams of carbs per kilo of body weight each hour for the first two hours after activity. That is 70 to 80 grams each hour for a 150-pound athlete.
2-plus hours of training: Consume 1.2 grams of carbs per kilo of body weight each hour for the first four hours after activity.
4-plus hours of training: Consume 1.2 grams of carbs per kilo of body weight each hour for the first six hours after activity.
To reach these numbers, it can be easier to obtain some of the carbs from simple forms like sports drinks or from fruits that have been blended into smoothies. Follow this up by consuming meals and snacks that contain additional carbs, both in simple and complex forms.
Overall, the goal for competitive athletes is to get to at least 10 grams of carbs per kilo of body weight during the crucial 12-hour recovery period, going higher if your recovery time is short. To reach these lofty carb amounts, you need to be consistently eating carbs during the recovery period. In other words, don’t think you can inhale a big bowl of pasta an hour after your run and then think you are done.
Need to go carb-manic? Here’s how much of the macro you’ll get in servings of various carb-dense foods.
2 cups cooked spaghetti: 74 grams
2 slices whole-grain bread: 24 grams
1 scoop Tailwind Endurance Fuel: 25 grams
2 cups oatmeal: 58 grams
1 large banana: 31 grams
1 medium potato: 33 grams
1 1/2 cups cooked white rice: 67 grams
2 tablespoons honey: 34 grams
1 bagel: 48 grams
1 cup strawberries: 11 grams
1 cup cooked quinoa: 39 grams
2 tablespoons fruit jam: 27 grams
1 cup black beans: 41 grams
3 medjool dates: 54 grams
Apple pie smoothie recipe for recovery carbs
(Photo: Getty Images)
Here is a seasonally inspired blender drink that offers a winning mix of recovery carbs and protein to help you bounce back faster. Plus, it tastes like dessert.
Ingredients:
1 cup milk
3/4 cup plain Greek yogurt
1 tablespoon maple syrup
1 scoop plain or vanilla protein powder
1 medium apple, chopped
2 pitted medjool dates
2 tablespoons almond butter
1/2 teaspoon vanilla extract
1/4 teaspoon cinnamon
1/4 teaspoon ginger powder
1/8 teaspoon nutmeg
1/2 cup ice cubes
Place all ingredients in a blender container in the order listed and blend until smooth.