Correct Way to Carb Load and Common Mistakes

Carbohydrate loading entails changing your eating and exercise patterns for 1 to 3 days to raise the amount of carbs stored in your body. It can enhance athletic performance for certain events, but it isn’t necessary for every kind of activity.

Carbohydrates serve as one of the body’s main energy sources. Within the body, carbs are stored as glycogen, which is primarily located in the liver and skeletal muscles.

During moderate to high intensity exercise, your body relies on these glycogen reserves as its chief fuel.

However, glycogen storage capacity is limited, and these stores are progressively used up as you exercise.

Carb loading is a dietary approach intended to elevate your body’s glycogen beyond typical levels. It consists of consuming more carbohydrates than usual while reducing training for a short period.

This strategy can be useful for sustained, high-intensity exercise lasting more than 60 minutes, but for shorter or lower-intensity sessions it may not offer a benefit.

Read on to understand how carb loading functions, the different methods, common pitfalls, and which foods to choose.

How carb loading works

Carb loading focuses on increasing carbohydrate intake and boosting glycogen stores for 1 to 3 days before a prolonged or intense event that’s likely to drain your glycogen.

This typically involves upping carbohydrate consumption while tapering exercise volume and intensity.

Generally, specialists advise consuming about 10 grams (g) per kilogram (kg) of body weight (around 4.5 g per pound) of carbs daily. So, a 70 kg (154 lb) individual would aim for roughly 700 g of carbs each day.

Older guidance used a percentage-based approach where 60% to 70% of total calories came from carbohydrates. That method is less favored now, since calorie needs vary greatly between people.

Note that increasing carbs doesn’t necessarily mean increasing total calories; as you raise carb intake you’ll generally reduce protein and fat intake to keep calories stable.

Who benefits from carb loading?

Experts indicate carb loading is most likely to improve outcomes for specific types and lengths of exercise.

It’s most relevant when the activity causes substantial depletion of muscle glycogen, such as high-intensity endurance efforts like cycling, running, or team sports like soccer.

In these activities, fatigue can arise when glycogen stores fall too low. Research suggests carb loading may extend the availability of energy, allowing you to perform longer before fatigue sets in.

An earlier 1997 study showed carb loading enhanced performance for activities lasting over 90 minutes.

Carb loading tends to help during prolonged, strenuous exercise, but it’s unlikely to be helpful for brief or lower-intensity training such as typical resistance workouts, because those rely more on fat as the main fuel.

Carb loading approaches

Several carb loading approaches exist, yet they all center on increasing carbohydrate intake and temporarily cutting back on training.

Below are the two common protocols:

Classic 6-day method

The traditional 6-day protocol, devised in the 1960s, aims to deplete glycogen over the first 3 days, then replenish and saturate stores with a high-carb diet for the following 3 days.

• Days 1–3: A low-carb regimen—about 5% to 15% of calories or roughly 100 g from carbs—paired with high-intensity training.
• Days 4–6: A high-carb plan—over 70% of calories or about 500 g of carbs per day—paired with low-intensity exercise.

While it was once thought the depletion phase boosted subsequent glycogen supercompensation, 2017 evidence suggests the depletion step may not be essential.

Short 2–3 day method

Current recommendations often favor a carb-loading window of about 36 to 48 hours before the event. This commonly equates to consuming 10–12 g per kg (4.5–5.5 g per pound) of body weight in carbohydrates.

Some athletes also follow a low-residue eating plan for around 3 days before competition to lower the chance of gastrointestinal issues. This limits high-fiber foods that can leave undigested residue in the gut.

Frequent mistakes and how to avoid them

Before beginning a carb loading regimen, be mindful of several typical errors.

Carb loading when it’s unnecessary

Evidence indicates carb loading is useful for extended, high-intensity activities lasting beyond about 60 minutes, such as endurance races.

For shorter or less intense efforts, carb loading often won’t yield benefits.

For example, a 2022 review concluded carb loading is generally not advantageous for typical weightlifting, unless training at very high volumes—more than 10 sets per muscle group in a single workout.

Carb loading unnecessarily may also lead to an excess calorie intake.

Consider the nature of your activity and whether carb loading is likely to help. If you’re unsure, consult a registered dietitian, coach, or healthcare provider to weigh the benefits and drawbacks.

Consuming the wrong carb amount

Failing to eat enough carbs during a planned loading period can impair performance, while overdoing carbs can cause excess calories, weight gain, or diet disruption.

To estimate how many carbs to consume, track your usual food intake for several days with a food log or app and use nutrition labels to calculate grams of carbohydrates.

Then divide your daily carb grams by your body weight to compare your current intake to carb loading guidelines.

For instance, if you weigh 70 kg (154 lb) and normally consume 300 g of carbs daily, that’s about 4.2 g per kg (1.9 g per lb).

Experts advise roughly 10 g of carbs per kg (4.5 g per lb) per day for loading, meaning you’d need to more than double your typical carb intake in this example.

Eating too much fat

Dietary fat is essential within a balanced eating plan.

Although further research is necessary to clarify fat’s role in carb loading, limiting fat during the loading phase can help avoid excess calories and feelings of sluggishness.

That said, a study found consuming a high-fat meal 3.5 hours before an event after a carb-loading phase may actually aid glycogen usage during the event.

A registered dietitian can help you decide an appropriate fat intake during loading.

Eating too much fiber

Some people report that high-fiber foods during carb loading can increase the risk of gastrointestinal upset—bloating, stomach discomfort, and water retention—during competition.

During carb loading, it may be preferable to select refined grains like white bread or pasta instead of whole-wheat varieties.

Not tapering exercise enough

Failing to reduce or “taper” training while increasing carbs can limit how much your glycogen stores can rise.

A trainer or registered dietitian can recommend the ideal mix of exercise type, duration, and intensity for the loading period.

Foods to choose and limit during carb loading

To reach recommended carbohydrate targets, prioritize foods that are carbohydrate-dense, low in fat, and moderate in fiber.

The list below highlights options to favor and to avoid during your carb-loading phase:

Foods to eat
• low fiber cereals
• 100% fruit juice
• white noodles with marinara sauce
• white bread
• fruit jelly
• white rice
• fruit smoothies
• skinned white potatoes
• applesauce
• pretzels
• bananas
• oranges
• watermelon
• white flour used in cooking
• sherbet or popsicles
• sports drinks
• low fat energy bars

Foods to limit
• creamy sauces
• muffins
• chips
• cookies
• pizza
• brownies
• ice cream
• pastries
• french fries
• donuts
• high fiber energy bars
• beans
• lentils
• split peas
• whole wheat products
• bran flakes
• oatmeal
• raspberries
• artichoke
• green peas
• chickpeas
• chia seeds
• broccoli

It’s also important to keep consuming protein and healthy fats to support muscle health. Emphasize lean protein sources such as fish, lean cuts of meat or poultry, and low-fat dairy.

Finally, stick to foods you enjoy and are accustomed to eating. For practical meal examples and timing when planning your loading phase, you may find a sample day and tips helpful — see this carb loading guide for an example plan.

Bottom line

Carb loading is a dietary tactic to raise glycogen stores, which can boost performance in high-intensity activities lasting longer than about 60 minutes.

A typical loading phase spans 1 to 3 days and involves eating roughly 10 g of carbs per kg (4.5 g per lb) of body weight per day.

This approach may not be necessary for recreational exercisers or those not competing in long-duration events.

If you’re uncertain whether carb loading fits your needs, consult a healthcare provider, registered dietitian, or coach who can create the best plan to support your health and performance goals. For guidance on meal timing around training, see advice on when to eat before workout and when to eat after workout.