Anna Kasztenny, MSc.
Anna holds a Master’s degree in Bio-Pharmaceutical Science and Business Studies and a Bachelor of Medical Science with an Honors Specialization in Pharmacology. Alongside her academic background, she is a competitive bodybuilder and strength athlete who holds three provincial powerlifting records. As a former competitive gymnast and varsity cheerleader, she is passionate about health, performance, and evidence-based wellness.
Carb loading is one of the most misunderstood concepts in exercise nutrition. Many people hear the term and picture a massive plate of spaghetti the night before leg day. In reality, carbohydrate loading is a specific nutrition strategy designed to maximize glycogen stores before prolonged endurance events, not a blanket excuse to overeat before every gym session. Carbohydrates fuel high-intensity and long-duration exercise by supplying muscle glycogen and blood glucose, but the way you eat them, and how much you need, depends on what you're training for.
This article covers three distinct ideas: everyday carbohydrate intake that supports your normal diet and recovery, eating carbs before a standard workout, and formal carb loading for races and long events. Not every session demands a special protocol; total daily nutrition and digestive health matter far more than any single pre-workout meal.
At ALLMAX Nutrition, we build products and resources around evidence, not carb fear. Whether you lift, run, cycle, or compete in team sports, the goal is to match your fuel to your training.
What Is Carb Loading?
Carbohydrate loading is a planned, short-term increase in carbohydrate intake to maximize glycogen stores before prolonged endurance exercise. A common protocol is approximately 10–12 g/kg/day during the final 36–48 hours before an event, alongside a reduction in training volume.
Here's how it works at a basic level:
Digestion starts when you eat carbohydrate-rich foods. Your digestive system breaks them down into glucose, which enters the bloodstream.
Excess glucose is stored as glycogen in muscles and the liver for later use during exercise.
Eating a banana, toast, or a carb drink before lifting is pre-workout carbs, not technical carb loading.
Endurance athletes competing in events over 90 minutes benefit most from formal carb loading. Recreational lifters doing 45-75 minute strength workouts, casual cardio, or group classes usually do not need it.
Older 6-day depletion/loading protocols (with a multi-day depletion phase followed by aggressive refeeding) have largely been replaced. Research shows that a short period of high carbohydrate intake combined with reduced training can maximize glycogen stores without requiring a preceding carbohydrate-depletion phase [1].
Bussau et al. (2002) demonstrated that a single day at 10 g/kg of body weight daily produced near-maximum glycogen levels in trained athletes.
Why Are Carbohydrates Important for Exercise?
The chain is straightforward: carbohydrates become glucose, glucose becomes glycogen, and glycogen becomes workout fuel. Your body stores glycogen in two places, and each serves a different role.
Muscle glycogen supports moderate-to-high-intensity efforts like intervals, sprints, and heavy lifting. At intensities above roughly 60-65% of VO2 max, carbohydrate oxidation rises steeply; above 80-85% VO2 max, muscle glycogen supplies the majority of energy [2].
Liver glycogen helps maintain blood glucose during longer sessions, between meals, and overnight. Liver glycogen helps maintain blood glucose, particularly during prolonged exercise and periods without food. Adequate carbohydrate availability supports better mental focus during intense competition.
Higher glycogen reserves help delay fatigue during long events. A 2-hour run at ~70% VO2 max draws heavily on both muscle glycogen and blood glucose; glycogen depletion becomes the limiting factor toward the end. A 45-minute lifting session, by contrast, uses muscle glycogen but rarely depletes it if daily carbohydrate intake is adequate.
The body also uses fat and, to a smaller degree, amino acids for fuel. These substrates contribute more at lower intensities but cannot sustain the high rates of energy turnover required for sprinting, heavy lifting, or near-maximum efforts.
When glycogen is low, protein oxidation (muscle breakdown) can increase. Carbs are not the only fuel, but they become especially important as exercise intensity and duration climb.
Carb Loading vs. Just Eating Carbs Before a Workout
These three strategies are related but not identical. A clear distinction prevents you from overdoing it before a regular gym session or underfueling before a race.
Strategy |
Purpose |
Typical Use |
Everyday carbohydrate intake |
Maintain adequate energy and glycogen |
All active individuals |
Pre-workout carbohydrates |
Provide readily available fuel before training |
Many moderate/high-intensity workouts |
Intra-workout carbohydrates |
Maintain fuel during prolonged or demanding exercise |
Longer endurance/high-volume sessions |
Formal carb loading |
Maximize glycogen stores |
Primarily prolonged endurance events |
Everyday intake covers your total calories, supports muscle glycogen replenishment, recovery, and overall digestive health.
Pre-workout carbs are a small to moderate serving eaten 1-4 hours before training. They top off blood glucose and liver glycogen without requiring a multi-day protocol.
Intra-workout carbohydrates are most relevant during prolonged or high-intensity exercise, particularly when sessions extend beyond about 60 minutes.
Formal carb loading is a structured carb loading phase spanning 1-3 days before an endurance event, combined with reduced training, to push glycogen stores above baseline.
For most lifters and general gym-goers, focusing on regular carbohydrate intake and a smart pre-workout meal is enough. Overeating before a workout and calling it "carb loading" can upset the digestive tract and hurt exercise performance rather than help.
When Should You Eat Carbohydrates Before a Workout?
The best timing depends on your schedule, session length, and how easily you digest foods. General guidelines fall into three windows:
3-4 hours pre-workout: a larger mixed meal with carbs, lean protein, some fat, and cooked vegetables. This gives the digestive system time to process everything.
1-2 hours pre-workout: a smaller meal or snack with easy to digest carbs and lean protein sources (e.g., toast with a thin spread of nut butter, a small bowl of white rice with chicken).
30-60 minutes pre-workout: a light snack or drink using foods that are digested quickly, such as a banana, applesauce, or a carbohydrate powder mixed with water. Fat and insoluble fiber slow digestion at this point and can cause discomfort.
Practical scenarios:
A morning lifter training at 6 a.m. may not tolerate large meals. A liquid carb drink or a banana with a few sips of water can be enough.
A runner doing a 90-minute long run after work might eat smaller meals throughout the afternoon, finishing a light carb snack 60-90 minutes before heading out.
An athlete prone to gastrointestinal issues or gastroesophageal reflux disease on race day may need to finish solid food 2-3 hours out and rely on liquids closer to start time. Anyone with irritable bowel syndrome or similar conditions should consult a registered dietitian for individualized treatment options.
There's no single perfect rule. Individual experimentation with timing and food types in training is the only reliable way to find what works.
Foods That Are Digested Quickly Before a Workout
What makes something easy to digest before exercise? Low fat, low fiber, modest portion size, and gentle preparation. Cooking or peeling produce, choosing refined over whole grains, and avoiding heavy seasoning all reduce the load on your digestive tract. Foods that are digested quickly work well 30-90 minutes before training because they clear the stomach faster and reduce the chance of cramping.
Simple carbohydrate snacks: ripe bananas, applesauce cups, peeled soft fruit, low-fiber fruit juice without pulp.
Refined grains: white toast, white bread, plain bagels, rice cakes, low-fiber breakfast cereal with low-fat milk (or lactose-free milk for anyone who is lactose intolerant; lactose intolerance is common enough to plan around).
Cooked starches: white rice is an easy-to-digest carbohydrate option. Well cooked pasta and peeled boiled potatoes also work. Brown rice and whole grains contain more fiber and digest more slowly, making them better choices earlier in the day rather than right before training.
Sports options: sports drinks, carb gels, and carbohydrate powders like ALLMAX Carbion+ mixed with water.
Foods likely to slow digestion or cause discomfort if eaten too close to training: high fat dairy products, creamy sauces, large servings of whole grains, raw vegetables, fried foods, fatty cuts of red meat, and high fiber energy bars. These foods contain more fiber, fat, or both, which slows digestion and can interfere with nutrient absorption during exercise.
Cooked vegetables are gentler on the gut than raw ones before competition. "Easy to digest" does not always mean "healthier overall." These strategies are mainly for the pre-workout window or sensitive digestive periods.
How Many Carbohydrates Should You Eat Before a Workout?
There is no one-size-fits-all number. Carbohydrate needs depend on body weight, training volume, intensity, and how full your glycogen stores are from the rest of the day. Adjust based on individual digestibility and tolerance.
For typical gym sessions and shorter cardio (under 60 minutes): many people do well with 0.5-1 g of carbs per kg of body weight in the 1-4 hours before exercise, assuming a normal diet throughout the day.
For longer or more intense sessions (60-90+ minutes): approx. 1-3 g/kg in the 1-4 hours before, spread across meals and snacks.
For formal carb loading before long races (over 90 minutes): athletes should consume 8-12 grams of carbohydrates per kilogram of body weight daily for 1-3 days, with reduced training. Some athletes push to 10-12 grams of carbs per kilogram of body weight during peak loading days.
What those ranges look like in practice: a 70 kg runner carb loading at 10 g/kg/day eats 700 grams of carbohydrates per day for 1-2 days. A 90 kg bodybuilder preparing for a high-volume session might eat foods providing 90-180 grams of carbs in the 1-2 hours before training.
Factors that shift needs: training frequency (one session vs. two per day), whether you follow a low carbohydrate diet or a higher-carb approach, and whether you're starting the session fasted. More carbs are not always better. Overdoing it can cause digestive issues, a heavy feeling, or unnecessary calorie surplus leading to weight gain. Protein, hydration, and essential nutrients should also be present; this section stays focused on carb amounts.
Carb Loading for Strength Training and Bodybuilding
Most strength and bodybuilding workouts do not require formal carb loading. A regular diet with adequate carbohydrates supports the glycogen your muscles need for typical sessions. That said, resistance training does use muscle glycogen, especially during high-volume work targeting fast-twitch fibers across multiple sets.
High-volume bodybuilding sessions (10+ sets per muscle group) draw more heavily on glycogen than a quick 30-minute circuit.
Sessions lasting 90+ minutes with short rest periods can deplete enough glycogen to reduce performance in later sets.
Back-to-back sessions in a single day, or multiple demanding days in a row, benefit from higher carbohydrate intake to keep glycogen topped off.
Peak week for physique sports sometimes involves eating a high amount of complex carbohydrates to fill out muscle glycogen while managing digestion and reducing bloating. These strategies are highly individual and should be tested during training rather than assumed to improve appearance.
Carbs do not directly build muscle. Mechanical tension, progressive overload, and adequate protein are the primary drivers. Carbs help sustain the training that builds muscle by maintaining volume, intensity, and focus.
Lifters may use whole foods like rice, oats, and fruit, or convenience options like ALLMAX Carbion+ around workouts when a full meal is impractical.
"Carb loading for every leg day" is unnecessary. For most lifters, regular carb intake plus a well-timed pre-workout meal is sufficient.
Carb Loading for Endurance Training and Long Events
Formal carb loading was designed for endurance sports and is best studied in events lasting 90 minutes or more at moderate to high intensity. Research suggests carb loading can boost performance by 2-3%, and endurance can improve by 15-25% in events where glycogen depletion is the limiting factor [2].
Events where carb loading can be beneficial:
Half-marathon and marathon races.
Long cycling events (over 90 minutes), sportives, or century rides.
Triathlons, especially Olympic distance and longer.
Long team-sport matches. In a study of elite soccer players, increasing carbohydrate intake to ~7.5 g/kg/day by match day improved running distance, maximum speed, and sprint count compared to controls eating 5-6 g/kg/day [3].
A modern carb loading approach:
Normal or slightly higher carbs early in the week.
For many endurance athletes, carbohydrate loading can begin approximately 36–48 hours before competition, with around 10–12 g/kg/day while training volume is reduced.
Consume 10-12 grams of carbs per kilogram of body weight during peak loading days, emphasizing familiar, easy to digest carbs: pasta, bread, white rice, cereals, and peeled or cooked vegetables. Fast-digesting carbs are ideal 12-24 hours before a race, and lower-fiber options may be useful if gastrointestinal comfort is a concern.
Taper training volume to allow glycogen stores to build. Carb loading involves tapering training volume while increasing carbohydrate intake for 1 to 3 days before an event.
Potential downsides: carb loading can lead to temporary weight fluctuations due to water retention, since glycogen binds ~3-4 g of water per gram stored. Gastrointestinal issues arise if fiber or fat intake stays high, or if the athlete chooses unfamiliar foods. Proper hydration is essential during the carb loading phase to store glycogen effectively.
Many endurance athletes and female athletes alike should test carb loading strategies in training, not just on race week, to see how the digestive system responds. A recreational 5K, short ride, or 45-minute spin class does not require a formal carb load.
Pre-Workout, Intra-Workout, and Post-Workout Carbohydrates
Timing is about matching carbohydrate availability to training demands: start fueled, maintain fuel during long efforts, and replenish glycogen afterward.
Timing |
Primary Purpose |
Who May Benefit |
Before training |
Start exercise with adequate fuel |
Most athletes depending on meal timing |
During training |
Maintain carbohydrate availability during prolonged sessions |
Endurance and long/high-volume sessions |
After training |
Support glycogen restoration and recovery |
Especially relevant when training again within 24 hours |
Pre-workout carbs are the priority for most lifters and fitness enthusiasts. A well-timed pre-workout meal or snack covers the majority of fueling needs.
Intra-workout carbs (drinks, gels, powders) are most relevant for sessions over 60-90 minutes. The ISSN's Nutrient Timing position stand recommends approximately 30–60 g carbohydrate/hour during prolonged/high-intensity exercise, particularly when exercise extends beyond ~60–70 minutes [3].
Post-workout carbs support glycogen replenishment and recovery, especially when training again within 24 hours. Higher carbohydrate intake soon after exercise (e.g. within 30 minutes) can help accelerate glycogen replenishment.
Practical intra-workout options: sports drinks, diluted fruit juice, or carbohydrate powders like ALLMAX Carbion+ that are easy to sip and typically gentler on the gut than solid food during movement.
Not everyone needs intra-workout supplements. Whole meals before and after training are often enough for single daily sessions under 60-75 minutes.
ALLMAX Carbion+: A Convenient Carb and Electrolyte Option
ALLMAX Carbion+ is an easy-to-mix carbohydrate and electrolyte powder designed for pre-, intra-, or post-workout use. It fits into the fueling strategies described above but is not something everyone must use.
25 g total carbohydrates per serving with zero sugar, using a phased-delivery blend.
The carb blend includes Cyclo-D highly branched cyclic dextrin (~12 g), PER4ORM phased-release maltodextrin (~12 g), and AWM2300 waxy maize (~1 g), designed to modulate absorption and provide a gradual carbohydrate supply.
CocoH2 concentrated coconut water plus electrolytes (sodium 190 mg, potassium 100 mg, magnesium 60 mg, calcium 30 mg) support hydration and staying hydrated during training.
Mixes with water, roughly 100 calories per serving, available in Blue Ice, Lemon Lime, Pineapple Mango, and Unflavored.
Situations where Carbion+ may be helpful:
Early-morning workouts when eating a full meal feels heavy.
Long endurance sessions or high-volume lifting days when sipping carbs and electrolytes is easier than eating.
Athletes who find liquids easier to digest and tolerate during hard efforts.
Travel or competition days where portable, measured carbs are useful.
Learn more about ALLMAX Carbion+ on the product page. Carbion+ is optional. Athletes can carb load or fuel workouts using whole-food carbohydrate sources if they prefer.
Can You Get Enough Carbohydrates From Food Alone?
Most people can meet their carbohydrate needs, including for formal carb loading, by choosing whole foods and refined staples thoughtfully.
Grains and starches: rice, pasta, oats, potatoes, bagels, tortillas, low-fiber cereals.
Fruits: bananas, oranges, applesauce, dried fruit (in moderate amounts; dried fruit contains more fiber per serving). Soluble fiber in fruit is generally well tolerated, but eating too much at once before training can cause issues.
Other options: juices, sports drinks, honey or jam on toast, simple snack foods like pretzels or rice cakes. Muscle building foods that also supply carbs include sweet potatoes, oats, and rice paired with lean protein.
Supplements like Carbion+ become about convenience, not necessity: when appetite is low, when you need precise carb dosing during long races, or when your digestive system handles liquids better than solids. There's no requirement to use a carb powder. The choice depends on your schedule, taste, budget, and how your body handles different foods. Focus first on daily carbohydrate intake that matches training, then layer in convenience products if they solve a specific problem. Digestive enzymes in supplements or foods can sometimes help individuals who struggle to digest foods containing certain starches, but that is a personal consideration.
Common Carb Loading and Pre-Workout Carb Mistakes
Many carb loading failures come from misunderstanding how much to eat, which foods to pick, and how the gut reacts under stress.
Confusing carb loading with a single huge meal: carbohydrate loading happens over 24-48 hours of sustained high-carb eating, not one pasta dinner. Carb loading should occur over two days before an event for optimal glycogen saturation.
Eating far more carbs than needed: excess can cause GI distress, sleep disruption, and unnecessary weight gain. Match carbohydrate intake to your endurance event duration and body weight. Avoid excessive portions before sleep during carb loading.
Choosing high-fat or high-fiber foods close to the event: creamy sauces, large salads with raw vegetables, fatty cuts of meat, or fried foods are harder to digest. Excessive fat intake during carb loading can lead to gastrointestinal distress. Carb loading may cause digestive issues if high fiber is consumed. Stick to refined, lower-fiber carbs and cooked vegetables. Improper carb choices may result in bloating and discomfort.
Ignoring hydration and electrolytes: glycogen storage pulls water into muscles. Adequate fluid intake is important during carbohydrate loading, while electrolyte needs depend on sweat losses, exercise duration, environment, and individual factors.
Trying new foods or supplements on race day: improper carb choices can lead to digestive issues on race day. Test all carb sources in training first. Eat foods you know your digestive tract tolerates.
Assuming every workout needs carb loading or intra-workout carbs: for most sessions under 60 minutes, normal meals and a small snack are enough. Extra total calories from unnecessary carbs add up without exercise performance gains.
Focusing only on timing but neglecting total daily carbs: overall intake and consistent fueling habits matter more than tiny timing tweaks.
Frequently Asked Questions About Carb Loading
What is carb loading?
Carbohydrate loading is a short-term, high-carb nutrition strategy (typically 8-12 g/kg/day for 1-3 days) to increase muscle glycogen before long endurance events. It involves eating a higher proportion of carbohydrates while reducing training volume.
Is carb loading good before a workout?
Full carb loading is usually unnecessary before a regular gym workout. A balanced pre-workout meal or snack with carbohydrates is often enough. Formal carb loading is reserved for events where glycogen depletion limits performance, typically those over 90 minutes.
How many carbs should I eat before a workout?
Roughly 0.5-1 g/kg of body weight 1-4 hours before typical sessions. For longer or harder workouts, 1-3 g/kg in that window. For formal carb loading, athletes should consume 10-12 grams of carbs per kilogram of body weight over the days before an event.
What foods are digested quickly before a workout?
Bananas, applesauce, white toast, rice cakes, low-fiber cereal, sports drinks, and carbohydrate powders are easy to digest foods that work well close to training. Avoid high fat or high fiber options immediately before exercise.
Are carbs good before lifting weights?
Carbs can support exercise performance, training volume, and focus in strength sessions. They do not directly build muscle, but they sustain the effort that drives adaptation. Success also depends on overall diet, sleep, program design, and recovery strategies.
Should you eat carbs before or after a workout?
Both can be useful. Pre-workout carbs support performance; post-workout carbs help glycogen replenishment, especially when training again within 24 hours. For most people on a normal diet, the exact split matters less than total daily intake.
Is carb loading necessary for bodybuilding?
Most bodybuilders do not need full carb loading for daily training. Specific high-carb phases may be used strategically in contest prep or peak weeks to fill out glycogen stores while managing water retention and digestion.
Is Carbion+ good before or during a workout?
Carbion+ can be a convenient source of pre-, intra-, or post-workout carbs and electrolytes for those who prefer liquids or train for longer durations. It is optional and should be tested in training first to assess individual tolerance.
The Bottom Line on Carb Loading and Workout Carbs
Carbohydrates are a valuable fuel for many types of training, but formal carb loading is a specific strategy reserved for long endurance events, not everyday workouts. Carb loading can improve endurance by 15-25% in events where glycogen becomes the limiting factor, but that does not mean every session needs a multi-day protocol [4].
Match your carbohydrate intake to your training demands and goals.
Use easy to digest carbs and foods that are digested quickly when eating close to exercise.
Focus on total daily carbs and digestive system comfort, not just one pre-workout snack. Eat smaller meals closer to training and larger meals when time allows.
Reserve full carb loading for races or long events where performance depends on glycogen stores.
You can rely on whole-food carbohydrate sources, or, if you prefer liquids and convenience, consider options like ALLMAX Carbion+ as part of your fueling plan. Experiment in training, listen to your body, and build a carb strategy that fits your sport and your schedule. Nutrients from your overall diet always come first; supplements fill gaps when they genuinely help.
References:
Vitale K, Getzin A. Nutrition and Supplement Update for the Endurance Athlete: Review and Recommendations. Nutrients. 2019 Jun 7;11(6):1289. https://pmc.ncbi.nlm.nih.gov/articles/PMC6628334/
Hawley, J.A., Schabort, E.J., Noakes, T.D. et al. Carbohydrate-Loading and Exercise Performance. Sports Med. 24, 73–81 (1997). https://link.springer.com/article/10.2165/00007256-199724020-00001
Kerksick, C. M., et al. (2017). International society of sports nutrition position stand: nutrient timing. Journal of the International Society of Sports Nutrition, 14(1). https://doi.org/10.1186/s12970-017-0189-4
Hawley, J.A., Schabort, E.J., Noakes, T.D. et al. Carbohydrate-Loading and Exercise Performance. Sports Med. 24, 73–81 (1997). https://doi.org/10.2165/00007256-199724020-00001
