Giant plate of spaghetti for carb loading performance

Carb Loading

Carb Loading! This may be a strategy you have heard of when it comes to fuelling for sports or activity, but is it necessary and effective. We explore carb loading and the possible pros and cons to utilising this eating method.  


Carb loading refers to a nutritional strategy whereby a person deliberately eats high volumes of carbohydrate in the lead up to a particular sporting event or activity. It’s a popular performance eating tactic often used endurance, long distance athletes such as marathon runners, cyclists. Or in prolonged power sports such as rugby, football, tennis etc.

Carbohydrates are your bodies preferred energy source. These are broken down by the body once digested, then stored in the liver and muscles in the form of glycogen, ready to be used for activity.  

There are several well known approaches to carb loading but typically these involve higher carb meals over several days in the lead up to an event. The basic idea is that by the time your event comes around, you’ll have. A plentiful supply of energy that should fuel your performance optimally. 

Generally our bodies can store around 2000 calories in the form of glycogen from carbohydrates. During exercise these supplies are used to fuel movement. An event such as long distance ruining will see these levels depleted after about 90 – 120 minutes. At this point you may start to experience fatigue. As a result your pace may slow, with muscle cramping and experiencing dizziness. In the endurance world this is often referred to as “bonking.” 

A “geeky” bit: ATP (adenosine triphosphate) is an energy carrying molecule found in our bodies. Energy comes from carbs, fats and sometimes proteins. When energy is needed it is converted from storage molecules (carb and fat stores first) into ATP. However ATP is converted much slower from fat than it is from carbs, which is why carbohydrates are preferably for energy demands we put on our bodies. In practical terms this may mean that not having enough stored carbohydrate could reduce your ability to perform your best during sports.


Water For Hydration

Carbohydrates also help keep you hydrated. For every gram of carbohydrate stored the body store 4g of water. 

400g of stored carbohydrate is about the amount we can store before we convert this into adipose tissue (body fat). 

This equates to 1.6kg of water being stored, which is preferably for sporting activity, especially on hotter days.

Carb Loading Stratagies

Essentially carb loading involves deliberately increasing the amount of carbs in the lead up to an event. However there are several ways to do this. The major difference between them all is TIME. Each approach is slightly different in the time it takes to consume and stock up on your carb sources. And all involve purposefully limiting exercise whilst you build your glycogen stores through a temporarily high carb diet.

Again all also involve a low fat diet during this period, replacing fat intake with carbs. Fat is stored differently and is less efficient during endurance activities at being broken down and used as fuel, so keep you fat intake low during carb loading phases. This ensures a optimised approach. Options range from around a week of carb loading, to a just a few hours before an event. Continue to find out more.

Carbohydrate Sources

Carbohydrate sources, Carbs for fuel

During carb loading aim a mixture of complex, starchy carbohydrates in the lead up to an event, such as; oats, sweet potatoes, whole meal rice, wholegrain bagels / bread, unripe bananas, natural popcorn etc, and simple carbs like white pasta, bread, white rice, bananas.

Complex sources take longer to digest and don’t spike insulin levels as much, which helps sustained energy release. However they can be harder top digest due to high fibre content, which can leave you feeling full and uncomfortable. Which isn’t ideal if you’re trying to eat more carbohydrate.

In contrast simple carbs break down much faster and are easier to digest which can help you get in more. They do though spike insulin which can give your a burst of energy but leave you feeling a little lethargic. If you’re not used to large amounts of carbs stick with simpler options, your gut won’t be used to a dramatic increase in fibre rich foods which may leave you feeling uncomfortable.

View more carbohydrate sources here. During the event itself its all about rapid carb sources like glucose drinks, maltodextrin, honey, raisins, fruit juice etc. Which sources you choose largely depends on your event duration and type. We will explore more on this soon.

24 hours before load

This is a simple last ditch attempt to stock up on you fuel before an event. Infamous mounds of pasta being consumed by people and shared on instagram for all to gasp at. Often just hours before the big day. 


Ensure to have a complete day off exercise the day before your event. During this day you’ll focus on a high car intake.

  • Consume 10g of carbs per 1kg of body weight. So for a 75kg person 750g of carbohydrate spread throughout the day (over a 24 hour period). You may break this down into 5 meals / snacks (150g per meal, for 5 meals, for example.)
  • Event Day – The morning of the event your breakfast should be high carb, low fat with some quality protein. Aim to. eat 1.5-2.5g of carbs per 1kg of bodyweight 3-4 hours before the event and between 25-50g of protein.
  • Ensure to keep your fluids high during any carb loading method, 3-6 litres a day. 


  • This approach is simple and requires less adherence and thought. Which makes it an easier option for people who have less time to devout to pre event prep. 


  • Eating this amount of carbs in 1 day is a lot for anyone. Often it can result in people feeling overly full and uncomfortable.
  • Fibre in carbs can cause bloating and constipation. With just hours before an event, this can be considerably debilitating. 
  • Furthermore it can have an adverse effect and leave people feeling lethargic the next morning (the day of the event) which isn’t how you want to start your day. 

Coaches Conclusion

Studies have demonstrated this to be an effective fuelling strategy. However it would not a preferable approach in my opinion, But can be a used if you’re a person able to tolerate larger portions and usually eat a higher carb diet. Or occasions you have entered an event last minute and need the fuel. Dramatically increasing carbs, without nutritional conditioning can cause extreme gut discomfort. I think there are better ways to approach carb loading should you have the flexibility of a little more time. 


This carb load variation is a popular choice with many. It starts 3 days before your event. The fourth being the event itself. Studies measuring the affects of this method used the 10g per 1kg ratio similar to the above. However I’d suggest a slightly lower amount to prevent excess fat storage. 


  • Day One – You need to train extremely hard on this day. Ideally for over 90 minutes at a moderate to high intensity. You are aiming to create an exhaustive state where you have used most of your bodies glycogen stores. Eat 8g of carbs per 1kg of body weight, spread evenly throughout the day. So a 75kg person would eat 600g of carbs of this day. Ideally from complex carb sources.
  • Day Two – No exercise on this day or next. You’re now in recovery mode and priming your body for your event. Eat 8g of carbs per 1kg of body weight, spread evenly throughout the day. So a 75kg person would eat 600g of carbs of this day. Ideally from complex carb sources. 
  • Day Three – Same as day 2. No exercise and a 8g per 1kg of bodyweight. 
  • Event Day – The morning of the event your breakfast should be high carb, low fat with some quality protein. Aim to. eat 1.5-2.5g of carbs per 1kg of bodyweight 3-4 hours before the event and between 25-50g of protein.


  • With a longer approach you are able to ensure glycogen stores are thoroughly digested, absorbed and maximised.
  • The additional days can better enable your body, particularly your gut and digestive system to adapt to new levels of carbohydrates. Preventing discomfort and addressing other potential side affects like constipation and lethargy. 
  • A hard session three days out may help your confidence should the session go well.


  • This approach is slightly more involved and requires more attention over a three day period, which for some can be problematic. 
  • It’s possible that some people “spill over.” This is jargon for the conversation of carbohydrate that is converted and stored as body fat. However given the high carb increase is only over three days it likely that your event will use these reserve anyhow.
  • In contrast; a hard session three days before an event could result in a few negative affects. (1) Increased risk of injury. (2) May decrease confidence and increase anxiety. 

Coaches Conclusion

A solid approach and one backed by research. The idea behind implementing an exhaustive training session first is to burn old glycogen stores up and replenish them with fresh ones. However studies have found that this isn’t necessarily any more beneficial, with benefits being negligible at best. An alternative version to the “3 day classic” is the “3 day modified,” which is a more up to date version following recent research and data. It’s exactly the same protocol, minus the initial hard training session. 


A very involved and calculated approach that requires a good understanding of nutrition. For most people this method would be best implicated under professional guidance from nutritional and fitness coaches.  


  • During the first three days you will continue with you fitness programme, but eat a low carb diet during this time frame. This allows your glycogen stores to be depleted at a slower rate. Low carb in this instance is 15% of your daily calories from carbs and the remaining amounts split between fat and protein in accordance to you personal macro split. For example if you eat a 2500 calorie diet per day, only 375 of these calories should be consumed from carbohydrate. 
  • On days 4 perform a very light exercise session. You’re carb in take on this day should be increased to 70% of your calories from carbs. Using the above as a consistent example if you’re eating 2500 calories per day, 1875 calories should now come from carbs. 25% from protein and 5% from fat. 
  • Days 5 & 6 see you eat the same ratio as day 4, but now you stop all exercise completely. Your priority is rest and replenishment. 


  • A longer carb loading approach can help your body adapt to increases in carbohydrates. 
  • This can result in less gut stress and discomfort.


  • The longer period requires more attention and focus from you. It’s more involved and for some people this may not be practical.
  • Studies show that depleting energy reserves before they are topped up isn’t necessarily needed like it was once thought.  You can use this protocol over 6 days without the exercise and still benefit from maximal glycogen stores during your event. 

Coaches Conclusion 

A robust approach to carb loading, but one I’d suggest clients use in conjunction with their coach or others who have experienced doing this before. This strategy allows people to increase carbs slowly and for that reason this protocol may favour people that experience gut irritations due to carb / fibre sensitivity.



So you’re carb loaded, glycogen stores are maxed out, you’ve eaten your high carb pre event meal and now you’re minutes from the event itself. 

Hydration and nutrition remain very important. At this stage you have enough enough fuel on board that should sustain your efforts for 90 minutes.

As your glycogen stores deplete through the event so will your performance. So how do we ensure you’re at the top of your game throughout?

To maximise fuel levels aim to consume plenty of water during the first 60 minutes of the event. Not excessive but you shouldn’t feel thirsty. You’re becoming dehydrated if you experience the sensation of thirst. Too much though and you’ll probably need the bathroom. Being mindful is often enough to get your hydration right at this stage. 

After 60-90 minutes start to take in rapid carb sources from liquid or gel based sources. These are extremely fast acting and will prevent fatigue. A good option would be something like a carb drink mixed with water. Something like HR Labs “Carb Up” available here

In addition to your carb drink, you’ll want a hydration source more adequate than water. An electrolyte drink is perfect. These will help to replenish micronutrients such as potassium, magnesium and calcium. Micros like these prevent muscles from cramping, help respiration and energy release. 

In hour carb drink pop in 1 / 2 electrolyte effervescent tablets that dissolve and can be consumed within the carb drink itself. A good option would be these: Phizz Hydration Tabs.

When considering how much carb source to put in your bottle and drink after 60-90 minutes use the following ratio. 0.75g of carbs per 1kg of body weight, per hour. Which means a 80kg person should consume around 60g of fast acting carbs every hour after 60-90 minutes of intense exercise. Eg marathon running, long distance cycling etc. 


With you long event done recovery nutrition is important for injury prevention, adaptations, and returning you to a “normal” state as quickly as possible. 

Within 30 minutes of finishing aim to consume between 50-100g of fast acting carbs, 25g of quickly digested protein and some electrolytes. This is a great blend to help muscles recover, replace energy and increase hydration levels.  A good example might be a white bread honey sandwich with a protein shake and zero calorie sports drink perhaps? For more information on recovery recipe ideas get in touch with your coach here.


You body its in a constant state of breakdown and repair and intense exercise will inevitably begin to break down muscles. To prevent muscle loss and increase your ability to recover you should consume small amounts of protein before, during and after your event. To keep this simple: BEFORE eat up to 30g (10-20g is fine) of protein with your high carb, low fat meal. DURING consume 10g of protein every 60 minutes. AFTER make sure you get in 25g quickly once finishing. A whey protein (available here)  source would be ideal followed by a slow releasing source a few hours after (chicken, tuna, turkey etc). This helps to put you in a protein positive state initiating muscle protein synthesis (MPS) which aids recovery, preventing muscles from breaking down and used for fuel. 

Don’t go crazy with the protein. Too much can slow gastric motility and emptying which can prevent vital nutrients from being absorbed during the event and leave you feeling “clogged up.” 

Carb Backloading

Carb Back Loading

This isn’t a new practice but one that has snowballed in popularity over the last few years. Fundamentally carb backloading involves a low carb carb diet upon waking until the evening part of the day from around 5pm onwards. Whereby you consume the majority of your daily carbohydrates during this time and before bed. This then often involves high protein and moderate fat meals for breakfast, lunch and snacks. Purest suggest that for this to work effectively carbs should be limited to less than 30g until the 5pm mark. 

To confirm your macro split would remain the same but your carbs are consumed at night, which is the only differing element. 

Pioneers of this eating strategy applaud it for its weight management benefits. Largely thought to have appetite suppressing benefits and complementing your natural insulin sensitivity fluctuations throughout a 24 hour period. In turn promoting fat loss, increasing energy and building muscle more effectively.

A study conducted by students at Cambridge University found that eating carbs predominantly at night may in fact help reduce appetite the following day. Combined with an adequate exercise regime finding also indicate favourable outcomes towards weight loss.

However before we all start having our porridge for our evening meal its worth mentioning that these studies are small and sparse, more research is needed before we begin to get really excited about the potential this eating pattern may have. 

The idea of the diet is that depending on the time of day our bodies digest and absorb carbs at different rates. Which depending on when we eat carb rich foods can either be favourable or not.

Theorists suggest our bodies process carbs differently, depending on our activity. When in a rested state insulin brings more carbs to fat cells, whereas when in an active state insulin carry carbs to muscles to be used as fuel. Over time carbs sent to fat cells can lead to weight gain.

It’s thought that insulin sensitivity aligns with our bodies sleep-wake cycle (circadian rhythm). And therefore at the end of a day or after considerable movement or exercise our bodies are more adapted to “accept” and process nutrients. Therefor carb backloading is a suggested eating strategy to optimise the fuel we are eating, ensuring we use this as fuel and not store it as fat. 


Before I give you my perspective, it’s important to know that my role as a coach isn’t about telling people what to do. I need to be able to highlight the pros and cons with regard to concepts and strategies and empower clients to make decisions that suit their individual needs. A good coach follows the science but is lead by clients. That said here’s my perspective on carb backloading, based on the current understandings. 

Firstly when it comes to weight gain or fat loss I don’t think this approach is superior to any other form of controlled or monitored way of eating. I think that this approach would be just as affective as an even spread of your macro split. Studies have shown time and time again that the biggest driver of considerable fat loss or gain is in relation to the amount of calories you eat. Since this approach is suggesting no change until the calories or macro split I’m hedging my bets that results long term would be the same. I think another limitation to this diet style would be adherence. Some people may struggle to successfully fit this into their lifestyle and daily living.

I do though see the logic to this approach, mainly from an appetite stand point. 

Heres who I feel this approach my help.

  • People who struggle to regulate appetite –  similarly to the keto diet (which this is like a mini version of) studies have shown limiting carbs to be favourable to appetite control. Helping people feel less hungry. Which in turn may prevent people from overeating and gaining weight. This for me is huge positive. 
  • People who make poor choices in the day dues a busy lifestyle or limited access to nutritious foods. EG lorry drivers, regional sales reps, office works etc. 
  • People who historically graze more at night. If you fall into he night time feaster category then this might be a protocol I would suggest.

Ultimately I’m neither in favour nor  against this approach. If you feel it would work for you and that you can adhere to this style of eating then it absolutely is going to help keep you lean, fit and healthier. Should you wish to discuss this with me or any of our coaches then please do get in touch here.

The run down

The Run Down Orange Outfit Lady Running Down Stairs

General Details 

  • Carb loading should only be used for endurance events last longer than 60 / 90 minutes. Using it for workouts, anaerobic activity such as weights and events less that 60 minutes isn’t usually necessary. It if weight management is a focal point fro you using carb loading regularly will likely result in weight gain in the form of stored body fat. 
  • Carb loading should be practiced to help the body become used to higher amounts of carbs. Practice with different strategies in the lead up to an event. Do so only for practice sessions lasting longer than 90 minutes though. For the same reason as mentioned above.
  • There are many strategies when it comes to carb loading. We have broken it down to what we feel is the most affective and widely used variations by serious and professional athletes. These include the: “24 Load,” the “3 Day Classic Load,” and the “6 Day Classic Load.” 
  • If your new to carb loading and for best results we advise doing so firstly by working closely with your coach who can help you understand and adapt the approach accordingly. 
  • Generally as a coach I’m in favour of either a 3 day or 6 day approach and feel both can be effective. It largely depends then on what a person prefers to use.
  • I think a 24 hour strategy can help but entails possible negative side affects such as lethargy, constipation, bloating and stomach ache. If you’re looking for increased performance this could be detrimental to results.

Key Fundamentals 

  • Carb loading isn’t just eating as many as you can. Broadly; aim to consume 10g of carbs per 1kg of body weight each day in the lead up to your event. Focus on simpler carbs lower in fibre to reduce fullness and bloating. Sources such as white pasta rice, bread, bagels, bananas and oranges. Complex carbs can be used for main meals to help ensure sustained energy release and reducing spikes in insulin levels. Closer to the event 2 days out is good, start reducing your fibre intake. This will prevent negative side affects like stomach aches etc.  
  • Make sure your fluid intake remains high throughout your carb loading phase, during the event itself and after. Increasing carbs puts higher demands on fluid intake. Remember for every 1g of carb absorbed so is 4g of water. This can be significant in helping you stay hydrated as well as effectively fuelled. 
  • Fat intake during carb loading should be kept very low. 5% – 10% of your calories per day should come from fat during this time ideally. Replaced by carbs to ensure adequate calorie intake. 
  • Protein should be consumed in moderate amounts to prevent muscle breakdown. Protein is glycogen sparing which greater ensures carbs are left to do their thing during your event. If however you’re on a high protein diet, flex this down some during a carb load phase. Adding protein to your diet slows gastric motility and digestion. Great from a day to day perspective, but not when we want the body to soak ups as much energy and goodness in the form of nutrients as it can. 
  • You will gain weight when carb loading – Its impossible not to. Think about its if you store 4g of water per 1g of carbs you’re going to hold on to much more water weight. It’s also impossible to know exactly at what point your muscles are full of glycogen and when you’re converting excess carbs into adipose tissue. weight gain is a positive sign in this instance, it means you have energy ready to use. You won’t gain masses of weight and most will be burned during your event or in the following days post event.