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Carb Cycling For Fat Loss

The other day a client of mine asked me about carb cycling. Essentially, they wanted to know if they were missing out because we weren’t using it. Over the course of their training session we had a good chat about carb cycling.

We discussed why I didn’t think they needed to be using it. I expressed my opinion that in most cases it just makes life unnecessarily complicated and that keeping a relatively even calorie and carb intake day to day was more practical for most people. Why I didn’t think it was beneficial to them (they are currently in a muscle gain phase & eating a caloric surplus) but, why I use it sometimes myself and with clients in specific situations.

That specific situation is deep into a fat loss phase.

As with many conversations I have with clients I think about a bunch of stuff later which was relevant and would have helped make my point. This time I thought I’d put those thoughts down on paper in the hope it would help others (you the reader) decide if carb cycling would help them and, if so, how to implement it.


With that little bit of background out of the way here we go with my thoughts on the subject…


What Is Carb Cycling:


Carb cycling is the planned fluctuation in carbohydrates on a day to day basis. Traditionally, you would rotate through high-, medium, and low-carb days. During this time protein intake normally stays even while fat is increased as carbs are reduced.

Protein Will Stay Pretty Constant If You Decide To Carb Cycle
Why I don’t use Carb Cycling in a Mass Gain Phase:


When aiming to gain mass I do not often suggest people cycle their carbs much, if at all. On training days, their carbohydrate needs are high because of the high-volume training they are doing. On days, off from the gym their carbohydrate needs are high to recover and adapt to the training done and to fuel themselves for the next training session. Sure, carbs can fluctuate somewhat through the week and from training to non-training days, but I do not believe it is important to make these changes of a significant magnitude. After all you don’t grow in the gym. You grow when you are out of it and the body can put the nutrients to use to build bigger muscles. As a result, it doesn’t make sense to drop calories &/or carbs significantly on recovery days.


Carb Cycling for Fat Loss:


When fat loss is the goal this changes. In a fat loss phase the goal is to lose fat. D’uh!

The Great Philosopher Homer Knows – pic courtesy of windowsphone.com


To do this you will need to be in a calorie deficit.


As such, carbs should be viewed somewhat differently. They are less about fuelling the anabolic processes of building muscle and more about fuelling hard training which supports muscle retention.


During a cut retaining as much muscle as possible is of important. Whilst carbs are protein sparing, they are not as good at retaining muscle as having adequate protein intakes. So, during a diet you will need to take in sufficient protein to retain muscle and train in a way that promotes muscle gain. Training will be very like a mass gain phase. This protein intake will be very similar, or slightly, more than when gaining. To create a calorie deficit, you will need to reduce carbs &/or fats. This is where I think carb cycling can become a very useful strategy.


In the early stages of a diet you shouldn’t need to carb cycle. Creating a calorie deficit should be simple enough and will deliver results. The longer you diet and the leaner you get the harder it is to keep losing fat. After a period of time you will need to use more advanced strategies than simply eating less and moving more. Carb cycling is one such strategy.


Carbs Are Great Because…


The carbohydrates you eat are converted to glucose and either stored in the liver or sent out in the bloodstream. When muscle take up blood glucose they can use it for activity or repair. Most of this glucose is, however, taken in and stored by the muscle as glycogen.

Gratuitous Junk Food Pic…Nom nom! Yes They Are Carbs But Not The Ones You’ll Be Eating When Trying To Get Shredded

Carbohydrates are the dominant source of energy for CNS and athletic activities. They help to fuel gruelling training and aid recovery by replenishing muscle glycogen. Stored muscle glycogen is the primary and preferred fuel source for intense exercise. Approximately 80% of your weight training is fuelled by glycogen stores, a low glycogen state will compromise your ability to train hard. Carbohydrates are a huge advantage to hard-training individuals. Your carbohydrate needs are, therefore, based on your activity levels.


Carbohydrates replenish muscle glycogen levels after exercise and they also cause an insulin spike. Insulin is both anabolic and anti-catabolic. As such, it helps to build muscle and inhibit muscle breakdown. The second part of that last sentence is particularly important during dieting phases.


During dieting phases dropping carbohydrate levels has become popular. This is not entirely without merit as a reduction in carbohydrates can help to create a calorie deficit. When carbohydrates get very low, however, it can be detrimental to both your performance and physique. You need to eat enough carbohydrate to allow you to push through overloading training sessions. If you are low on glycogen then you risk muting the anabolic response to weight training.



As a result, you should keep them as high as possible for as long as possible. When the time comes that they do have to come down to low levels to create a calorie deficit you should preferentially time the carbs that remain in your diet around your training. One way to achieve this is to cycle them based on your activity on a given day. For example, on training days they will be kept high while rest days become an opportunity to drop them lower.

Blue Steel Tom. Work it baby! Yeah that’s it…oh screw it just purse your lips and look confused you idiot!

By consuming adequate protein, training with weights, and not chronically lowering carbs you mitigate against the risk of muscle loss. Having lower carbs on rest days won’t suddenly turn you into a catabolic, muscle wasting machine. You will hold muscle just fine. In fact, the body is very adept at retaining muscle once it has been built and hung around a while (that’s a good reason to use maintenance phases after bulks. Watch my video on this topic here). So, now the muscle loss fear is out of the way let me move on to highlighting how carb cycling can help you get leaner and stay bigger.


By cycling your carbs, you can maintain the same overall weekly deficit as you would by keeping them even across the week, but you will have better quality training because of their proximity to the training session. For example, say have 2,400kcal per day to lose fat at your desired rate. This is 16,800kcals a week (7 x 2,400). For the sake of argument let’s say you weigh 80kg and are eating the following macros to hit those 2,400kcals:


Protein 175g

Fats 80g

Carbs 245g


(If this accurately describes you…good job! You have done solid work setting up your nutrition so far).


Then progress stalls! You need to adjust calories downwards and based on experience need to drop by 300kcals (2,100kcal per day or 14,700kcal per week) to kick start your fat loss again. You decide to just drop calories from carbs so your new plan looks like this.


Protein 175g

Fats 80g

Carbs 170g


Let’s say you are doing 4 weight training sessions a week. I suggest something like:


Mon – Upper Body

Tues – Lower Body

Wed – OFF

Thurs – Upper Body

Fri – Lower Body

Sat & Sun – OFF


All of a sudden, those 4 training sessions suck. You have no energy to get through them. Don’t get a pump and just feel flat, small and weak. Not fun!

Feel Like This Before Training?

If your training goes down the drain and you start getting weaker then the risk of losing muscle increases. Suddenly, you are using lower weights, getting fewer reps and doing less overall volume. Combine this with being very lean and muscle loss becomes a genuine concern.


How to avoid that?


Use carbs for what they are best at. Use carbs to your advantage. As previously mentioned, carbs fuel high intensity activity (e.g., weight training). By cycling carbs, you can time them to be consumed before and after training. This allows you to get the benefits of them as a fuel and their ability to replenish glycogen after training. All while you can stay in an overall calorie deficit. By switching your intake to meet your demands you can get high quality training in. This has all the physiological benefits listed above and a huge psychological benefit. It is much easier to stick to a gruelling diet and training plan if gym performance is good, you get a skin splitting pump and you can see results in the mirror.


Sticking with our 4 day a week Upper/Lower example a simple carb cycle plan of:


Mon – train & high carb

Tues – as above

Wed – off & low carb

Thus – train & high carb

Fri – as above

Sat & Sun – off & low carb


Would work better than simply keeping calories even across the week. Manipulating things this way will mean that training is good and recovery is sufficient after rest days.



In simple terms, it is as easy as switching to a high and low carb day by pushing more carbs to training days. The complexity comes from respecting the fundamental nutrition principle of energy balance. You cannot just chuck carbs in on the training days and go low carb on non-training days. If you do this and end up in a surplus then fat loss will stop.


You know that a weekly total of 14,700kcals was adequate to have our 80kg example losing fat well. So, that total should not be exceeded. It just needs to be distributed sensibly. To achieve this, I would suggest increasing carbs on training days while reducing fat intake. Then on non-training days reducing carbs significantly and bumping fat back up to the baseline levels previously set.


For example,


Training day:



Protein 175g

Fat 60g

Carbs 230g


Non-Training days



Protein 175g

Fat 80g

Carbs 150g


This new set-up respects the overall weekly calorie total of 14,700kcals. It supplies sufficient protein to retain muscle mass. It also provides sufficient nutrition to fuel hard training. The higher levels of fat on non-training days help to maintain hormonal function while the fat intake on training days is not so low as to significantly impact hormone levels. Fat is also quite satiating and higher levels on non-training days should help to offset any increased hunger from the slightly lower calorie intake.


When this approach stops working and calories must go lower the difference in calories and carbs from training to non-training days might become more dramatic. For example, if calories need to be reduced by another 300kcal (1,800 per day & 12,600 per week) to get completely shredded then the days might change to:


Training day:



Protein 175g

Fat 50g

Carbs 191g


Non-Training days



Protein 175g

Fat 70g

Carbs 80g


Now, as you get leaner dieting gets harder so, I’m not going to try and pull the wool over your eyes and say that this final step is easy. I will, however, say that if you want to get peeled then a level of suffering will have to occur. What you should do is try to minimise the suffering and maximise the results. Cycling your carbs in this fashion helps you to do this better than just keeping calories at a standard 1,800 per day, 7 days a week. If you did that then every day would be pretty low carb. Training would suck and you would have no variety to your diet. Having the fluctuations in calories from carb cycling allows you maintain training intensity for as long as humanely possible. Increase muscle retention. It also allows you to eat some tasty carbs even while getting to exotically low levels of body fat and, on rest days allows for some higher fat foods. This means you can enjoy certain foods that you could not fit into an evenly distributed 7-day plan. For example, when dieting I really like eggs, avocados and peanut butter on low carbs days. Admittedly these aren’t eaten in large quantities (it is still dieting folks) but I do manage to eat a reasonable serving of them. Meanwhile, simple pleasures such as porridge, caramel snack a jacks with jam, potatoes and stir fry noodles provide my carbs and sanity on training days. If this was done on an even calorie split the days would mean I could probably eat a quarter of an avocado, two eggs and just sniff the peanut butter, while having a small bowl of porridge and 3 licks of a dry prune (thanks to Charles Poliquin for the timeless dry prune quote). I would rather be able to have a whole tablespoon of peanut butter 3 days a week than only being able to inhale the tasty fumes 7 days a week (mmmm getting high on peanut butter fumes)!


So, long story short, if you are someone who has been dieting a while, is lean, but wants to get leaner and has started to find that training quality is poor and your energy and motivation to train has dropped then try carb cycling. It might well be the tool which can get you from lean to “holy shit I can see that guys pancreas working” lean.


Go here to grab my 12 week Fat Loss Training & Diet Plan to get you in the best shape of your life.

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