What is carb cycling?
Carb cycling is a diet protocol when you vary your carbohydrate intake from day to day. Most people follow a three day cycle where carbs for the day are either Low, Medium or High. Carb cycling can be used both when cutting and bulking, but is more commonly used for cutting.
Why carb cycle?
The main purpose of carb cycling is to manipulate Insulin release so that it only occurs at times/on days when its release is beneficial/necessary. This is on days/at times when activity levels and therefore energy requirements are high. At all other times, by limiting Insulin release, you will hopefully encourage your body to use fat for fuel whilst maintaining muscle mass if cutting, and limit fat gain whilst increasing muscle mass when bulking.
What is Insulin?
In brief, Insulin is the hormone released when blood sugars rise. It causes the uptake of glucose into the cells. Carbohydrates, especially sugars, cause a sudden increase of Insulin soon after eating which can be bad when fat loss is your aim. By controlling the release of Insulin via your carb intake, you can help your body burn fat for fuel whilst still providing it with enough energy during and after your workouts to further help with fat loss and muscle retention.
Why not just remove carbs from your diet all the time?
This may seem like a good idea as this will ensure Insulin release is minimal, but Insulin isn’t the enemy; it is beneficial at certain times due to its anabolic and muscle sparring effects.
Also, without carbs in your diet, you will experience a drop in energy/performance, mood swings, lack of focus, increased hunger, increased cravings and decreased metabolic rate which will make fat loss harder in the long term. Also, gaining muscle whilst not consuming any carbs is virtually impossible; people who eliminate carbs completely from their diet will only do so whilst cutting, whereas carb cycling diets can be used for both cutting and bulking phases to help with fat loss, or to limit fat gain. Eliminating carbs indefinitely from your diet is unsustainable and unhealthy; carb cycling is a lot more practical and can be followed all year round.
So are there any negatives to carb cycling? Yes, it requires a lot more planning than other diets and because there are in effect three different diets to follow (low, medium and high days) you need to be well organised and plan ahead/prepare your food accordingly. It is also a diet which will need to be adapted to each individual depending on several factors including activity levels, Insulin sensitivity and current body fat levels.
Think you’re up for giving it a go? Firstly you need to decide how you are going to split your week up into Low, Medium and High carb days...
Pick the day with the most demanding workout (usually leg day!) or the day you do high intensity cardio; this will be your High carb day. This means no more than 2 High carb days a week for most people, but I would say that the majority of people only need one High carb day a week. Generally speaking, the leaner you are and the higher your metabolic rate, the more necessary a High carb day is in order to help preserve muscle; the more fat you are carrying the less often you need a High carb day.
Low carb days will be on rest days so 2 or 3 a week, and the remaining days will be Medium carb days. In summary, High carb days should be on a heavy training day(s), Low carbs on rest days, and Medium carbs make up the remaining days.
The reason for matching your carb amount to your training is simply because you require the carbs for energy during your workout and post workout for recovery, whereas on rest days, energy requirements are lower. A typical week may look like this...
Monday – Medium
Tuesday – High
Wednesday – Low
Thursday – Medium
Friday – Medium
Saturday – Low
Sunday - Medium
In the above example, Wednesday and Saturday are rest days (Low), and Tuesday is Leg day (High). This is just one example; you will need to decide for yourself how you want to split your days depending on your training routine. You may need one more Low carb day or one more High day. You will probably already have a good idea of how well your body copes with carbs, and how easy/hard you find it to lose fat. If you find it hard to lose fat, I recommend an additional Low day in replace of a Medium day.
Now you need to work out how many calories your diet is going to contain.
To do this you first need to know how many calories your body requires on a daily basis to maintain weight. This can be roughly worked out by using the Harris-Benedict formula. Once you have this figure, you can then use it to know how many calories you need in order to lose weight. To lose fat you need to be in a calorie deficit so I recommend you start with a 15% calorie deficit (You can increase this as the weeks pass in order to achieve a steady loss of weight)
If I was to use myself as an example (I weight 133lb), my calorie amounts would look something like this...
My BMR is 2194 calories a day to maintain my current weight. To lose fat I want to be in a calorie deficit so 2194 – 15% = 1864 calories. This is how many calories I will need on Low and Medium carb days to ensure fat loss. On High carb days I will increase calories to my maintenance amount of 2194 calories.
Next you need to work out how many carbs to eat for each of the three days. As a starting point, use the below ratios to work out your macro’s...
40% calories from Protein
50% calories from Carbs
10% calories from Fat
45% calories from Protein
30% calories from Carbs
25% calories from Fat
50% calories from Protein
10% calories from Carbs
40% calories from Fat
Remember, Protein and Carbs both contain four calories per gram, and Fat has nine calories per gram.
My daily macros now look like this....
High day (2194 cal)
40% Protein x 2194 = 877 calories/4 = 219 grams
50% Carbs x 2194 = 1097 calories/4 = 274 grams
10% Fat x 2194 = 219 calories/9 = 24 grams
Medium day (1864 cal)
45% Protein x 1864 = 838 calories/4 = 209 grams
30% Carbs x 1864 = 559 calories/4 = 139 grams
25% Fat x 1864 = 466 calories/9 = 51 grams
Low day (1864 cal)
50% Protein x 1864 = 932 calories/4 = 233 grams
10% Carbs x 1864 = 186 calories/4 = 46 grams
40% Fat x 1864 = 745 calories/9 = 82 grams
Notice how Protein intake remains high regardless of whether or not it is a High or Low carb day. This is vital for muscle preservation/growth. Fat levels increase/decrease accordingly depending on carb intake. It is important that you do increase Fat on Low carb days otherwise calorie intake for the day will be low and along with an absence of carbs, your body will look to protein, either from muscle or food, via Glucogenisys, for energy which is not what you want to happen.
You need to make sure you log and constantly check your food intake. Never rely on guess work; you need to take the time to sit down and plan your diet in detail. You should aim to lose between 0.5lb and 2lb a week (depending on your weight). Anymore and you are more than likely losing muscle.
Unfortunately, with this diet there definitely isn’t a ‘one fits all’ as amounts will vary from person to person but the above is a good place to start; it may take several weeks of tweaking before you get the amounts right for you so don’t get disheartened if you don’t lose weight straight away. The main reason people fail with this kind of diet is because they go too high on High carb days and not low enough on Low carb days. You may find that you only need a High carb day every 2 weeks instead of every week, especially in the beginning; it totally depends on how well your body copes with carbs. Listen to your body and adjust accordingly. Carb intake should be adjusted before overall calorie intake is lowered. The further you are into the diet, the lower your carbs need to be on Low and Medium days.
Whatever you do, don’t cut calories too quick, give the diet time to work, and increase/decrease carb intake as you find appropriate. By starting with a relatively small calorie deficit (15%), you allow yourself more room for adjustments further down the line when fat loss slows.
If you start with a 15% calorie deficit, after a few weeks, if necessary, you can begin cutting calories further, but make sure you do this slowly. A further 5% reduction from your starting BMR should be sufficient. That means you start with a 15% deficit, then move onto a 20% deficit, then 25% and so on. However, as overall calories drop as the weeks/months pass, I suggest you keep you High carb day calories the SAME as they were when you first started. This means you will be in time eating over maintenance calories on High carb days but this will be beneficial because on the other days of the week, your calorie deficit will be greater and so the increase in calories will not only help refill glycogen stores, but increase Leptin levels and bump up your metabolism.
Your weight may fluctuate during the week due to increased/decreased water retention caused by varying carb intake. To ensure a true weight when you do your weekly weight in, make sure it is done first thing in the morning, on the same day every week. This way you weight will be comparable from week to week.
Now you know how and why you’re going to vary your carb intake for the week, but you can go one step further and increase the effectiveness of this diet even more by looking at the TIMING of the carbs on High and Medium carb days. This bit is a lot more straight forward and won’t vary much from person to person.
You’re consuming carbs on training days for the purpose of providing energy for your workout and energy to aid recovery/growth afterwards. This energy is also less likely to be stored as fat than at any other time so pre and post workout is the time to focus the majority of your carbs. On Medium carb days you may not feel the need for carbs pre workout so you may just keep them to post workout only, but this may depend on how far into the diet you are and therefore how low your carb levels are. On High carb days you can be less strict with your carb timing. Pre and post workout carbs will be essential, but you should also have room to fit some in at either breakfast or the meal after your post workout shake.
And there you have it! At first it may seem like a lot of info to take in, but once you get your head around it, it is actually a very simple concept to follow and the results speak for themselves. It works!