Carb Cycling

Most competitive athletes have used a low-carb diet at least once in their careers in an attempt to shed some body fat.  In the process, many of these athletes become carb-phobic, and end up steering clear of carbohydrates for years in an attempt to keep a very lean physique.  However, the truth is that many of these athletes are not seeing the incredible performance and aesthetic advantages of a nutrition plan that includes carbohydrates.  This doesn’t mean all carbs all the time.  It does mean strategically using varying carbohydrate intakes in conjunction with your training program with a methodology called “carb cycling.”

A carb cycling approach allows an athlete to gain and maintain muscle mass while getting into contest shape.  The strategy is relatively straight forward and is one of the most effective and sustainable ways to diet for most people.

The Science Behind Carb Cycling

Food quality and quantity are of paramount importance when trying to either gain muscle or lose fat. To lose body fat you need to be in a calorie deficit, and to accumulate body tissue you need to be in a calorie surplus. Almost anyone even moderately experienced in training and nutrition pays attention to these fundamentals.  However, the effect of nutrients on hormones and the subsequent effect of hormones on muscle gain and loss is not always considered – and it should be.

Hormones Involved

One of the primary players here is insulin.  The body uses insulin to transport amino acids and glucose into muscle cells.  Insulin is therefore largely responsible for moving the building blocks of muscle tissue into place.  It also limits the mobilization of nutrients stored in muscle, which means that under normal physiological conditions, insulin favors muscle gain and diminishes muscle wasting.  So insulin is a good thing, and the best way we can stimulate insulin release is to eat carbohydrate and amino acids.

What happens when we remove carbohydrates from our diets?  We release glucagon, insulin’s antagonistic hormone.  Glucagon encourages mobilization and utilization of stored glycogen and amino acids.  So, when your diet is lower in carbohydrates, glucagon is released and promotes the breakdown of healthy tissues rather than the building or maintenance of healthy tissues.

How This Gets Tricky – The Good and the Bad of Carbohydrates

Carbohydrates are generally good for us physiologically, but…

Carbohydrates – The good

Carbohydrate ingestion helps with the release of insulin.  Insulin makes developing a strong and muscular body dramatically more efficient, in part because training sessions are almost always more effective on a diet that includes carbohydrate.  And, while it is true that some amino acids can be converted to glucose through gluconeogenesis and that ketone bodies can be used as a primary fuel source following a proper adaptation period, your training sessions will still be stunted on a low or no-carb diet.   Moreover, you risk losing hard earned muscle mass because your body will turn to muscle tissue for amino acids that it can then convert into glucose.

Carbohydrate intake helps support a healthy metabolism.  Carbohydrate is involved in the the conversion of T4 (thyroxine) to T3 (triiodothyronine).  T3 is the active thyroid hormone, and a drop in T3 leads to a decrease in metabolic rate, which makes fat loss more difficult.

Carbohydrates – The Bad

Ok, we all want a strong and muscular physique, which is easier to achieve with a diet that contains carbohydrate.  However, too much carbohydrate (insulin) too often can lead to an unwanted accumulation of body fat.

So, eating carbohydrates is a good thing for us physiologically, but we need to be careful about eating too many.

Managing Carbohydrate Intake with Carb Cycling

Carb cycling is one of the best approaches to managing healthy levels of body fat and putting on or keeping muscle tissue.  This method has historically encouraged carbohydrate intake at those times human bodies are typically most insulin sensitive – in the morning and after workouts.  However, there is one more wrinkle.  The amount of carbohydrates and calories ingested varies each day with a carb cycling approach.  The benefits of this model are numerous.  It will allow you the benefits of burning fat and maximizing muscle accumulation, it will help limit the metabolic slowdown through relatively frequent calorie spikes, and it will favor long-term diet compliance.

This diet is really about eating the carbs and calories needed to prepare for, or recover from, your workouts.  That’s it.

Calorie Needs and Structuring a Carb Cycling Nutrition Plan

Before we can begin any structured nutrition plan designed to help you improve body composition we need to know your total daily energy expenditure – the calories you need each day.  Once we know you baseline calorie needs, then we can structure your program to achieve your goal.  There are many calculators in the internet world designed to help you figure this out, and these calculators are good starting points. However, there are a lot of factors that must be considered including but not limited to:  body weight, body fat percentage, sex, age, dieting history, training history, underlying physiological conditions (think Thyroid), daily activity in your job, and genetics.  If you would like help really dialing in on what your calorie needs are you really should hire an experience coach for at least 6 months to help you take the mystery out of “dieting.”

Once we have identified your calorie needs we then adjust your macronutrient intake (calorie intake indirectly) to meet your goals.  To gain muscle you must consume more calories than you use in a day.  To lose body fat you must consume fewer calories than you use in a day.   There is no magic surplus or deficit that people operate under when they are attempting a shift in body composition. However, a 10-20% deficit or surplus is a good starting place for most people.  And then we get to the interesting part – cycling your carbs!

Protein Intake – Protein intake will remain the same each day, regardless of the carbohydrate intake on any given day.  At least one gram per pound of bodyweight (even up to 1.5 grams per pound) is a good rule of thumb for most people.  However, moving to .8 gram per pound of bodyweight is a better number if you are above 25% body fat because it will help you moderate your overall calorie intake.

Carbohydrate Intake – Carbohydrate intake will vary between the high, moderate, and low days.   Moderate days should be built around a carbohydrate intake that matches your protein intake.  High days should be built around a carbohydrate intake that is 1.25 to 1.5 grams per pound of body weight.  Low days should be built around a carbohydrate intake as low as .5g per pound of body weight.

Fat Intake – The remainder of your calories for the day should come from healthy fat sources.  So you would total the number of calories consumed from carbohydrates and protein and subtract that total from your daily calorie needs. You then take that number and divide by 9 cal/g to give you the grams of fat you should be consuming.


Want to know more?????

There are a whole lot of tools out there that we can use to achieve healthy and sustainable body fat loss and improved body composition.  Carbohydrate cycling is just one valuable tool that really seems to work for people who do it the right way and are ready to commit to keeping track of their daily food intake.  To find out more about this dieting method and more please contact us at

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