I have been a certified fitness trainer (CFT) for three years and have earned a Bachelor of Science (BS) in dietetics, graduating with Magna Cum Laude honors. Despite my extensive experience as an athlete and educational background I am constantly being told that, "you do not eat enough carbohydrates".
This is a common misconception that some people have created due to the fact that they do not know much about my nutritional practices as an athlete; therefore, the latter quote is a false accusation. The people jumping to conclusions should become willing to learn about different scientific approaches towards nutrition.
This leads to the introduction of the topic being covered in this review of literature, the Anabolic Nutrient Timing Factor (ANTF). I first learned about the ANTF through Paul Cribb B.S. Sci. HMS. Paul is a research scientist whom studies muscular dynamics he is also the research director for the supplement company AST Sports Sciences.
When I first learned about Paul's theories I became ecstatic; I thought to myself "finally another professional in the field that will back my theories and beliefs towards nutrition."
This paper will discuss timing the macronutrients in scientifically proven method in order to assist the athlete in gaining results from their training methods via nutrition. Perhaps of equal importance is the extensive personal experience that I have with this method of nutrition.
It may seem extreme to some but the people that are following this practice are not your typical Americans. The individuals practicing the ANTF are athletes striving to get an edge on their competition. Furthermore, they are going about it through the safe and intelligent way, which utilizes proper dietetic practices.
The results that they are experiencing are phenomenal. The athletes willing to get serious about their nutritional practices and use the ANTF will have full, hydrated, nutrient dense, and glycogen filled muscles.
Some Info About Carbs And Insulin
Having been so deeply criticized concerning my carbohydrate intake throughout my years as a collegiate athlete and natural bodybuilder I begin by deeply covering the misunderstood macronutrient. If an athlete consumes carbohydrates at the right times the macronutrient can benefit the athlete by functioning as it is supposed to.
Carbohydrates are supposed to replenish glycogen stores in the liver and muscle cells while supplying the body with a sufficient amount of blood glucose for immediate energy. Carbohydrates work in conjunction with insulin.
Insulin is one of the most powerful hormones present in the human body. When used and timed correctly great things can happen in the carbohydrate insulin relationship. Having stated that, it is important to understand that timing is everything when speaking of insulin.
If you allow your pancreas to secrete insulin at a time of insulin insensitivity you are setting up an internal environment, which supports disaster. Insulin insensitivity can be described as a time, which the muscles are not primed for glucose uptake and storage.
This is the typical every day scenario for sedentary individuals that consume too many carbohydrates. If this practice occurs over a prolonged period of time individual can become insulin resistant. When this occurs the target cells along the muscles and other tissues fail to respond to the presence of blood insulin. This condition is related to the pathology of obesity and diabetes1.
The science behind increasing muscle tissue lies in a complex interaction involving the muscles, liver, and blood. Additionally, the amount of amino acids that are present inside of these tissues is also significant factor.
To maximize muscle growth and athletic potential the natural athlete must utilize every opportunity that allows them to enhance their internal environment promoting anabolism. The successful intelligent athletes are forever concerned with their entire physiology.
For example, when an athlete consumes a meal it does not necessarily mean that what they wanted to happen through the nutrient consumption will actually happen. Consuming protein does not mean that the nutrients and amino acids from the food will be used for muscle growth.
ANTF: Keeping Your Body In An Anabolic State
The core of the ANTF is insulin and nutrient manipulation, which stimulates your pancreas to secrete the powerful hormone. If an athlete can master this technique they will be able to keep their body's metabolic pathway in an anabolic state. Whey Protein is a common form of marketed protein in supplemental form. Therefore I will use whey as an example several times throughout this paper.
Whey protein can be used in conjunction with insulin secretions to assure maintenance and rebuilding of muscle mass. Managing the amount of insulin present in the blood is the key to success, in the ANTF. The pancreas, which sits directly beneath your stomach, secretes insulin.
Insulin will be secreted into the bloodstream when the food you consume triggers the need for secretion of the hormone. Insulin however is not released in significant amounts every time that food in consumed. Insulin reacts specifically in response to carbohydrate foods, particularly the ones having a high glycemic index rating.
Insulin assists the body in glycogen replenishment via the active transport of nutrients into muscle cells by way of the sodium potassium pump, which is located in the cell surfaces of the muscles. In doing so, insulin assists in keeping the body in a state of anabolism and actually prevents catabolism2.
However, it is important to understand that the mere presence of insulin does not only promote muscle cell anabolism, it promotes cell anabolism in general. Therefore, if your muscles are not ready to take in the nutrients because they are saturated with glycogen or the physiological environment is not right, adipose cells will always welcome the addition of stored energy.
There are two aspects of concern when speaking of manipulating insulin secretion. The first aspect lies in knowing how to time the consumption of insulin associated high glycemic carbohydrate based foods. The second step involves adding protein to the carbohydrates during the advantageous physiological time frame.
Protein consumption provides the body with the right material for optimal muscle growth and recovery. When muscle cells are depleted from exhaustive resistance training they are in need of amino acids.
If your blood insulin level is high insulin will push the protein into the muscle cells. Insulin has the ability to drive protein and carbohydrates into muscle tissue, but the consumption of protein alone will not stimulate insulin secretion.
Following the guidelines of the ANTF will enhance the uptake of any type of protein that is utilized in post resistance training meals (2). Additionally it is important to know that some proteins are higher on the biological scale that others making it safe to say that all proteins are not created equal.
Whey protein will provide the bloodstream with a quick surge of amino acids, which is needed immediately following training. Research shows that in a state of low blood insulin, whey protein will be used as energy, which is not a wanted condition3.
The amino acid profile in whey protein has a high array of gluconeogenic amino acids, and they are easily used for energy purposes4.
This makes whey protein sound like a poor choice of protein but the amino acids are also critical in stimulating protein synthesis, which is necessary for muscle growth and repair to occur. The difference in getting your whey protein to be used as an energy source or used to generate protein synthesize is managing your blood insulin levels.
Using Protein With Carbs Post-Workout
To assure that your protein is used correctly and promoting anabolism use it when blood insulin levels are soaring high. When insulin is present in high doses the precursors that allow for gluconeogenesis to occur are drastically decreased5.
Consuming the prescribed type of carbohydrates at the appropriate time mixed with protein creates the optimal anabolic environment. Just as eating protein is not guaranteed that the amino acids will be used to repair muscle tissue; consuming carbohydrates is not a guaranteed reason to feel confident that they will replenish glycogen and proving energy either.
Athletes must consume their carbohydrates following their training in order to get the blood insulin levels up rather quickly while the metabolic pathway is supporting anabolism3.
Low blood sugar and low insulin levels cause the secretion of catabolic hormones, which is an unwanted condition for athletes. The post-training time frame calls for and if utilized properly will allow for the restoration of glycogen and blood glucose. It is at this crucial time that the process of reloading nutrients is priority in physiologic terms.
To take advantage of this precious moment the athlete should have a dose of simple carbohydrates. These carbohydrates should come in the form of a liquid for the ease of digestion. The athlete should consume about 0.5 grams of carbohydrates for every kilogram of their body weight immediately following their training session6.
The best type of carbohydrate at this time should come in the form of a liquid. When trying to get blood insulin levels elevated using a juice containing a high sucrose to fructose ratio is preferable. Grape, orange, or tangerine juices are a few examples of liquid carbohydrates that fit this description5.
Carboplex® is also an optimal glycogen reloading supplement which is comprised of the carbohydrate maltodextrin. Another great choice available on the market is Endurox R4®. This product lists glucose as the primary carbohydrates ingredient, which is also a great insulin spiking form of sugar.
The carbohydrates that are present in these products and juices produce a rapid surge of blood sugar. Furthermore, they are wiser choices than that of apple, grapefruit, or pear juice6.
Sports drinks, which contain a greater-than-10% carbohydrate concentration of sucrose and maltodextrin effectively elevate the blood sugar. Therefore, these drinks are an excellent post workout choice of carbohydrate providing the insulin spike that the athlete is in search of5,6.
The designers of Gatorade® realized this a long time ago when they formulated the now famous sports replenishment drink.
The ANTF has two key steps. The first step is complete when we have elevated the blood glucose and insulin levels by consuming the previously described replenishment sports drink. Now that the insulin levels are soaring we must add in protein to the concoction, which is the second step.
The sports drink does not have any protein in it; by adding protein to the drink we are supplying protein to the muscles by taking advantage of the insulin surge5.
Adding Whey Protein, an easily digested protein, to the replenishment drink creates an optimal anabolic environment. This will ultimately provide the depleted muscle cells with a highly powerful concoction consisting of glucose and amino acids.
Furthermore, it produces an increase in blood insulin resulting in maximal uptake of glucose and protein2. The glucose will be transported into the muscle cells and locked inside the muscle as glycogen, which will be readily available for energy3.
The protein will stimulate protein synthesis inside the mitochondria of the muscle. Mitochondria are microscopic powerhouses, which energize every human activity. The more mitochondria that a cell possesses the more stamina it will have. Resistance training increases the number of mitochondria in muscle cells7.
The culminating result lies in the fact that the protein and carbohydrate liquid concoction will cease muscle catabolism and increase muscle anabolism3. This would be considered the first of four post-training meals that are to be consumed.
Your SECOND Post-Workout Meal
Consumption of the second post training meal should be conducted about 30 minutes following the initial liquid mixture of carbohydrates and protein. The second meal should be low in fat, to speed gastric emptying, and contain easily absorbed carbohydrates along with a lean source of protein.
The second meal is similar to the first meal in macronutrient composition; however, the food choices are slightly different. At this time the best carbohydrate choices would be a baked potato, steamed white rice, cooked grits, or pasta.
The second meal should be in the form of solid food. The second meal could be a grilled chicken/fish with rice or a serving of meat sauce, made with a lean source of meat, over pasta. Consuming this meal assures that the amino acids from the whey, which was consumed in the first meal will be used for muscle anabolism and not the restoration of blood glucose5.
This meal should not be too large in content. Research shows that cellular anabolic mechanisms remain accelerated for up to three hours following intense resistance training3. The athlete may feel slightly full but not overly stuffed after consuming the second meal.
So far the athlete has consumed a drink and a small meal within a half hour following training. The nutrients must be given a chance to exit the stomach. The meals are kept small but rather powerful attempting to avoid intestinal bloat. A keen eye should be watching the clock because the athlete still has two and a half hours to use their anabolic window of opportunity.
Still Hungry? Your THIRD and FOURTH Post-Workout Meals
After consuming the second meal the athlete should wait about an hour before consuming the third. They still have to consume two more small solid food meals similar to the second. If the athlete feels like eating a solid meal would cause intestinal bloat they could use another serving of whey and consume a small potato.
Athletes can be creative and use any of the other designated carbohydrates but the third meal should be small in content. The athlete now has one and a half hours remaining to consume the fourth and final anabolic meal.
The athlete should use their best judgment on deciding when to consume this meal, but should try to consume it within the last half hour of their anabolic window.
Within the three-hour post-training time frame the athlete will have consumed four small meals. The initial liquid meal and three food meals should have contained about 40 grams of protein and 20-30 grams of carbohydrates each. Utilizing the ANTF allows a steady stream of amino acids to be channeled straight toward the muscle promoting anabolism2,5.
Athletes are concerned with the results associated with their training. The ANTF, which is a great technique, will definitely assist the athlete in making progress. This paper has thus far outlined the details needed to follow the ANTF; and as you can see living by the quote, "timing is everything" is essential when following this nutritional practice.
The Other 21 Hours Of Your Day
There are still 21 hours remaining in the day and the style of eating that should be followed is drastically different than what occurred in the latter phase of the ANTF.
The bulk of the remaining portion of the diet will be built on fibrous vegetables and sources of lean protein. Fibrous vegetables supply the body with vitamins and minerals.
Furthermore, fibrous vegetables elevate your metabolism providing a sustained energy source to the body assisting in fat loss. Additionally, they also allow more volume in the diet while providing only a few kilocalories.
Fiber also slows down gastric emptying assuring proper utilization of the protein consumed and promoting satiety. Fibrous vegetables should be a major component of any healthy diet8.
Management of blood insulin is once again a key component throughout the remainder of the day. Fibrous vegetables have a low glycemic value; therefore, insulin levels are managed efficiently5.
The results are fewer highs and lows associated with energy levels, less mood swings, and less of a chance for fat storage; amazingly the opposite is the case in typical unpredictable diet regimens. Although this paper does not focus on fat loss, which occurs when kilocalorie expenditure exceeds consumption, fibrous based diets allow for fat loss to occur8.
The managing your blood insulin levels is critical in maintaining a natural anabolic drive. The anabolic drive is a synergistic interaction of the growth factors, anabolic hormones, and nutrients, which control muscle anabolism6.
Insulin is a key component in this mixture. Insulin influences every physiologic muscle-building pathway in the human body. Maintaining the anabolic drive revolves around maintaining steady insulin levels7.
Daily food choices completely govern the ability of the body to burn fat and build muscle. Consuming poor food choices following training and taking haphazard approaches to dieting promotes surges and plummets in regards to blood insulin and blood sugar levels.
This interrupts the anabolic drive making the athletic efforts tended to improve performance, useless. Carbohydrate selection can either make or break results.
Contrary to what most people believe fibrous vegetables do supply the body with both fiber and glucose8. For a carbohydrate to be used as energy in the cells they must end up in the form of glucose.
Fiber does not provide energy but has many healthy associations attached to it8. Fiber is a complex structure containing several types of sugar molecules. The body cannot digest fiber due to a lack of the digestive enzymes, which are required to break the bonds that bind the sugar molecules together. Thus, fiber passes though the digestive system in an undigested form.
The Glycemic Index Of Carbs
Carbohydrates should be thought of as either high or low glycemic. Carbohydrates and their association to insulin have a huge impact on health issues. Scientists investigated the physiological response of foods defining the increase in blood sugar levels created by each.
The glycemic index (GI) ranks foods based on the immediate effect they have on blood glucose. The GI ranks foods on a 0 to 100 scale related to the extent that the food raises the blood sugar. Quickly broken down carbohydrates have high GI ratings.
Slowly broken down carbohydrates, gradually release glucose into the blood and have a low GI rating5. These ratings associated with fibrous vegetables and are the type that should be consumed throughout the remainder of the day. Low GI foods slow down digestion and absorption producing gradual rises in blood insulin and blood glucose.
When you select foods keeping the GI rating in mind you decrease the overall amount of insulin secretion while promoting insulin sensitivity in tissues. This makes insulin more effective when present in the body.
Dr. David Jenkins developed the GI in 1981. It was designed for a diabetic aid during food selection in attempt to promote insulin management5. For athletes, having knowledge of the GI ratings of carbohydrates can be a valuable tool.
Following the post-training ANTF period, optimal nutrient transport and maintenance of steady blood insulin and glucose levels can be achieved by selecting from GI foods, which possess a rating below 60. Low GI carbohydrates in general are unrefined foods as are fibrous vegetables.
These foods maintain an optimal anabolic environment through managing blood glucose and insulin keeping them within a tight range. These carbohydrates prevent hunger pangs and slumps of energy while promoting fat loss.
When protein is combined with carbohydrate foods having a higher GI rating, they have the ability to lower the overall GI rating of the meal. Mother nature intended our diets to be glycemically low. Protein foods are all low on the GI. All the nutrients that we need were generally packaged for us in a slow release form via fibrous vegetables.
Modern technology toyed with mother nature's version of foods for pleasure and shelf storage reasons. Processing foods makes them higher on the GI scale. The effects of the instant and artificial foods are revealed through the prevalence of diabetes, heart disease, obesity, and weight gain.
Being aware of carbohydrate types and knowing when to eat them will accelerate results from an athletes training. The foods selection outlined in the ANTF is the one time when selecting foods with a high GI will promote training results. It is recommended that athletes keep their total carbohydrate intake at about 40% of their total caloric intake.
This will provide an adequate amount of fuel for their muscles and allow other bodily functions to adequately operate while preventing the intake of excess carbohydrates, which would result in a conversion of body fat.
Fat And Protein Intake
Having covered carbohydrates leaves two other macronutrients yet to be covered. Carbohydrates, fat, and protein all play a synergistic part in an athlete's performance. However, a basic rule in general still stands to prove that it is dietary protein that supports muscle growth, maintenance, and recovery.
Carbohydrates and fats, while having a significant role in the athlete's diet do not have any muscle growth properties associated with them. It is protein, which supplies the essential amino acids needed to support muscle anabolism.
Before going in to the specifics of protein requirements let us take a look at the composition of a daily diet. The three macronutrients, protein, carbohydrates, and fats make up the total caloric intake of every healthy diet.
Carbohydrates are converted into glucose and are used to supply the muscles with energy and support adequate brain function9. Fats are a dense source of energy containing 9 calories per gram, which is over two times of what protein and carbohydrates supply.
Because of the density you can meet your daily caloric limit quite quickly via high fat foods. Fats are a necessity and support many vital bodily functions. However, you do not require very much of it and most people consume more dietary fat than is actually needed.
When athletes follow a diet that is high in lean protein sources and moderate in carbohydrate intake, fat consumption generally takes care of itself. For specifics, fat intake should remain around 10% of an athlete's total caloric intake. This amount allows for the necessary functions which fat provides and limits excess kilocalories associated fat consumption8.
Protein is required for virtually every growth promoting process. Protein is a cellular builder, and besides water, protein is the most abundant substance in the human body.
Protein has presence in every organ and is an essential nutrient for the production of blood, hormones, and enzymes. Additionally, protein is essential for immunologic factors, muscle repair, maintenance, and growth10.
Athletic training, particularly resistance training, places an increased demand for protein in the athlete. When athletes train and eat properly they will build muscle tissue and the more muscle developed the more protein that is required. Muscle tissue is the primary deposit site for protein.
Muscle is like a protein reservoir and if you supply an insufficient amount of protein to your body it will take amino acids from muscle tissue when needed11. This is known as muscle catabolism, which is something that every athlete wants to avoid.
From briefly covering the importance of the three macronutrients nutrients you should understand why heavy emphasis is placed on protein consumption when referring to athletes. Protein is largely utilized in the growth processes for athletes trying to develop muscle and increase performance.
Therefore, it is essential that at least 50% of an athlete's daily kilocalories be supplied from dietary protein. Paul Delia, the founder and president of AST Sports Science, recommends at least 1.9875 grams of protein to be consumed for every pound of an athlete's body weight10,12.
ANTF: An Example
This nutritional approach can be wrapped up and summarized through the use of an example. Let us say that there was a 150-pound bodybuilder that wanted to use the ANTF. The bodybuilder had been keeping an extensive food diary and knows that he consumes about 2500 kilocalories every day.
The bodybuilder should consume 312 grams of protein each day, which is 50% of the total kilocalories. Carbohydrate consumption should consist of 40% of the total kilocalories, which equates to about 250 grams a day. Finally fat, which should comprise of about 10% of the total kilocalorie intake calculates to 28 grams a day13.
If the bodybuilder eats four meals containing 40 grams of protein and 30 grams of carbohydrates in the three-hour post-training window of opportunity he has consumed 160 grams of protein and 120 grams of carbohydrates.
This equates to 45% of the total daily kilocalories. The bodybuilder still has 172 grams of protein, 130 grams of carbohydrates, and roughly 25 grams of fat to be consumed over the remaining 21-hour period.
The bodybuilder can easily get the remaining kilocalories via four small meals containing 43 grams of protein, 32 grams of carbohydrates, and 6 grams of fat. I chose to include this example for the athletes that are number specific.
However, I believe that it is more important to understand that the type, quality, and timing is far more critical than the numbers when attempting to create an anabolic effect14.
The precise calculations are interesting and are supported by science, but the truth of the matter lies in the fact that the typical athlete will not be as concerned as are the elite few. Some determined athletes are willing to keep logs and journals documenting their nutritional and training habits.
Nonetheless, the concept of the ANTF is remarkable. If the medical community, because of their lack of understanding, chooses to dispel it as a fad this would shed disgrace on the intellectual athletic community. These people are the pioneers of athletic performance research, whom are forever seeking new breakthroughs in all fields of sport-associated sciences.
- Yakar S, Liu JL, Fernandez AM, et al. Liver-specific igf-1 gene deletion leads to muscle insulin insensitivity. Diabetes, 2001; 50:1110-1119.
- Wolfe R. Insulin action on muscle protein kinetics and amino acid transport during recovery after resistance exercise. Diabetes. 1999; 48:949-957.
- Rasmussen B. An oral essential amino acid-carbohydrate supplement enhances muscle protein anabolism after resistance exercise. J. Appl. Physiol. 2000; 88:386-392.
- Bolio GY. An abundant supply of amino acids enhances the metabolic effect of exercise on muscle protein. Am.J.Physiol. 1997; 273:E122-E129.
- Gastaldelli A, Toschi E, Pettiti M, et al. Effect of physiological hyperinsulinemia on gluconeogenesis in nondiabetic subjects and in type 2 diabetic patients. Diabetes, 2001; 50:1807-1816.
- Cribb P. The anabolic nutrient timing factor: the real science behind building muscle mass without drugs. AST Sports Sci. http://www.ast-ss.com/articles/article.asp?AID=77. 02 Jan 2003.
- Choi C. Gain without pain. Scientific American, 2002; 286:28-31.
- Position of the American Dietetic Association: health implications of dietary fiber. JADA, 2002; 102:993-998
- Mathews ST, Singh GP, Ranalletta M, et al. Improved insulin sensitivity and resistance to weight gain in mice null for the Ahsg gene. Diabetes. 2002; 51:2450-2459.
- Masanes RM, Rafecas I, Remesar X. Splanchnic amino acid balance is affected by moderate variations of dietary protein in the developing Zucker rat. International Journal of Food Sciences and Nutrition, 2001; 52:183
- Miller BJ, Powell KF, Colagiuri S. The GI Factor- The Glucose Revolution. Sydney, Australia: Hodder Publishing Inc. 1998.
- Delia P. Paul Delia's hard core Q&A. AST Sports Sci. http://www.ast-ss.com/dev/qa_search/full_text.asp?ID=67. 02 Jan 2003.
- Delia P. Max-OT training series. AST Sports Sci. http://www.ast-ss.com/max-ot/course/week4/week4_max9.asp. 02 Jan 2003.
- Millward DJ, Rivers HP. The concept of the anabolic drive. Diabetes Metab Rev. 1989; 5:191-211.