ABSTRACT

BODYBUILDING s a competitive endeavor where a combination of muscle size, symmetry, “conditioning” (low body fat levels), and stage presentation are judged. Success in bodybuilding requires that competitors achieve their peak physique during the day of competition. To this end, competitors have been reported to employ various peaking interventions during the final days leading to competition. Commonly reported peaking strategies include altering exercise and nutritional regimens, including manipulation of macronutrient, water, and electrolyte intake, as well as consumption of various dietary supplements. The primary goals for these interventions are to maximize muscle glycogen content, minimize subcutaneous water, and reduce the risk abdominal bloating to bring about a more aesthetically pleasing physique. Unfortunately, there is a dearth of evidence to support the commonly reported practices employed by bodybuilders during peak week. Hence, the purpose of this article is to critically review the current literature as to the scientific support for pre-contest peaking protocols most commonly employed by bodybuilders and provide evidence-based recommendations as safe and effective strategies on the topic

Carbohydrate Manipulation

Manipulation of carbohydrate intake is a popular pre-contest peaking strategy among bodybuilders. The strategy, generally employed during the week prior to competition, involves substantially limiting carbohydrate intake for several days (often referred to as depletion phase) followed by a brief period of high-carbohydrate consumption, with the goal of achieving a supercompensation of glycogen levels when carbohydrate is “loaded”. Resting muscle glycogen levels with a mixed (normal) diet are ~ 130mmol/kg muscle (wet weight) in trained individuals (a bit higher than sedentary subjects), or roughly 23 g of glycogen (glucosyl units) per kilogram of muscle tissue. Muscle glycogen is organized in the cell in subcellular fractions and stored as a glycogen-glycogenin complex (“granule”) which creates an osmotic effect of pulling water into the cell as glycogen is stored, thereby increasing muscle cell volume. Early research suggested that each gram of muscle glycogen stored is accompanied by approximately 3–4 g of intracellular water. This is higher than the commonly referenced value of 2.7 g of water per gram of glycogen, sometimes rounded to 3 g of water per gram of glycogen, which is derived from studies of rat liver . However, the resultant muscle glycogen levels after glycogen loading is highly variable, perhaps due to the complexity underlying intramuscular glycogen storage . Similarly, while it is clear that glycogen loading can increase intracellular water content, muscle thickness, and lean body mass (LBM) estimates, the relative extent of intracellular hydration in grams of water per gram of glycogen may vary so greatly that it is not statistically correlated with glycogen content.

WATER AND SODIUM MANIPULATION

Water and sodium are frequently manipulated by bodybuilders, either independently or concurrently, employing a variety of strategies involving “loading” and restricting both, with the goal of minimizing subcutaneous water to maximize the underlying skeletal muscle definition. Bodybuilders may also employ these strategies to drop down to lower weight classes, which can provide a competitive advantage if the competitor is able to regain some of weight in the form of intramyocellular volume (“filling out” via glycogen and/or intramyocellular triglyceride storage) prior to competition. Although water and sodium are two separate dietary components, it is critical to comprehend that manipulation of one variable influences the other; hence, we will review these two variables together.

100 % of participants utilized the practice of water loading and water cutting during peak week. This strategy involved drinking 10 L of water per day early in the week and then reducing the intake each subsequent day leading up to the competition. The theory behind this practice was to consume superfluous amounts of water to naturally increase fluid excretion in an attempt to preferentially excrete subcutaneous water. SOME participants that manipulate water during peak week, also manipulate sodium to help remove subcutaneous water. They reported greatly increasing sodium intake for the first three days of peak week followed by a complete restriction of salt intake for the three days prior to the competition.

Despite the various strategies reported by bodybuilders to manipulate water and sodium for the purposes of looking “full and dry,” current evidence does not indicate that these practices are specifically effective and/or safe. Additionally, although several water and sodium manipulation strategies have been published by a number of bodybuilding coaches who have worked with highly successful bodybuilders, neither the efficacy nor safety of these varying methodologies have been scientifically evaluated. Hence, physiological principles of body fluid regulation must be considered when attempting to formulate strategies to promote a “full and dry” appearance, and these strategies may be discordant with those currently used by bodybuilders and/or suggested by their coaches.

Total body water (TBW) content accounts for approximately 60 % of an average person’s body weight and is made up of intracellular water (ICW) (~ 67 %) and extracellular water (ECW) (~ 33 %). ECW is further compartmentalized into interstitial fluid that surrounds the cells (~ 25 %) and blood plasma (~ 8 %). Hence, from a bodybuilder’s perspective, minimizing the extracellular interstitial fluid that surrounds the myocytes, specifically subcutaneous water, while preserving or increasing the intramyocellular ICW represents the ideal scenario for a “full and dry” appearance, i.e., whereby the appearance of muscularity is maximized. While this concept may seem like a simple task to accomplish by manipulating water and sodium alone, other strategies focused on optimizing intramyocellular volume (i.e., those targeting intramyocellular glycogen, triglyceride, and potassium content) may need to be considered along with the manipulation of water and sodium for the appearance of muscularity to be enhanced.

manipulation of water and sodium should be carefully considered, planned, and practiced in conjunction with carbohydrate manipulation if they are to be utilized. While there appear to be some potential benefits to implementing these strategies to enhance the competition-day physique, potentially detrimental/ADVERSE effects may occur if these variables are miscalculated and/or mistimed that may cause bodybuilders to miss their peak and/or incur health problems; thus, leaving these variables alone may be a better option for some competitors. Since bodybuilders have been reported to view sodium and water manipulation as temporary but necessary practices while downplaying the potential risks involved, caution must be practiced. The practical applications sections of this article will further outline how these variables may be safely manipulated based on the current evidence available.

DIETARY FAT

In addition to glycogen, muscle cells also store energy as intramuscular triglycerides. Indeed, nearly as much energy is stored in muscle cells as IMT as is stored as glycogen. However, IMT stores vary considerably in humans, in part as a function of training status, muscle fiber type, insulin sensitivity, gender, and diet. IMT may amount to ~ 1 % of muscle weight, but because fat is less dense than skeletal muscle, the volume of IMT in a fully “fat-loaded” muscle cell could exceed 2 % of muscle volume. In rats, a single exercise bout can decrease muscle IMT content by 30 %, and three days of a high fat diet can boost IMT storage by ~ 60 % above baseline. In humans, the dietary replenishment of IMT may be slower when glycogen restoration is also a priority. Still, IMT stores are increased by dietary fat intake and reduced during resistance and endurance exercise.

Although fat loading has been a known strategy in bodybuilding circles for many years, to our knowledge the strategy has not been studied directly in a bodybuilding peak week context (e.g., in combination with other dietary strategies such as glycogen supercompensation). In the rodent study mentioned above, three days of a high fat diet followed by three days of a high carbohydrate diet resulted in supercompensation of both IMT and glycogen; however, 6 days of only a high CHO produced the expected glycogen loading effect but failed to elevate IMT levels above baseline. In humans, high CHO/low fat diets may actually precipitate a reduction of IMT stores, perhaps because IMT is used preferentially to cover the energetic costs of post-exercise cellular repair and glycogen-glycogenin assembly. Considering that a large (e.g., heavyweight male) bodybuilder may carry over 60 kg of muscle, increasing IMT stores from a relatively “depleted” to a “loaded” state could conceivably increase muscle volume by 1 % ; hypothetically, this translates to adding 0.6 kg of fat free mass. Hence, fat loading appears to be a promising strategy to be used in conjunction with CHO loading during peak week for bodybuilders, and thus warrants future study in a controlled setting.

DIETARY PROTEIN

n conjunction with carbohydrate and fat intake during peak week, optimizing protein intake warrants discussion, as it is a major and indispensable component of the diet. protein requirements are inversely proportional to energy intake AND has special significance for athletes in prolonged hypocaloric conditions, epitomized by pre-contest physique competitors. In light of mounting evidence, a daily intake of 1.2–1.6 g/kg has been proposed as optimal for the general population aiming to optimize health and longevity within a physically active lifestyle. Toward the more athletic end of the spectrum, in the most comprehensive meta-analysis of its kind found that a protein intake of ~ 1.6 g/kg (upper 95 % CI of 2.2 g/kg) maximized muscle hypertrophy and strength in non-dieting recreational resistance trainees.

A potential consideration for protein dosing during peak week is whether to keep protein intake static or alter it during the carbohydrate depletion and loading phases. an increase in muscle volume and enhanced physical appearance as a result of a carbohydrate-loading protocol provides some evidence that bodybuilders alter their protein intake during peak week. the depletion/loading protocol was three days of a low-carbohydrate (1.1 g/kg) and high-protein (3.2 g/kg) diet followed by only one day of a high-carbohydrate (9.0 g/kg) and low-protein (0.6 g/kg) diet.

A potentially viable strategy of altering protein intake during peak week is to keep protein intake relatively high at ~ 2.5–3.5 g/kg/day during the initial ~ 3 days of glycogen depletion portion of a glycogen super compensation strategy, followed by a relatively lower protein intake of ~ 1.6 g/kg/day during a high carbohydrate diet for 1–3 days finishing at least 24 h before the scheduled competition. Thereafter, a strategy for inducing diuresis and (further) elevating IMT stores during the day preceding competition by following a high protein, low carbohydrate (high fat) diet for a short period (~ 12–24 h) could be employed. As previously discussed, when carbohydrate loading using a low fat approach, IMT levels may decline, but elevated glycogen levels persist for several days in lieu of glycogen-reducing, demanding contractions (e.g., resistance exercise or excessive posing). High levels of intramuscular glycogen and the associated intracellular water would thus prevent the loss of ICW that typically accompanies diuresis. Increasing protein intake consumed the day before the show, or simply consuming protein at the high levels typically employed by pre-contest bodybuilders (~ 3.0–3.5 g/ kg / day) and shown recently to be generally safe over longer periods, will encourage greater oxidative deamination of amino acids and ureagenesis that approximate the maximal rates observed in healthy individuals. Clearance of blood urea in turn requires an osmotic gradient during its renal excretion, thus causing diuresis. Additionally, reverting back to a lower carbohydrate diet (e.g., one similar to that used early in the week to fat load in preparation for carbohydrate loading) would also promote loss of body water Thus, increasing or maintaining a high protein intake while lowering carbohydrate and concomitantly increasing fat intake during the day before competing would reverse unwanted gains in extracellular/subcutaneous water experienced during carbohydrate loading. It would also complement other strategic measures designed to induce diuresis such as manipulation of water/sodium/potassium intake, dietary supplementation, and body positioning that would also afford a second opportunity for fat loading during peak week.