The topic of water and sodium manipulation during peak week is arguably the most controversial in bodybuilding. Many coaches and competitors advocate for water depletion to achieve that “paper-thin” skin look, but these practices can be dangerous and have contributed to bodybuilding’s negative image. This article specifically addresses natural bodybuilding, excluding those using performance-enhancing drugs that cause water retention.
Two main schools of thought exist within the natural bodybuilding community. One suggests avoiding water cuts entirely, while the other advocates for manipulating water and/or sodium for optimal stage appearance.
Understanding the body’s water compartments is crucial. Roughly two-thirds of our body water resides intracellularly, within the cells. The remaining third is extracellular fluid, divided into interstitial fluid (between cells and blood vessels), plasma water (in blood vessels), and a negligible third space. Bodybuilders aim for high intracellular fluid for muscle fullness and high plasma water for vascularity. It’s the interstitial space, specifically the small amount under the skin, that’s targeted for depletion.
The skin has several layers. The outermost stratum corneum and epidermis are negligible in this context. The dermis, ranging from 0.5mm to 3mm thick, is the layer of concern. Beneath the dermis lies subcutaneous fat, which is shed during contest prep. The dermis itself is 70-75% water, meaning even a maximal reduction only yields a small change in thickness. The idea of a substantial subcutaneous water layer is a myth perpetuated by supplement advertisements.
Sodium manipulation is often attempted, but depleting dietary sodium is ineffective. The body tightly regulates blood sodium levels, as evidenced by a 1990 Harvard study where drastically reducing dietary sodium didn’t significantly change blood levels. Furthermore, low sodium combined with high water intake risks hyponatremia. Depleting sodium also hinders glucose absorption into muscles, counteracting the desired full look.
Sodium loading, however, can be beneficial. Chronically loading sodium for extended periods can cause edema, but acute loading can increase vasodilation, enhancing vascularity. A 1995 study suggested that salt loading increases nitric oxide production, promoting vasodilation. Therefore, maintaining a moderate sodium intake throughout prep, followed by a significant increase on show day or the night before, is recommended.
Traditional water depletion strategies aim to reduce the perceived subcutaneous water layer. However, this indiscriminately reduces water from all compartments, including intracellular and plasma water, leading to a flat appearance.
Two alternative strategies exist: dry carb loading and leveraging cutaneous transpiration. Dry carb loading involves reducing water intake while drastically increasing carbohydrate intake, theoretically pulling water into the muscles while flushing extracellular fluid. Cutaneous transpiration, the movement of water through the dermis and off the skin, accounts for a small amount of daily water loss. While methods to increase this are unclear, staying warm leading up to the competition might be beneficial.
Two important hormones, anti-diuretic hormone (ADH) and aldosterone, regulate water and sodium balance, respectively. Both have short half-lives, meaning their levels adjust rapidly. This renders pre-contest water loading largely ineffective, as ADH and aldosterone levels will quickly adapt upon water reduction.
Two conservative water manipulation protocols are recommended. The first involves maintaining consistent water intake throughout peak week and on show day. The second involves a slight decrease in water intake on Friday evening, coinciding with a significant carbohydrate increase (dry carb loading). The first protocol is generally preferred due to its lower risk of flattening out.
For sodium, maintain a consistent intake throughout peak week, followed by a significant increase on Friday night or Saturday morning. This can be achieved by consuming sodium-rich foods or simply adding more salt to meals. Experimentation is key to finding the optimal timing and amount.
Peak week is often overemphasized. Consistent dieting, training, and cardio are the primary drivers of a successful physique. While carb and sodium manipulation can refine the final look, drastic measures are unnecessary and potentially harmful. Prioritizing health and enjoying the process should always be paramount.
