Changes in Intra-to-Extra-Cellular Water Ratio and Bioelectrical Parameters from Day-Before to Day-Of Competition in Bodybuilders: A Pilot Study

Abstract

The present study analyzed the effects from day-before to day-of bodybuilding competition on intracellular water (ICW), extracellular water (ECW), total body water (TBW), and bioimpedance analysis (BIA) parameters (resistance, R; reactance, Xc; and derived scores) in bodybuilding athletes. We assessed anthropometry and BIA (foot-to-hand; tetrapolar; 50 kHz) in 11 male bodybuilders (29 ± 4 year-old; 81 ± 8 kg; 172 ± 7 cm; 27 ± 2 kg/m2) both on the pre-competition day and on the contest day. Results revealed significant increases in ICW (31.6 ± 2.9 to 33.1 ± 2.8 L), with concomitant decreases in ECW (19.8 ± 1.8 to 17.2 ± 1.4 L) and TBW (51.4 ± 4.6 to 50.3 ± 4.2 L) from the day-before competition to contest day, which resulted in relatively large increases in the ICW/ECW ratio (1.60 ± 0.03 to 1.92 ± 0.01 L). Moreover, significant increases in R (391 ± 34 to 413 ± 33 ohm), Xc (64 ± 7 to 70 ± 6 ohm), and phase angle (9.3 ± 0.6 to 9.6 ± 0.7 degree) were observed between time periods. The phase angle scores reported on show-day of 9.6 and 11.2 appear to be the highest group mean and individual values observed in the literature to date. In conclusion, the strategies carried out on the final day of peak-week bodybuilding preparation lead to changes in BIA parameters and body water, with fluids shifting from the extra- to the intracellular compartment.

Can Bodybuilding Peak Week Manipulations Favorably Affect Muscle Size, Subcutaneous Thickness, and Related Body Composition Variables? A Case Study

“…The outcomes observed throughout this investigation provide further insight to the physiological impacts to specific bodybuilding peaking strategies. Some of the data are supported by previous studies [ 5 , 6 , 11 ] while other results demonstrate novel findings that have not been formally examined to date. Previous research has shown that bodybuilders implement a variety of peaking strategies with the aim of enhancing body composition, maximizing muscle size, and minimizing the interstitial space/subcutaneous thickness [ 4 ]; however, the success rate and physiological impact of these strategies are not well established.…”

“…Interestingly, ~83% of the increases in TBW were estimated to be stored as ICW (+1.75 L), which improved the ratio between ICW and ECW from one day out (1.55) to competition morning (1.61). Although it is difficult to explain these favorable acute changes, recent data from a cohort of 11 male bodybuilders demonstrated similar results [ 6 ]. Nunes et al [ 6 ] demonstrated positive changes in ICW:ECW from one day out to competition day, however, they also observed reductions in TBW and ECW (which is what we hypothesized but did not observe).…”

“…Although it is difficult to explain these favorable acute changes, recent data from a cohort of 11 male bodybuilders demonstrated similar results [ 6 ]. Nunes et al [ 6 ] demonstrated positive changes in ICW:ECW from one day out to competition day, however, they also observed reductions in TBW and ECW (which is what we hypothesized but did not observe). Unfortunately, the dietary practices employed by those 11 competitive bodybuilders was not reported so comparisons cannot be made.…”

“…Whereas the ‘contest prep’ phase (often 8–24+ weeks) is primarily focused on reducing body fat to extreme levels for competition [ 2 , 4 , 5 ]. Despite the majority of the work and preparation taking place over a long period of time well before competition day itself, the final phase, ‘peak week’, can certainly improve or hinder the physique athlete’s aesthetics [ 4 , 5 , 6 ].…”

“…Until recently, there were a lack of objective data demonstrating whether bodybuilders were successful at manipulating the intracellular-to-extracellular water ratio to enhance their physique and peak for the competition. A recent pilot study [ 6 ] reported that physique athletes were able to successfully alter fluid from the extracellular to the intracellular compartment the final day of peak week. Their bioimpedance analysis revealed a ~1.5 L increase in intracellular water, a ~2.6 L decrease in extracellular water, which resulted in large and favorable increases to the intra-to-extra-cellular water ratio (1.60 to 1.92).…”