Body composition measured by multi-frequency bioelectrical impedance following creatine supplementation

Area of Science:

• Exercise Physiology
• Nutritional Biochemistry
• Body Composition Analysis

Background:

• Acute fluid intake can elevate body fat percentage (BF%) estimates from bioelectrical impedance analysis (BIA).
• The impact of creatine supplementation, known to cause fluid retention and increase fat-free mass (FFM) and total body water (TBW), on multi-frequency bioelectrical impedance (MF-BIA) accuracy is unclear.

Purpose of the Study:

• To evaluate the accuracy of a multi-frequency bioelectrical impedance (MF-BIA) device (InBody 770) in measuring total body water (TBW) and body composition after creatine supplementation.
• To analyze the effects of creatine monohydrate on body composition and TBW.

Main Methods:

• A randomized controlled trial involving 27 participants (13 male, 14 female, aged 18-22 years) receiving either creatine monohydrate or maltodextrin for one week.
• Body composition, including BF%, FFM, and fat mass (FM), was assessed using dual-energy X-ray absorptiometry (DEXA), single-frequency BIA (SF-BIA), and MF-BIA (InBody 770).
• Total body water (TBW), intracellular water (ICW), and extracellular water (ECW) were estimated via MF-BIA.

Main Results:

• The creatine group exhibited significantly greater increases in FFM compared to the placebo group across all measurement methods (SF-BIA, MF-BIA, DEXA).
• Creatine supplementation led to a statistically significant 2% increase in TBW as measured by the InBody 770 MF-BIA device.
• Significant increases in FFM were observed in the creatine group, attributed to increased TBW.

Conclusions:

• One week of creatine supplementation effectively increases TBW, which is accurately detected by the InBody 770 MF-BIA device.
• The observed increases in FFM following creatine supplementation, as measured by SF-BIA, MF-BIA, and DEXA, are influenced by the rise in TBW.