Head above water weighing: A valid method to measure body fat storage?

Hydrostatic weighing using underwater weighing with full lung expiration has been established as a valid method to assess body composition; however, many people do not prefer to submerse their heads in water due to various reasons. Keeping the head above water as a method for hydrostatic weighing at full lung capacity has been tested but has not been accepted as an alternative method. Purpose: The main purpose of this study is to determine if hydrostatic weighing with the head above water at residual volume could provide valid estimates of total body fat. Methods: Fifty-eight subjects (F=29. M=29) participated in performing four different methods of underwater weighing: complete immersion with full lung expiration (UWWRV), complete immersion with total lung capacity (UWWTLC), partial immersion with the head above water at full lung expiration (HAWRV), and partial immersion with the head above water at total lung capacity (HAWTLC). Bland-Altman Plots were created and regression analyses were used to test for proportional bias across the range of means. Results: There was no significant difference between HAWRV and UWWRV for both males and females. However, a Bland-Altman plot indicated the range of error between these methods was \u3e5% body fat for both genders. There was a significant difference between HAWTLC versus HAWRV in both males (t = 4.616, df= 28,