VALIDATION OF SELECTED ANTHROPOMETRIC REGRESSION EQUATIONS FOR BODY COMPOSITION ASSESSMENT OF MALE UNIVERSITY ATHLETES IN SOUTH WESTERN NIGERIA

Abstract

Body composition assessment of athletes is acknowledged as basic physiological determinant of athletic health and performance. Assessment of body composition of male Nigerian University athletes, using foreign-derived anthropometric regression equations usually brings with it the issue of precision, accuracy and validity. Previous studies largely focused on developing and validating commonly used equations among foreign athletes, but little research efforts have been directed towards validating these equations on Nigerian athletes using the Underwater Weighing (UWW) criterion. This study, therefore, was carried out to validate the selected anthropometric equations. The study was anchored to the Theory of Human Body Composition Assessment, while the ex-post facto design was employed. The equations validated were Brozek and Keys (BK) 1951, Sloan and Weir (SW) 1970, Sinning (SI) 1974, Forysth and Sinning (FS) 1975, and Jackson and Pollock (JP) 1979 in order to confirm or refute their respective validity on body composition assessment of male university athletes in Southwestern Nigeria. The multistage sampling procedure was used. Three first generation federal universities in Ibadan, Lagos and Ile Ife) were enumerated, using the intact group of endurance athletes (45), power athletes (45) and control group (45) in each University. The instruments used were UnderWater Weighing equipment, spirometer, health-o-meter scale and skinfold calipher. Underwater measurements were taken following Barton and Cameroon (2009) procedure, while skinfold measurement of abdominal, chest, triceps, subscapular, suprailiac, and thigh were taken following ISAK (2011) protocol. Data were analysed using descriptive statistics, Pearson product moment correlation, t-test, and multiple regression at 0.05 alpha level. Participants’ age was 24.06±2.25 years. There was no significant difference in physical characteristics of height, body weight and body density of endurance athletes, power athletes and control group, but they significantly differed in percent fat and lean body weight. There was moderate, positive, relationship between Body Density (BD) of UWW and BD of BK, SW, SI, FS, but JP(r=0.77) was strongly significantly related. There was positive, relationship between %bf of UWW and %bf of BK(r=0.27), SW(r=0.26),vi SI(r=0.18), FS(r=0.38) except JP(r=0.72). There was significant difference between BD determined by UWW and BD of BK(t=-12.33), SW(t=-16.21), SI(t=-11.58), FS(t=-7.75) and JP(t=-2.92). There was also a significant difference between %bf of UWW and %bf of BK(t=10.22), SW(t=14.95), SI(t=11.66), FS(t=6.34) and JP(t=8.00). Plotted against validation criteria of Multiple Correlation Co-efficient (R), Constant Error (CE), Total Error (TE), Standard Error of Estimate (SEE), the values obtained were BK(R2=.103, CE=-0.02, TE=0.002, SEE=0.004), SW(R2=.103, CE=0.02, TE=.003, SEE=.006), SI(R2=.138, CE=-0.02, TE=0.002, SEE=0.01), FS(R2=.209, CE=0.01, TE=0.002, SEE=0.006), JP(R2 =.208, CE=-0.02, TE=0.002, SEE=0.002). All the examined equations failed the validity test. As a credible alternative this equation was formulated: BD=1.064+0.00392 (X1)+0.669 (X2)+0.07761 (X3). The anthropometric regression equations of Brozek and Keys, Sloan and Weir, Sinning, Forsyth and Sinning (1975), and Jackson and Pollock, have relationship with, but are significantly different from underwater weighing. All the equations overestimated Body Density and underestimated percent body fat in male University athletes in Southwestern Nigeria. The validated prediction equations should be used with relative caution, while the equation formulated needs to be adopted by Nigerian male athletes.