Izvorni znanstveni članak
Nonlinear Relationships between Anthropometric and Physical Fitness Variables in Untrained Pubescent Boys
Nataša Zenić
; University of Split, Faculty of Kinesiology, Split, Croatia
Nikola Foretić
; University of Split, Faculty of Kinesiology, Split, Croatia
Mateo Blažević
; University of Split, Faculty of Kinesiology, Split, Croatia
Sažetak
Previous studies evidently actualized nonlinear regressions as a step forward in defining the true nature of the relationships between anthropometric and physical fitness (PF) variables in trained subjects. In this paper we have sampled 1176 nontrained boys aged 14–16 years and tested them on (1) five anthropometric predictors, including: body height, body weight, triceps skinfold, upper arm circumference, and body mass index (BMI); and (2) five PF criteria measuring: static (static strength) and dynamic muscle endurance (repetitive strength), aerobic endurance, explosive strength, and
coordination. Linear (y = a + bx) and nonlinear (second-order polynomial: y = a + bx + cx2) regressions were calculated
simultaneously. BMI is found to be the most significant anthropometric predictor of PF status. Although the calculation and interpretation of nonlinear regressions are far more complicated in comparison to those of linear regressions, the variance of the criteria are in some cases far better explained through a significant nonlinear model. Even more, we have found evidence that an exclusive discussion of the linear correlation model could lead to serious interpretative mistakes. This mostly relates to the fact that a linear regression model implies a continuous relationship (dependence) between the predictor and the criteria, while a nonlinear one effectively identifies possible breakpoints in the regression line and consequently highlights the real nature of the relationship between variables.
Ključne riječi
nonlinear regressions; anthropometry; physical fitness; testing
Hrčak ID:
102473
URI
Datum izdavanja:
23.5.2013.
Posjeta: 1.064 *