Raw Bioelectrical Impedance Analysis Variables (Impedance Ratio and Phase Angle) and Physical Fitness in Cross-Fit® Athletes

Few data are available on body composition and its relationships with physical fitness in Cross-Fit (R) athletes. Our study aimed to evaluate changes in raw bioelectrical impedance analysis (BIA) variables and their relationships with physical fitness in male Cross-Fit (R) athletes. Fifteen male Cross-Fit (R) athletes (age 19-35 years, weight 83.8 +/- 5.6 kg, body mass index-BMI 26.0 +/- 1.9 kg/m(2)) and fifty-one control men, (age 20-30 years, weight 76.5 +/- 10.8 kg, BMI 24.6 +/- 3.2 kg/m(2)) participated in the study. Body composition was evaluated by using BIA and physical fitness was assessed by measuring handgrip strength (HGS), long jump (L-J), squat jump (SQ-J) and counter-movement jump (CM-J). Phase angles were higher and impedance ratios were lower in Cross-Fit (R) athletes for the whole body and limbs (both these directly-measured raw BIA variables are promising markers of muscle quality). HGS was only slightly higher in the Cross-Fit (R) group, whereas a clear difference emerged between groups in L-J (+16.2% in Cross-Fit (R) athletes), SQ-J (+21.5%) and CM-J (+21.5%). HGS, L-J, SQ-J and CM-J significantly correlated with both impedance ratios and phase angles (for whole body and limbs). In conclusion, raw BIA variables such as impedance ratio and phase angle significantly change in Cross-Fit (R) athletes compared to controls and also exhibit significant relationships with physical fitness.