A Body Composition Comparison of Functional Muscle Quality and Jump Mechanics in Collegiate Women
Faculty Mentor Information
Dr. Joshua Bailey (Mentor), University of Idaho; and Dr. Ann Brown (Mentor), University of Idaho
Abstract
The classification of normal weight (BMI = 18.5 – 24.9 kg/m2) has been found to misidentify percentages of fat and lean mass within this population. Using body fat percentage acquired from Dual-energy X-ray absorptiometry (DXA), participants were further classified as lean (< 30% fat) or obese (> 30% fat). The purpose is to assess potential differences in muscle function and jumping mechanics in women classified as normal weight lean and normal weight obese. 16 participants (8 Normal Weight Lean, 3 Normal Weight Obese, and 5 Overweight-Obese) were classified according to their BMI and DXA body Fat % classifications. Rectus Femoris anatomical cross-sectional area (ASCA) was measured using a B-mode ultrasound transducer. Knee extensor strength was assessed using a Cybex Humac Norm at two angular velocities (60 and 120 degrees/sec). Functional muscle quality was calculated for right and left legs as the peak torque (Nm) at each angular velocity divided by the ACSA (Nm/cm). Countermovement jumps were performed in a double and single leg condition, with the task instructions to jump as high as possible. The difference in functional muscle quality between the NWO group and the other two groups was due to strength, not ACSA.
A Body Composition Comparison of Functional Muscle Quality and Jump Mechanics in Collegiate Women
The classification of normal weight (BMI = 18.5 – 24.9 kg/m2) has been found to misidentify percentages of fat and lean mass within this population. Using body fat percentage acquired from Dual-energy X-ray absorptiometry (DXA), participants were further classified as lean (< 30% fat) or obese (> 30% fat). The purpose is to assess potential differences in muscle function and jumping mechanics in women classified as normal weight lean and normal weight obese. 16 participants (8 Normal Weight Lean, 3 Normal Weight Obese, and 5 Overweight-Obese) were classified according to their BMI and DXA body Fat % classifications. Rectus Femoris anatomical cross-sectional area (ASCA) was measured using a B-mode ultrasound transducer. Knee extensor strength was assessed using a Cybex Humac Norm at two angular velocities (60 and 120 degrees/sec). Functional muscle quality was calculated for right and left legs as the peak torque (Nm) at each angular velocity divided by the ACSA (Nm/cm). Countermovement jumps were performed in a double and single leg condition, with the task instructions to jump as high as possible. The difference in functional muscle quality between the NWO group and the other two groups was due to strength, not ACSA.