Skin Temperature Effects On Mf-bia Accuracy For Skeletal Muscle Mass (smm) Assessments

The accuracy of skeletal muscle mass (SMM) measurements taken via bioelectrical impedance analysis (BIA) is dependent on numerous endogenous factors, including sex and body temperature. Standardization of testing conditions (fasting, ambient temperature, etc.) is vital to ensure precision. To date, skin temperature within both male (M) and female (F) athletes have not been measured to evaluate potential measurement error for SMM when assessed via BIA. PURPOSE: To determine the role of skin temperature on measurement error for SMM in M and F collegiate athletes. METHODS: Skin temperature of collegiate athletes (N = 148) was measured via non-contact infrared thermometer. SMM was measured immediately after via Multi-Frequency Bioelectrical Impedance Analysis (MF-BIA). Lastly, Dual Energy X-Ray Absorptiometry (DXA) was measured for lean body mass (LBM) as a control. Standardization of testing conditions for participants included testing time (6 am - 10 am), fasting (>8 hours), ambient temperature (94 degrees), urination (within 30 minutes), and refraining from exercise (24 hours prior). Independent T-Test analysis was conducted to compare skin temperature between M and F. Additionally, correlation analysis was used to assess the relationship between SMM and LBM. RESULTS: There was a difference in skin temperature between M (N = 75, 97.08° SD = 1.16°) and F (N = 73, 96.94°, SD = 1.15°), p < 0.001. SMM was highly correlated with LBM in both M (R2 = .97; SEE = 3.27) and F (R2 = .91; SEE = 2.91). CONCLUSION: The results show SMM to be highly correlated with reference to LBM within acceptable measurement error. Variation in skin temperature does significantly alter measurement error when stringent standardization protocols are followed.