International Journal of Exercise Science 14(4): 687-695, 2021. Form-fitting spandex swimsuits or single-layer compression shorts are recommended during BOD POD® testing to ensure accurate results. The purpose of this study was to evaluate the effects of various outfit types on body composition measurements using the BOD POD®, and self-reported comfort level wearing each outfit. Twenty-one participants, 8 females and 13 males, (age 31.6 ± 9.8 years) wore a spandex swim cap and three different outfits during BOD POD® testing (manufacturer-recommended form-fitting spandex swimsuit, short sleeve spandex, long sleeve spandex). Measured variables include body mass, body fat percentage, body volume, and self-reported comfort level wearing each outfit. Calculated variables include BMI and body density. Mean body density when wearing the control outfit was 0.004 g/cm3 lower than both short (p \u3c 0.001) and long sleeve (p = 0.001) alternatives. Short and long sleeve outfits resulted in body fat percentage underestimations of 2.0% and 2.1%, respectively (p \u3c 0.001). The short sleeve outfit had the highest mean comfort rating followed by the long sleeve outfit, and the lowest was the control swimsuits. The short sleeve outfit and control outfit had the largest differences in reported comfort levels (p \u3c 0.05). Wearing short and long sleeve spandex outfits instead of recommended form-fitting swimsuits resulted in body density increases and body fat percentage underestimations. Participants should follow manufacturer recommendations by wearing spandex swimsuits. Participants had higher self-reported comfort levels when wearing short or long sleeve outfits
