A light electrical current is transmitted through your body for BIA.
AURA Band takes your pulse every 15 minutes when you’re at rest and constantly when you’re working out.
A light electrical current is transmitted through your body for BIA. Fat-free mass contains mostly water, while fat contains very little water. Thus, fat-free mass will have less resistance to an electrical current. By determining the resistance of a current running through your body, the ratio of fat-free and fat mass can be obtained. BIA can also assess the hydration of soft tissue (i.e., body fluid volume) using a specific formula.
However, the convenience of this method comes at the price of accuracy. The main challenge with BIA is that in most BIA devices prediction is based on another prediction, because it is calibrated against other methods like hydrostatic (underwater) weighing or DEXA, which have their own challenges. However, our BIA device and related algorithms were calibrated by assessment against direct tissue weight measurements. In addition, this calibration was improved by BIA prediction of clinical (disease), biochemical (like lipids, proteins, glucose in blood) and physiological (e.g., EMG, ECG, duplex doppler ultrasonography) outcomes in samples of patients with metabolic and cardiovascular diseases and normal subjects.
Moreover, while some BIA devices may not be very accurate for comparing body composition between individuals, they work better when tracking change over time — with longer time intervals producing more accurate data. Constant body and hand positions are very important during BIA for improving accuracy, because they influence the distribution of blood through the body, as well as the fluids in different (e.g., the stomach/intestine, lung) tissues. Proper body contacts with electrodes, excluding extra cross-links like in wet hands or hand-undressed chest contacts to prevent the possibility of the current following the path of least resistance, is another way to increase accuracy.