What can affect bioelectrical impedance?

Accuracy

• Body weight. Bioelectrical impedance analysis may be less accurate in obese people.
• Hydration level. Dehydration may cause fat-free mass (muscle and bone) to be underestimated.
• Recent exercise activity. High-intensity exercise may affect the accuracy of BIA readings.
• Training load.
• Recent food or drink intake.

What affects body fat percentage reading?

The problem is that hydration plays a major role in this reading. A person who is not adequately hydrated may show a higher body fat percentage than is actually accurate, and a person who is overly hydrated might get a number too low.

How does exercise affect bioelectrical impedance?

There is significant difference respectively in weight, BMI, Body fat Percent, impedance (p<0.001) and fat mass, fat free mass, total body water values (p<0.05). Conclusions: Maximal exercise can effect the bioelectrical impedance analysis measurement.

What causes body fat percentage to fluctuate?

Women experience more changes in hydration levels than men because of their menstrual cycle, and this can affect body fat measuring, particularly using the BIA method. Retaining fluid may also cause weight to fluctuate day-to-day during this period causing additional variation in the body fat percentage.

How can I make BIA more accurate?

The use of a single frequency was inaccurate for populations that did not have the standard body type. To improve the accuracy of BIA, researchers created empirical equations using empirical data (gender, age, ethnicity) to predict a user’s body composition.

How do you cheat on BIA?

Eating a meal before a BIA test can cause a decrease in impedance for up to 5 hours after the meal….

1. In the morning after an overnight fast.
2. 5 minutes later after repositioning on scanning bed.
3. 8 hours later after usual daily activities.
4. Next morning before breakfast.
5. Another one 30 minutes after breakfast.

Can dehydration affect body fat percentage?

They tend to under-read body fat percentage. Dehydration is a recognized factor affecting BIA measurements as it causes an increase in the body’s electrical resistance, so has been measured to cause a 5 kg underestimation of fat-free mass i.e. an overestimation of body fat.

Why is my fat percentage higher in the morning?

Any significant changes in body water may affect your body composition readings; for example, the body tends to be dehydrated after a long night sleep so if you take a reading first thing in the morning your weight will be lower and your body fat percentage higher.

Is bioelectrical impedance accurate?

BIA is considered reasonably accurate for measuring groups, of limited accuracy for tracking body composition in an individual over a period of time, but is not considered sufficiently precise for recording of single measurements of individuals.

How do you do bioelectrical impedance analysis?

How Does BIA Work? This non-invasive test simply involves the placement of two electrodes on the person’s right hand and foot. A low level, imperceptible electrical current is sent through the body. The flow of the current is affected by the amount of water in the body.

What are the principles of bioelectrical impedance analysis?

Principles of bioelectrical impedance technique. BIA analysis is based on the principle that electric current flows at different rates through the body depending upon its composition. The body is composed mostly of water with ions, through which an electric current can flow.

What is electelectrical impedance?

Electrical impedance is the alternating current corollary to resistance in direct current circuits and is composed of resistance as well as reactance, which is made up itself of inductance (current induced by magnetic fields) and capacitance (the ability of circuit components to store charge).

What is the history of whole body electrical impedance testing?

In 1983, Nyober validated the use of whole body electrical impedance to assess body composition. By the 1970s the foundations of BIA were established, including those that underpinned the relationships between the impedance and the body water content of the body.

Why do some people have lower impedance than others?

Most of our body water is stored in our muscle. Therefore, if a person is more muscular there is a high chance that the person will also have more body water, which leads to lower impedance.