Phase angle, muscle tissue, and resistance training

Abstract

The biophysical response of the human body to electric current is widely appreciated as a barometer of fluid distribution and cell function. From distinct raw bioelectrical impedance (BIA) variables assessed in the field of body composition, phase angle (PhA) has been repeatedly indicated as a functional marker of the cell’s health and mass. Although resistance training (RT) programs have demonstrated to be effective to improve PhA, with varying degrees of change depending on other raw BIA variables, there is still limited research explaining the biological mechanisms behind these changes. Here, we aim to provide the rationale for the responsiveness of PhA determinants to RT, as well as to summarize all available evidence addressing the effect of varied RT programs on PhA of different age groups. Available data led us to conclude that RT modulates the cell volume by increasing the levels of intracellular glycogen and water, thus triggering structural and functional changes in different cell organelles. These alterations lead, respectively, to shifts in the resistive path of the electric current (resistance, R) and capacitive properties of the human body (reactance, Xc), which ultimately impact PhA, considering that it is the angular transformation of the ratio between Xc and R. Evidence drawn from experimental research suggests that RT is highly effective for enhancing PhA, especially when adopting high-intensity, volume, and duration RT programs combining other types of exercise. Still, additional research exploring the effects of RT on whole-body and regional BIA variables of alternative population groups is recommended for further knowledge development.

EXERT-BC: Prospective study of an exercise regimen after treatment for breast cancer

“…[37] Significant improvement was seen in phase angle in just three months of resistance training, raising the question as to whether this is one mechanism exercise may improve cancerspecific outcomes. [38] The age and functional status of the women on this study varied significantly, with a minority already engaged in a resistance training or exercise regimen prior to enrollment on the protocol. Additionally, the majority had chronic musculoskeletal, joint, or orthopedic issues, yet were capable of engaging in an intense exercise regimen utilizing compound movements and heavy weights.…”

Utilization of bioelectrical impedance vector analysis (BIVA) in children and adolescents without diagnosed diseases: a systematic review

“…The studies agreed that the vectorial approach appears to be more efficient as it combines two types of influential variables (raw parameters), the PhA and vector lengths (Carrasco-Marginet et al 2017, Marini et al 2020). However, to provide more valid comparisons among different BIVA findings, especially with reference values, researchers are recommended to always use specific electrodes for each equipment, thus avoiding any interference in the measurement (Sardinha andRosa 2023, Ward andBrantlov 2023).…”

Bioelectrical impedance phase angle is associated with physical performance before but not after simulated multi‐stressor military operations

“…PhA in the human body typically ranges from 1° to 12° (Sardinha & Rosa, 2023 ), and higher values within this range are positively associated with muscle strength and physical function (Cioffi et al, 2020 ; Custodio Martins et al, 2022 ; Fukuoka et al, 2022 ; Giorgi et al, 2018 ; Langer et al, 2022 ; Micheli et al, 2014 ; Norman et al, 2011 ; Piccoli et al, 2007 ; Rodriguez‐Rodriguez et al, 2016 ; Sato et al, 2020 ). Increases in PhA have been reported following resistance training programs and concurrent exercise training (Campa, Colognesi, et al, 2022 ; Sardinha & Rosa, 2023 ).…”

“…PhA in the human body typically ranges from 1° to 12° (Sardinha & Rosa, 2023 ), and higher values within this range are positively associated with muscle strength and physical function (Cioffi et al, 2020 ; Custodio Martins et al, 2022 ; Fukuoka et al, 2022 ; Giorgi et al, 2018 ; Langer et al, 2022 ; Micheli et al, 2014 ; Norman et al, 2011 ; Piccoli et al, 2007 ; Rodriguez‐Rodriguez et al, 2016 ; Sato et al, 2020 ). Increases in PhA have been reported following resistance training programs and concurrent exercise training (Campa, Colognesi, et al, 2022 ; Sardinha & Rosa, 2023 ). Alternatively, low PhA has been reported in individuals presentingmalnutrition, alcoholism, cancer/cachexia, HIV, sarcopenia, and in older adults (Cardinal et al, 2010 ; Fukuoka et al, 2022 ; Genton et al, 2017 , 2018 ; Gupta et al, 2008 ; Lukaski et al, 2017 ; Nescolarde et al, 2013 ; Tanaka et al, 2019 ; Toso et al, 2000 ).…”