Effect of Electrical Muscle Stimulation on Vascular Endothelial Function during Prolonged Sitting

Area of Science:

• Cardiovascular physiology
• Exercise physiology
• Biomedical engineering

Background:

• Prolonged sedentary behaviors (SBs) are linked to increased cardiovascular disease (CVD) risk.
• Interrupting sitting with light exercise can reduce arterial dysfunction.
• Skeletal muscle electrical stimulation (EMS) passively contracts muscles, potentially improving circulation.

Purpose of the Study:

• To investigate the effect of EMS on brachial artery endothelial function during prolonged sitting.
• To determine if EMS can serve as an alternative to active exercise for mitigating sedentary behavior risks.

Main Methods:

• 12 healthy men participated in two conditions: prolonged sitting (CON) and prolonged sitting with lower extremity EMS (EMS).
• Brachial artery flow-mediated dilation (FMD) was measured before and after the intervention.
• Normalized FMD (nFMD) was calculated to assess endothelial function.

Main Results:

• Endothelial function, measured by nFMD, significantly decreased after prolonged sitting in the CON trial.
• No significant change in nFMD was observed during or after prolonged sitting in the EMS trial.
• The EMS trial showed a significant increase in nFMD post-intervention compared to pre-intervention.

Conclusions:

• Passive muscle contraction via EMS enhances brachial artery endothelial function.
• Prolonged use of lower extremity EMS during sedentary periods may reduce the risk of vascular endothelial dysfunction.
• EMS presents a potential strategy to counteract the negative vascular effects of sedentary behavior.