Near-infrared diffuse correlation spectroscopy tracks changes in oxygen delivery and utilization during exercise with...

Area of Science:

• Physiology
• Biomedical Engineering
• Exercise Science

Background:

• Near-infrared diffuse correlation spectroscopy (NIR-DCS) is an emerging technology for measuring skeletal muscle microvascular oxygen delivery and utilization during exercise.
• The ability of NIR-DCS to accurately track acute changes in these physiological parameters requires further validation.

Purpose of the Study:

• To validate NIR-DCS for assessing acute changes in skeletal muscle oxygen delivery and utilization during exercise.
• To investigate the impact of reduced convective oxygen delivery on muscle oxygen metabolism using NIR-DCS.

Main Methods:

• 14 healthy men performed rhythmic handgrip exercise at 30% maximal voluntary contraction.
• Simultaneous measurements of radial artery blood flow (Duplex Ultrasound) and NIR-DCS variables (BFI, $$, $$) were conducted.
• Brachial artery compression was applied to acutely reduce convective oxygen delivery.

Main Results:

• During exercise, radial artery blood flow and NIR-DCS-derived BFI increased significantly, while $$ decreased.
• Brachial artery compression significantly reduced both blood flow and BFI, and further decreased $$.
• $$ was not significantly reduced due to compensatory increases in oxygen extraction.

Conclusions:

• NIR-DCS effectively tracks changes in skeletal muscle microvascular oxygen delivery and utilization during exercise.
• These findings validate NIR-DCS as a tool for assessing the determinants of skeletal muscle oxygen consumption at the microvascular level.