A Brief Review of the Use of Near Infrared Spectroscopy with Particular Interest in Resistance Exercise

Abstract

There is growing interest in resistance training, but many aspects related to this type of exercise are still not fully understood. Performance varies substantially depending on how resistance training variables are manipulated. Fatigue is a complex phenomenon usually attributed to central (neuronal) and/or peripheral (muscular) origin. Cerebral oxygenation may be associated with the decision to stop exercise, and muscle oxygenation may be related to resistance training responses. Near infrared spectroscopy (NIRS) is a non-invasive optical technique used to monitor cerebral and muscle oxygenation levels. The purpose of this review is to briefly describe the NIRS technique, validation and reliability, and its application in resistance exercise. NIRS-measured oxygenation in cerebral tissue has been validated against magnetic resonance imaging during motor tasks. In muscle tissue, NIRS-measured oxygenation was shown to be highly related to venous oxygen saturation and muscle oxidative rate was closely related to phosphocreatine resynthesis, measured by (31)P-magnetic resonance spectroscopy after exercise. The test-retest reliability of cerebral and muscle NIRS measurements have been established under a variety of experimental conditions, including static and dynamic exercise. Although NIRS has been used extensively to evaluate muscle oxygenation levels during aerobic exercise, only four studies have used this technique to examine these changes during typical resistance training exercises. Muscle oxygenation was influenced by different resistance exercise protocols depending on the load or duration of exercise, the number of sets and the muscle being monitored. NIRS is a promising, non-invasive technique that can be used to evaluate cerebral and muscle oxygenation levels simultaneously during exercise, thereby improving our understanding of the mechanisms influencing performance and fatigue.

Is mean blood saturation a useful marker of tissue oxygenation?

“…The development over the last 30 years of noninvasive optical techniques such as optical reflectance spectroscopy (ORS) (2,18,22,33) and near-infrared spectroscopy (NIRS) (7,23) has significantly advanced our understanding of the hemodynamics of the cutaneous (1,20), muscle (36), cerebral (11,13,29,48), and gastrointestinal (15,38) microcirculation. Furthermore, mean blood saturation (S mb O 2 ) and tissue oxygen index (TOI) derived by ORS and NIRS, respectively, evoke a concept that we can also measure the oxygen delivery to the tissue.…”

Effect of Muscle Strength Training and Muscle Endurance Training on Muscle Deoxygenation Level and Endurance Performance

“…However, it is impossible to measure the path length of the light in biological tissue because it is a scattering media. Therefore, it is difficult to evaluate the absolute value of tissue oxygenation [6][7] . In this study, therefore, muscle deoxygenation level was normalized by the femoral artery occlusion method1 4) before incremental exercise.…”

“…NIRS can monitor the tissue oxygenation of the region of interest, non-invasively and continuously, through different absorptions of near-infrared light in the wavelength region of 700-1000 nm by oxygenated hemoglobin/myoglobin (oxy-Hb/Mb) and deoxygenated hemoglobin/myoglobin (deoxy-Hb/Mb) [6][7] . Since this technique was introduced by Jobsis in 1977 8) , who monitored the changes in the absorption of light in cats and humans, it has been widely applied in various clinical situations and experiments, which have confirmed its validity and reliability 9,10) .…”

Using the Placebo Effect to Isolate Control Mechanisms of Athletic Performance: A Research Protocol

“…It therefore seems to be the ideal tool to research the integration of central and peripheral fatigue processes and determinants of exercise performance. 71 …”