Changes in Muscle Oxygen Saturation Measured Using Wireless Near-Infrared Spectroscopy in Resistance Training: A Systematic Review

Abstract

Background: This study aimed to report, through a systematic review of the literature, the baseline and final reference values obtained by near-infrared spectroscopy (NIRS) of muscle oxygen saturation (SmO2) during resistance training in healthy adults. Methods: Original research studies were searched from four databases (Scopus, PubMed, WOS, and SportDiscus). Subsequently, three independent reviewers screened the titles and abstracts, followed by full-text reviews to assess the studies’ eligibility. Results: Four studies met the inclusion criteria, data were extracted and methodological quality was assessed using the Downs and Black scale. Muscle oxygen saturation (% SmO2) during reported muscle strength exercises showed a decreasing trend after a muscle strength protocol; that is, before the protocol (range = 68.07–77.9%) and after (range = 9.50–46.09%). Conclusions: The trend of the SmO2 variables is to decrease after a muscle strength protocol. Studies are lacking that allow expanding the use of these devices during this type of training.

Near-Infrared Spectroscopy Used to Assess Physiological Muscle Adaptations in Exercise Clinical Trials: A Systematic Review

“…An increase in the use of NIRS equipment to analyze muscle oxygenation with physical exercise as an intervention was observed. Some characteristics related to its use that favor this increase are its non-invasiveness, portability, real-time measurement, that it does not require trained personnel, its adequate measurement depth, versatility in the measurement of different muscle groups [ 12 ], and, in the most current equipment, the direct determination of molar concentrations of the chromophores present in the tissue (non-arbitrary units), as recently validated [ 61 ]. Table 2 shows that 11 models of NIRS device, belonging to nine manufacturers, were used in 18 clinical trials that evaluated the effects of physical exercise on tissue oxygenation in subjects with pathologies.…”

Haemodynamics and oxygenation in the lower‐limb muscles of young ambulatory adults with cerebral palsy

“…Different exercise types (aerobic exercise 14 as opposed to resistance exercise in our study) may have influenced these results. In addition, methodological differences may partly explain the conflict between the studies, as contrast‐enhanced ultrasound used a sequence of imaging performed lying down that took an average of 168 seconds including recovery time, whereas the NIRS measurements were done within 2 to 4 seconds, thereby better representing the muscle in working condition 29,30 …”

“…High levels of exercise overload induce massive motor‐unit activation—causing mechanical pressure of the muscle fibres to the capillaries, which restricts mBF and oxygen availability—results in a decrease in mBF and mVO 2 with exercise progression 13,27,28 . SmO 2 levels decrease 29 after the initial onset of strength exercise with a greater intensity, resulting in a greater decrease 30 …”

Age-Related Changes in Skeletal Muscle Oxygen Utilization

“…Oxygen levels are measured within skeletal muscle tissue by determining the muscle oxygen saturation (SmO 2 ), depicting the balance between oxygen delivery and consumption [ 9 ]. Oxyhemoglobin (O 2 Hb) and deoxyhemoglobin (HhB) are each assessed to calculate total hemoglobin (O 2 Hb + HhB = ThB) and are typically expressed as a percentage (([O 2 Hb/ThB]) × 100) = %SmO 2 [ 10 , 11 ]. Measurements of SmO 2 are generally obtained via near-infrared resonance spectroscopy (NIRS) [ 10 ], which has been modified from its original use to assess local SmO 2 and blood flow in a muscle of interest at rest, during exercise, and into recovery.…”

“…Oxyhemoglobin (O 2 Hb) and deoxyhemoglobin (HhB) are each assessed to calculate total hemoglobin (O 2 Hb + HhB = ThB) and are typically expressed as a percentage (([O 2 Hb/ThB]) × 100) = %SmO 2 [ 10 , 11 ]. Measurements of SmO 2 are generally obtained via near-infrared resonance spectroscopy (NIRS) [ 10 ], which has been modified from its original use to assess local SmO 2 and blood flow in a muscle of interest at rest, during exercise, and into recovery. Through the use of this device, insight into the overall age-related reduction in oxygen delivery, utilization, and extraction by skeletal muscle can be gained [ 12 , 13 , 14 ].…”