The relationship of muscle oxygen saturation analyzer with other monitoring and quantification tools in a maximal incremental treadmill test

Abstract

Introduction: The study aims to explore whether NIRS derived data can be used to identify the second ventilatory threshold (VT2) during a maximal incremental treadmill test in non-professional runners and to determine if there is a correlation between SmO2 and other valid and reliable exercise performance assessment measures or parameters for maximal incremental test, such as lactate concentration (LT), RPE, HR, and running power (W).Methods: 24 participants were recruited for the study (5 women and 19 men). The devices used consisted of the following: i) a muscle oxygen saturation analyzer placed on the vastus lateralis of the right leg, ii) the Stryd power meter for running, iii) the Polar H7 heart rate band; and iv) the lactate analyzer. In addition, a subjective perceived exertion scale (RPE 1-10) was used. All of the previously mentioned devices were used in a maximal incremental treadmill test, which began at a speed of 8 km/h with a 1% slope and a speed increase of 1.2 km/h every 3 min. This was followed by a 30-s break to collect the lactate data between each 3-min stage. Spearman correlation was carried out and the level of significance was set at p < 0.05.Results: The VT2 was observed at 87,41 ± 6,47% of the maximal aerobic speed (MAS) of each participant. No relationship between lactate data and SmO2 values (p = 0.076; r = −0.156) at the VT2 were found. No significant correlations were found between the SmO2 variables and the other variables (p > 0.05), but a high level of significance and strong correlations were found between all the following variables: power data (W), heart rate (HR), lactate concentration (LT) and RPE (p < 0.05; r > 0.5).Discussion: SmO2 data alone were not enough to determine the VT2, and there were no significant correlations between SmO2 and the other studied variables during the maximal incremental treadmill test. Only 8 subjects had a breakpoint at the VT2 determined by lactate data.Conclusion: The NIRS tool, Humon Hex, does not seem to be useful in determining VT2 and it does not correlate with the other variables in a maximal incremental treadmill test.

Reliability of threshold determination using portable muscle oxygenation monitors during exercise testing: a systematic review and meta-analysis

“…Furthermore, no matter in which lateral vastus (right or left) the NIRS device was placed and the modality (cycling or running) it detected the MOT correctly McMorries et al 49 N = 7 (M); 14 (F) Trained Triathletes GXT ↑ 12–18 s per km every 180 s * Treadmill LT 2 BSX Insight GC MOT 2 showed similar values to LT 2 , when the thresholds were compareted using the heart rate Raleigh et al 41 N = 31 (M) Highly trained cyclist/triathletes GXT 15-min W-UP (120 W) 3-min (100 W) ↑ 25 W every 180 s * Cycle Ergometer LT 2 , VT 2 Moxy VL MOT 2 , LT 2 and VT 2 were not different, but a poor correlation was obtained between them A good correlation was identified between VT 1 and LT 1 Rodrigo-Carranza et al 25 N = 5 (M); 5 (F) Highly trained runners GXT 5-min W-Up (9 km·h −1 ) ↑ 1 km·h −1 every 60 s * Treadmill VT 2 Humon Hex VL VT 2 and MOT 2 were positively correlated during running. Thus, the device presented a good predictor of the second threshold Osmani et al 40 N = 16 (M); 5 (F) Recreationally GXT 3-min work + 30 s rest 8.0 km h −1 W-UP ↑ 1.2 km h −1 every 180 s * Treadmill VT 2 Humon Hex VL SmO 2 data alone were not enough to determine the VT 2 Also, SmO 2 values of this device (Humon) do not correlate with other variables (blood lactate, RPE, HR and running power) Salas-Montoro et al ...…”

“…4 of the article ICC: 0.97 Cayot et al 46 Dmax and modified Dmax LT 2 was determined using a Dmax and mDmax Authors did not provide the dataset after requestion – Driller et al 47 Wearable lactate threshold sensor (WLT) LT 2 was determined using: TradLT, Dmax, mDmax and OBLA Calculated from data obtained from the Fig. 2 of the article TradLT: 0.96 Dmax: 0.88 mDmax: 0.97 OBLA: 0.96 ICC mean: 0.94 Farzam et al 48 Application Humon Beta LT 2 was determined using the value of 4 mmol·L −1 lactate Authors did not provide the dataset after requestion – Feldmann et al 16 Segmented linear regression model VT 1 and VT 2 were detected with a segmented regression analysis Provided by the authors LT 1 running: 0.49 LT 1 cycling: 0.65 ICC mean : 0.57 LT 2 running: 0.92 LT 2 cycling: 0.92 ICC mean : 0.92 McMorries et al 49 Wearable lactate threshold sensor (WLT) LT 2 was determined using the value of 4 mmol·L −1 lactate and an increase greater than 1 mmol·L −1 Calculated from data obtained from the Figure 6 of the article ICC: 0.29 Osmani et al 40 Visual identification VT 2 was determined observing an inflection point Calculated from data obtained from the Tables 1 and 2 of the article …”

“…However, the ICC value of two studies were not obtained 46 , 48 . The remaining studies also compared gas exchange with muscle oxygenation in the second threshold in cycling 16 , 39 , 42 , 43 and running 16 , 40 . The results of the different studies suggest that the relationship between both methods in threshold determination is affected by the region assessed by the NIRS device, as good values (ICC = 0.92–0.97) were observed on assessing the intercostalis during cycling 39 .…”

Assessment of Intercostal Muscle Near-Infrared Spectroscopy for Estimating Respiratory Compensation Point in Trained Endurance Athletes

“…The values for the SmO 2 BP and RCP cutoff points were identified independently for each individual, and the data were aligned in time with the start of exercise at time "zero" [15]. Two experienced researchers verified the values of both measurement methods, resolving conflicts by consensus [7,15].…”

“…A promising method to obtain this additional information is near-infrared spectroscopy (NIRS), a tool that allows measurement of muscle oxygen saturation (SmO 2 ) in targeted muscles [6][7][8][9]. These devices allow for the capture of optical changes at varying wavelengths to quantify SmO 2 levels in a simple and non-invasive way.…”