PhD Scientific Days 2022

Clinical Medicine I. (Poster discussion will take place in the Aula during the Coffee Break)

Extension of Fitness Evaluations with Muscle Oxygen Saturation Measurements Based on Near-Infrared Spectroscopy Analysis in Elite Athletes

Text of the abstract

Introduction: Cardiovascular parameters of sport adaptation have become an area of detailed research in recent years. However, details of local circulatory and metabolic processes ongoing in the working muscles during physical exercise need to be revealed.
Aims: Our aim was to extend cardiopulmonary exercise testing with near-infrared spectroscopy (NIRS) measurements to focus on observing local changes in the contracting muscles.
Method: Mixed muscle oxygen saturation values (SmO2) measured in the vastus lateralis muscle of athletes were analyzed by NIRS during vita maxima treadmill cardiopulmonary exercise testing. Body composition analysis was carried out with bioimpedance method. One-way repeated measures ANOVA, Tukey post-hoc test, Shapiro–Wilk test and Pearson correlation were used for statistical analysis.
Results: The results of 66 elite athletes (male:40; age:17.9±3.6y; training:17.7±6.6h/w) from mixed sports were analyzed. The 10-second averaged values of the measured SmO2 were examined at rest (65.8±11.1%), at the anaerobic threshold (AT, 40.7±22.8%), at maximum load (30.2±20.5%) and after 5 minutes of cool-down (CD, 70.9±12.8%). Significant differences were measured between the four measurement time points in all pairings. A negative correlation was found between the achieved maximal oxygen uptake and the SmO2 measured at the AT and at the maximal load (respectively r=-0.30, p<0.02; r=-0.32, p<0.01). The fat-free mass of the identical limb showed negative correlation with the SmO2 measured at the AT, at the maximal load and at the CD (respectively r=-0.43, p<0.01; r=-0.44, p<0.01; r=-0.35, p<0.01), while positive interactions were observed between the body-fat mass of the same limb and the SmO2 (respectively r=0.51, p<0.01; r=0.55, p<0.01; r=0.41, p<0.01). The SmO2 showed no significant correlations with exercise time, lactate levels, or heart rate measurements.
Conclusion: By our results, SmO2 measurements can be reliably applied during exercise physiological measurements. During exercise, SmO2 values negatively correlated with oxygen uptake. On the identical limb, the higher the muscle mass was, the lower SmO2 could be measured. This easy-to-perform test provides insight into muscle metabolism processes and can help with athlete follow-up.
Funding: K135076; TKP2021-NKTA-46; 2020-4.1.1.-TKP2020; ÚNKP-21-3-I-SE-68; EFOP-3.6.3-VEKOP-16-2017-00009