Discriminating the salivary profile of athletes using ATR-FTIR spectroscopy and chemometrics

Physical activity induces changes in saliva composition which can provide useful qualitative information about an athlete's physical condition. In this study, ATR-FTIR spectroscopy was utilized to collect infrared spectra from saliva samples of 57 male athletes after various physical training conditions. The collected infrared spectra were analyzed using multivariate chemometric techniques (PCA and PLS-DA). PCA proved capable of discriminating between saliva spectra obtained at rest and after physical activity, as well as between the physical condition level of athletes (low vs. high). Furthermore, PLS-DA also showed sufficient discrimination between the two groups of athletes according to their physical condition level and the results of the created prediction model show that this technique is promising for the classification of the samples based on the athletes' level. To our knowledge, this is the first time that saliva spectral signatures via ATR-FTIR spectroscopy and multivariate tools were employed to evaluate the physical condition level of athletes.