RELATIONSHIP BETWEEN SALIVARY BIOMARKERS AND EXTERNAL LOAD IN PROFESSIONAL MALE BASKETBALL PLAYERS DURING A GAME

Abstract

In a sport-specific setting, the external load represents the cumulative amount of stress placed on the athlete during a specific activity, while the internal load describes the athlete’s individual physiological response to that particular activity. The purpose of this study was to determine the relationship between external load measured with a tri-axial accelerometer and salivary testosterone (T), cortisol (C), and testosterone-to-cortisol ratio (T/C) as measures of internal load during a 5-on-5 basketball game. Six professional male basketball players volunteered to participate in the investigation (age=28.3±1.9 years; height=193.3±10.6 cm; body mass=90.7±10.7 kg). Upon completing a standardized warm-up protocol, athletes played a simulated basketball game composed of four 10-minute quarters with the Elam Ending. Each athlete wore a tri-axial inertial measurement unit (StriveTech, Bothell, WA, USA) embedded within tightly fitted compression shorts throughout the competitive period. The salivary samples were collected immediately upon arrival at the gym and immediately after each quarter. To determine the relationship between the external load and T, C, and T/C, separate restricted maximum likelihood linear mixed-effects models were fitted (p<0.05). External load demonstrated a strong positive relationship with C (p<0.001, F=49.03, R2=0.59, R2CI=0.36-0.78) and a strong negative relationship with T/C (p<0.001, F=56.53, R2=0.61, R2CI=0.39-0.79). Overall, these findings simply that C may be a valuable biomarker for assessing the summative psychophysiological stress experienced during competitive 5-on-5 basketball play as a gradual rise in C was observed along with accumulating external loads.