We examined the influence of graded cold-water immersion (CWI) on global and regional quadriceps muscle perfusion using positron emission tomography (PET) and [¹⁵O]H₂O. In thirty healthy males (33±8 yrs; 81±10 kg; 184±5 cm; percentage body fat: 13±5%; V̇O_2peak: 47±8 mL·kg^-1·min^-1) quadriceps perfusion, thigh and calf cutaneous vascular conductance (CVC), intestinal, muscle and local skin temperatures, thermal comfort, mean arterial pressure and heart rate were assessed prior to and following 10-min of CWI at 8°C, 15°C or 22°C. Global quadriceps perfusion did not change beyond a clinically relevant threshold (0.75 mL∙100g∙min^-1) in any condition, and was similar between conditions [range of the differences (95% confidence interval [CI]); 0.1 mL∙100g∙min^-1 (-0.9 to 1.2 mL∙100g∙min^-1) to 0.9 mL∙100g∙min^-1 (-0.2 to 1.9 mL∙100g∙min^-1)]. Muscle perfusion was greater in vastus intermedius (VI) compared with vastus lateralis (VL) (2.2 mL∙100g∙min^-1; 95%CI 1.5 to 3.0 mL∙100g∙min^-1) and rectus femoris (RF) (2.2 mL∙100g∙min^-1; 1.4 to 2.9 mL∙100g∙min^-1). A clinically relevant increase in VI muscle perfusion after immersion at 8°C and a decrease in RF muscle perfusion at 15°C were observed. A clinically relevant increase in perfusion was observed in the VI in 8°C compared with 22°C water (2.3 mL∙100g∙min^-1; 1.1 to 3.5 mL∙100g∙min^-1). There were no clinically relevant between-condition differences in thigh CVC. Our findings suggest that CWI (8-22°C) does not reduce global quadriceps muscle perfusion to a clinically relevant extent, however, colder-water (8°C) increases deep muscle perfusion and reduces (15°C) superficial muscle (RF) perfusion in the quadriceps muscle.

This study investigated the magnitude and direction of inter-limb asymmetry in 21 professional female sepak takraw players across several task-specific tests. Five inter-limb asymmetry assessments were employed: unilateral countermovement jump (Uni-CMJ), bilateral countermovement jump (Bi-CMJ), single-leg hop (SLH), triple hop test (THOP), and isokinetic concentric peak torque of the knee flexors and extensors at 60 deg/s⁻¹, 120 deg/s⁻¹, and 180 deg/s⁻¹ angular velocities. A “true” inter-limb asymmetry was only observed for Uni-CMJ jump height (16.62%) and THOP distance (6.09%). Kappa coefficients demonstrated fair agreement in the direction of asymmetry between the Uni-CMJ and Bi-CMJ tests for jump height (Kappa = 26.67), but only slight agreement for peak force (Kappa = 0.11), propulsive impulse (Kappa = −0.12), and eccentric impulse (Kappa = −0.14). Fair agreement was observed between the SLH and THOP (Kappa = 0.32). Slight to moderate agreement was found for concentric peak torque across angular velocities for the knee extensors (Kappa = 0.08 to 0.48), while fair to nearly perfect agreement was noted for the knee flexors (Kappa = 0.31 to 1). The Uni-CMJ and THOP are most sensitive to detect between-limb asymmetries in female sepak takraw players. Given the inconsistencies in asymmetry direction across tests, monitoring asymmetry direction is important for strength and conditioning.

This study investigated the magnitude and direction of inter-limb asymmetry in 21 professional female sepak takraw players across several task-specific tests. Five inter-limb asymmetry assessments were employed: unilateral countermovement jump (Uni-CMJ), bilateral countermovement jump (Bi-CMJ), single leg hop (SLH), triple hop test (THOP), and isokinetic concentric peak torque of the knee flexors and extensors at 60 deg/sec-1, 120 deg/sec-1 and 180 deg/sec-1 angular velocities. A “true” inter-limb asymmetry was only observed for Uni-CMJ jump height (16.62%) and THOP distance (6.09%). Kappa coefficients demonstrated fair agreement in the direction of asymmetry between the Uni-CMJ and Bi-CMJ tests for jump height (Kappa = 26.67), but only slight agreement for peak force (Kappa = 0.11), propulsive impulse (Kappa = -0.12) and eccentric impulse (Kappa = -0.14), respectively. Fair agreement was observed between the SLH and THOP (Kappa = 0.32). Slight to moderate agreement was found for concentric peak torque across angular velocities for the knee extensors (Kappa = 0.08 to 0.48) while fair to nearly perfect agreement was noted for the knee flexors (Kappa = 0.31 to 1). The Uni-CMJ and THOP are most sensitive to detect between-limb asymmetries in female sepak takraw players. However, given the inconsistency in asymmetry direction across tests, monitoring asymmetry direction is crucial for conditioning.