Virtual reality (VR) technology has emerged as a promising supplementary training tool in football, yet no study has simultaneously examined its effects on technical skills, training load, and mental fatigue within a randomized controlled design. This study evaluated the effects of an 8-week Rezzil Index® VR training program on football-specific technical skills, training load (sRPE), and mental fatigue in licensed male football players. Twenty-four male football players (age: 18.82±0.85 years) were randomly assigned to a VR training group (n=12) or a control group (n=12). The VR group completed two supplementary sessions per week using the Rezzil Index® application (HTC Vive Pro and Oculus Quest 2) in addition to regular team training. Football-specific technical skills, mental fatigue (Modified Color-Word Stroop Test), and training load (session RPE) were assessed pre- and post-intervention. The VR group demonstrated statistically significant improvements in all technical skill measures (p<0.05; d=0.91-1.69, large effects). Rezzil Index® VR training is an effective complementary method for improving football-specific technical skills.

Inclusion Criteria:

• Licensed male football players aged 18 years or older
• Active participation in regular team training
• No history of serious musculoskeletal injury in the past 6 months

Exclusion Criteria:

• History of serious injury or surgical intervention
• Psychiatric or neurological conditions
• Regular use of medication affecting cognitive performance
• Prior experience with VR training systems