Introduction:
Badminton is one of the most popular sports which requires agility and strength. It is also a sport that needs a good amount of physical, physiological, technical and tactical assessment and training.

Aim of the study:
The purpose of this study was to investigate effects of training based on an undulating periodization routine supported by scientific assessments of physical and physiological variables of badminton players

Material and methods:
Twenty players registered themselves to take part in the study, however, a group of 10 male badminton players was eligible to participate after meeting inclusion criteria. Flexibility, handgrip strength, dynamic balance, agility, and aerobic capacity tests were performed before a commencement of a training routine, which consisted of endurance activities, mobility exercises, and strength sessions based on a previous scientific assessment. The same test parameters were also assessed after the training period. The athletes continued their badminton training for 12 weeks, which was also included in the customized training routine. A statistical analysis was performed to compare obtained data before and after the training program. Normality of the obtained data was also assessed.

Results:
Significant improvements in handgrip strength and agility (p < 0.05) were noted. In addition, positive trends were observed in flexibility, dynamic balance and aerobic capacity of the athletes.

Conclusions:
The 12-week customized training routine consisting of undulating periodization had positive effects on strength, mobility, agility and other physiological variables of the badminton players. However, better results may be achieved by continuing this training routine in the future.