Introduction: Handball is a team sport that consists of sudden movements and changes of direction. Contact is one of the main components of the game and often leads to serious injuries. Due to the fast game, high jumps and landings, male and female players often get injured and thus shorten their careers. Other factors that can affect performance and injuries are sleep quality and overtraining. Professional athletes sleep less due to the accelerated pace of life and the amount of training aimed at better results. Aim of the research: This research aims to determine whether there is a relationship between injuries and the amount of sleep players have, as well as a relationship with the number of training sessions per week. Respondents and methods: A total of 28 respondents participated in the research, 12 male handball players and 16 female handball players. Out of 28 respondents, only three were never injured during their handball career. The research was conducted at the beginning of April 2023 in the men's and women's handball club Zamet. For the purposes of the work, a non-standard questionnaire was used. The data was collected personally in the Zamet hall. The respondents filled out the questionnaire after the training. Each respondent filled out the questionnaire individually and independently. The duration of the research is on average 4-5 minutes. The correlation coefficient was used for all mentioned hypotheses in the research. Statistical significance for all hypotheses is shown as P < 0.05. All obtained data will be processed in the program Statistica 14.0.0.15 (TIBCO Software Inc) and are presented graphically and in tables. Results: Using the correlation coefficient, it was determined that there is no statistically significant association of injuries with the amount of training more than three times a week. Likewise, we proved by correlation that there is no connection between the number of training sessions and injuries among male and female handball players of the Zamet handball club. The hypotheses were rejected and we came to the conclusion that there is no statistically significant relationship between the amount of sleep and the number of training sessions with injuries in the men's and women's handball club Zamet. Conclusion: In order to understand the importance of the quality of sleep and rest, further research is needed on this topic. Overtraining can lead to fatigue and consequently injury. Therefore, it is necessary to include a larger number of respondents in the research.