The Development of the Sports Careers of the Best Decathletes in the World and in Poland in the Years 1985–2015

Introduction. The main goal of the study was to examine the changes in the scores achieved by a group of the best decathletes in Poland and in the world over the duration of their entire sports careers. Material and methods. The study examined the careers of 25 top decathletes in Poland and 25 top decathletes in the world who achieved their best scores in the decathlon in the years 1985-2015. Changes in their performance were analysed using three research protocols, which explored the relationships between the decathletes’ performance and their age, the number of years of training completed, and the number of years elapsed before and after the decathletes achieved their personal best scores. In order to analyse the data, some basic descriptive statistics, performed segmented regression, and computed fixed-base and chain indices were calculated. Conclusions. The findings of the current study indicate that decathletes achieve the best outcomes between the ages of 25 and 30. Furthermore, it was found that the time when the personal best scores were attained was preceded by the greatest increases in the level of performance and followed by the largest decreases in performance. Determining the way performance outcomes change in particular years of the career of a decathlete can help manage their training in different phases of their career more effectively.