The ‘real’ birthday effect: post-birthday running performance of Football Bundesliga players

ABSTRACT

While the birthday effect has been widely studied in the economics and sport literature, this study introduces the concept of the ‘real’ birthday effect. It holds that birthday celebrations yield fatigue, which negatively affect running performance. The purpose of this study is to examine the effect of players’ birthdays on post-birthday running performance using data from the German Football Bundesliga (2011–2018). The dataset includes 1,040 different field players who played in 2,142 matches (n= 49,233). Running performance was measured by the total distance covered during the game (in m per minute) and the number of intensive runs (>20 and <24 km/h; per minute). On average, players ran 123.68 m and performed 0.70 intensive runs per minute, which are equivalent to 11.1 km and 63 intensive runs during a 90-minute match. The results of fixed effects panel regression analyses, which also control for various player, game, and team characteristics, show that players perform significantly fewer intensive runs on the day following their birthday. This finding supports the concept of the ‘real’ birthday effect. Football coaches should reconsider fielding players on match days succeeding their birthday as these players perform significantly fewer intensive runs.

KEYWORDS:

• Birthday
• Bundesliga
• football
• performance
• soccer

JEL CLASSIFICATION:

• C23
• L83
• Z22

Ethics declaration

Ethical approval was not required because the article is based upon secondary data which are publicly available on internet websites.

Disclosure statement

No potential conflict of interest was reported by the authors.

Data availability

The data are available upon reasonable request from the second author. The data are statistical data on a player-match basis. Data requesters should do the following: Provide the authors of the article a detailed protocol for the proposed study and supply information about the available funding and resources to carry out the study. Invite the original authors to participate in the re-analysis.

Notes

¹ Regarding substitutions, players being substituted in ran significantly more in terms of distance covered and intensive runs. On the contrary, replaced players scored significantly lower on both running parameters, indicating that they might not necessarily have been aware of their replacement ex ante. Anyway, the causality between running performance and substitution is not clear.

Additional information

Funding

This research received no funding.