Summary of a study looking at represenation and results of athletes born in each month in Olympic weightlifting.
Who
953 Olympic weightlifters (358 females, 595 males) from 5 Olympic Games (2000, 2004, 2008, 2012, 2016).
Design
Comparison of birth-date of Olympic weightlifters who competed in the Olympic Games to the worldwide birth-date distribution for general population.
Outcome measures
- date of birth (relative age effects)
- weight class:
- women:
- lightweight (48, 53, 58 kg)
- middleweight (63, 69 kg)
- heavyweight (75, 75+ kg)
- men:
- lightweight (56, 62, 69 kg)
- middleweight (77, 85, 96 kg)
- heavyweight (105, 105+ kg)
- women:
- success: medalist/non-medalist
- Total, snatch, clean & jerk results
Main results
- The relative age effects (month of birth effects) were present for Olympic weightlifters in general with over-representation in January, and under-representation in June, September and November.
- The relative age effects were present for males in each weight class with over-representation in January, and under-representation of lightweight men in November.
- The relative age effects were present for females in lightweight with over-representation in January, but not in middleweight or heavyweight (this can be biased due to the small sample size).
- No relative age effects were found for snatch, clean & jerk and total lifter kg in both women and men.
- Distribution of male medalists matched global birth distribution (no relative age effects), but for non-medalists there was an over-representation in January, and under-representation in May, October and November.
- For women, there was an over-representation in both medalists and non-medalists in January and under-representation in September.
Take home message
For a clinician & coach
In general, you are more likely to get to the elite (Olympic) level in Olympic weightlifting if you were born in January, and less likely if you were born in June, September and November. Success (medals and results), however, was not affected by the month of birth.
For a parent
In general, you are more likely to get to the elite (Olympic) level in Olympic weightlifting if you were born in January, and less likely if you were born in June, September and November. Success (medals and results), however, was not affected by the month of birth.
For an athlete
In general, you are more likely to get to the elite (Olympic) level in Olympic weightlifting if you were born in January, and less likely if you were born in June, September and November. Success (medals and results), however, was not affected by the month of birth.
Original article
Kollars JM, Taber CB, Beyer KS. Relative Age Effects in Elite Olympic Weightlifters. The Journal of Strength & Conditioning Research. 2021 May 1;35(5):1223-8.