001.003 Age Group Demographics

This post summarizes the gender and age distribution of USA-S age group athletes.  We’ll learn that 56% of age group athletes are female. We’ll also learn that age group participation peaks at age 12, and declines rapidly thereafter, more so for women than men.


Our analysis uses both historical and current data.  For historical data, we’ll use our database of 23 million USA-S age group swims collected across 14 years from 18 LSCs and 1 Zone.  For current data, we’ll use current team rosters from all 59 LSCs published on swimmingrank.com.  By combining a longitudinal sample with a latitudinal snapshot, we hope to provide a more accurate picture of USA-S age group participation.

Gender.

According to our historical data, 56.3% of USA-S age group athletes are female.


According to the club rosters on swimmingrank.com as of 2019-05-02, 56.1% are female.


Gender Fraction by Age.

According to our historical data, the fraction of female athletes peaks at 59% at age 11 and declines to 44% at age 18.

According to current swimmingrank.com team rosters, the fraction of female athletes peaks at 58% at age 11 and declines to 47% at age 18.

Age.

According to our historical data, USA-S age group participation peaks at age 12 and declines thereafter.  The gains in participation from age 7 to 12 are reversed by age 18.

Breaking out athlete participation by age and gender shows that participation declines more for women than men after age 12.

Current team rosters on swimmingrank.com confirm the age-related decline in USA-S participation.

The age-related decline in participation contributes to an age-related decline in the number of swims. The decline in swims is more precipitous than the decline in athletes, which suggests that older athletes compete less frequently.

Conclusions.

Our preliminary review of the data identifies a sharp decline in the number of swims by older USA-S age group athletes. In a subsequent post, we will find that the decline is caused by fewer athletes attending fewer meets and swimming fewer events (link). We’ll also confirm that girls leave the sport at a significantly higher rate than boys.