001.002 Age Group Overview

This post summarizes the essential statistics of USA-S age group competition.  First we’ll look at the demographics of age group athletes (age and gender). Next we’ll look at the attributes of age group competition, including pool length, seasonality, competition format, strokes, and disqualifications.

Athlete Gender.

Roughly 56% of USA-S age group athletes are female. We’ll learn that female participation peaks at age 11, and that by age 17 there are more male athletes than females.  

Athlete Age.

USA-S age group participation peaks at age 12 and declines sharply thereafter.  The gains in participation from age 7 to 12 are reversed by age 18. We’ll learn that women leave the sport at twice the rate of men.


Freestyle is the most frequently swum stroke, while individual medley is the least.  We’ll learn that relative distribution of strokes doesn’t change much with age, although the preferred distances for each stroke does change.

Pool Length.

USA-S has more than twice as many 25 yard swims (SCY) as 50 meter swims (LCM).  We’ll learn that older athletes are less likely to swim in 25 yard pools.

Two Seasons.

Age group competition is organized into two seasons: short course (from September to March) and long course (from April to July).  Most swims occur in the short course season, in 25 yard pools. The fewest swims occur during the transition months (April, August, and September).

Competition Format.

USA-S recognizes two competition formats: timed finals and preliminaries with finals.  75% of swims are in timed finals, where each participant swims once. We’ll learn that the fraction of timed finals swims declines with age, and that the preliminaries with finals format is unfair.


3% of swims are disqualified for a USA-S rules violation. We’ll learn that the likelihood of being disqualified depends on athlete age, gender, stroke, and pool length.

Looking Forward.

This overview shows that most age group athletes are swimming timed finals in 25 yard pools (SCY).  As they grow older, they are likely to add long course events to their itinerary, and they are more likely to change competition format, from timed finals to preliminaries with finals.