Mindset

Comparing swimmers of the same age: what the gap shows

Comparing swimmers of the same age mostly shows differences in growth and timing. Use your swimmer’s clock and next step. Treat the other swimmer as a training partner.

September 21, 2026 · 3 min read

Idea in Brief

  • Same escalão does not mean same body. Maturity can differ by years.
  • Birth month shapes notice more than speed. Portuguese data found uneven selection, with little effect on speed.
  • Use the clock and what comes next. The other swimmer is a training partner.

At the wall, your daughter watches the other swimmer’s time appear. The four-second gap is the fact you both carry home. Yet the lane next door is the least useful measure in the building. Swimmers in the same escalão, or age category, can have bodies at different points.

A British Journal of Sports Medicine review by Malina and colleagues shows how wide that gap can be. In longitudinal studies of European youth, age at peak height velocity, the fastest year of growing, ranged from about 9.0 to 15.0 years in girls and 11.5 to 17.3 in boys. In swimming, boys aged 10 to 12 covered the whole maturity range. Girls under 14 did too, though more were average or early. By 14 to 15, most were average or advanced; most aged 16 to 17 were skeletally mature. Infantis A and Juvenis B still carry that spread, so maturity is one factor rather than a full explanation.

Costa and colleagues studied the best 50 Portuguese swimmers aged 12 to 18 across 7,813 event participations. Birth dates were uneven across the year, with more swimmers born in the first half. Within that group, birth quarter mostly made no difference to speed. Being born early in the year may help a swimmer get noticed more than it helps them swim. The Malina review also found that selected groups narrow from about 11–12 to 15–16 as fewer late maturers remain. These patterns do not tell you which swimmer will lead later.

Comparison changes what a swimmer chases. At home, it can sound like a parent saying, “She’s dropped more than you this year.” Focus shifts from her work to someone else’s body and timing. What gets celebrated is what they learn to seek. Place measures the field; the personal best measures the swimmer. At dinner, use the clock and the next thing: “What did your time show, and what’s next?” This notices the other swimmer without making her the standard.

Coaches do compare swimmers for lanes, groups and relay order. That is their work, and group placement stays with them. Talking to the coach can help keep that line clear. For your swimmer, the kid in the next lane is a training partner first. Someone to chase in the last set can offer something a stopwatch cannot. When comparison appears, return to the clock. Then let the other swimmer go back to being a training partner.

Share it with your swimmer

Use words that fit their age:

  • Under 12 (you’re driving). “She’s your training partner. What did your clock show?” to give them one clear measure.
  • 12–15 (sharing the wheel). “Bodies grow on different clocks. What’s next for you?” to send comparison somewhere useful.
  • 16+ (they’re driving). “I saw the gap too. How are you reading it?” to hear their view first.

Stay aligned with your coach

The coach compares swimmers for lanes, groups and relay order. The parent keeps home talk on their swimmer’s clock and next step. Ask, “What should we watch in her own progress?” and leave placement with the coach.

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