How Katie Ledecky Trains (the Most Aerobic Athlete in the Pool)

Katie Ledecky races a pace, not an opponent, on huge aerobic volume held to precise splits. How she trains, and why swimmers set zones by stopwatch.

Sven Ahrens2026년 7월 30일마지막 업데이트 2026년 9월 6일

swimmingcssdistanceaerobic basepace

Katie Ledecky holds the world records in the 800m and 1500m freestyle, has nine Olympic gold medals, and in 2025 became the first swimmer of any gender to win seven world titles in a single event. Her sport is holding a precise pace for longer than anyone else can, and she trains it the way an amateur should: against the clock, not a heart-rate strap.

The most aerobic athlete in the pool

Distance freestyle is one of the most aerobic events in sport. Under coach Anthony Nesty at the University of Florida, where she moved in 2021, Ledecky reportedly covers around 45 miles a week in the pool on top of dryland and weight-room work, training in the distance group alongside the university's men.

Her coaching lineage runs from Yuri Suguiyama to Bruce Gemmell to Greg Meehan and now Nesty. The throughline is high, precise volume. On her 2024 to 2025 block: "By Christmas training, I was doing things I've never done before from a yardage perspective, from intensity, from times I'm hitting in practice while doing that kind of yardage."

She races a pace, not an opponent

Ledecky leads from the front and wins by open water, so she is rarely racing the swimmer next to her. She races a target split she knows she can hold while everyone else fades. That is built with descending and hold-pace sets: not "swim hard" but "hold this exact time per hundred, then this slightly faster one." One documented set from her development was eleven 400s descending from around 4:07 to 3:49, each swum to a target.

It is the same discipline as Kipchoge's controlled easy running and Ingebrigtsen's lactate-capped thresholds: pick a number you can repeat and hold it.

Why swimmers use a stopwatch, not a heart strap

Heart rate barely works in the water. Being horizontal and immersed blunts the response, and reading a monitor mid-stroke is impractical. Swimmers use pace per hundred instead. Where Léon Marchand's medley training leans on short rest and race-pace intensity, Ledecky's leans on holding a pace over long sets. Both are organised around the same external number.

The amateur version is Critical Swim Speed, estimated from two time trials:

임계 수영 속도

1:35/100m

CSS 속도

1.05m/s

존	범위	무엇을 단련하는가
Z1	회복 1:43–1:47 /100m	쉬운 기술 및 회복 수영. RPE 2–3, 매끄러움.
Z2	지구력 1:37–1:43 /100m	유산소 기초; 길고 꾸준한 세트. RPE 4–5, 편안함.
Z3	역치 (CSS) 1:33–1:37 /100m	임계 수영 속도, 즉 지속 가능한 역치 페이스. RPE 6–7, 편안하게 힘듦.
Z4	VO₂max 1:29–1:33 /100m	최대 유산소; 레이스 페이스 인터벌. RPE 8–9, 힘듦.
Z5	스프린트 1:21–1:29 /100m	스피드와 무산소 파워; 짧고 빠른 반복. RPE 9–10, 매우 빠름.

회복

1:43–1:47 /100m

지구력

1:37–1:43 /100m

역치 (CSS)

1:33–1:37 /100m

VO₂max

1:29–1:33 /100m

스프린트

1:21–1:29 /100m

Z1 · 회복. 쉬운 기술 및 회복 수영. RPE 2–3, 매끄러움.

Z2 · 지구력. 유산소 기초; 길고 꾸준한 세트. RPE 4–5, 편안함.

Z3 · 역치 (CSS). 임계 수영 속도, 즉 지속 가능한 역치 페이스. RPE 6–7, 편안하게 힘듦.

Z4 · VO₂max. 최대 유산소; 레이스 페이스 인터벌. RPE 8–9, 힘듦.

Z5 · 스프린트. 스피드와 무산소 파워; 짧고 빠른 반복. RPE 9–10, 매우 빠름.

임계 수영 속도는 당신의 역치 페이스로, 여기서는 100 m당 약 1:35입니다. 200 m와 400 m 노력의 기울기에서 나오므로, 둘 다 진짜 최대 강도이고 페이스가 잘 조절되어야 합니다.
CSS는 같은 세션에서 400 m와 200 m 타임 트라이얼로 수영하되, 사이에 완전히 휴식을 취하세요. 200 m가 400 m 페이스보다 그다지 빠르지 않다면 400 m를 충분히 강하게 하지 않은 것일 가능성이 높습니다.
물속에서는 심박수가 신뢰할 수 없으므로, CSS 페이스가 수영 훈련에서 가장 실용적인 기준입니다.

당신의 개인 맞춤 결과가 담긴 PDF와, 언제든 다시 열 수 있는 QR 코드.

Swim a 400 and a 200 as hard as you can hold, enter the times, and you get your CSS: the pace that approximates your swimming threshold. Easy swims sit a few seconds per hundred slower, threshold sets at it, fast work above it. Most amateur swimmers grind every length at a vague effort with lots of wall-hanging, which builds neither base nor speed. Anchoring to CSS fixes both.

2024 to 2026

Ledecky won the 800m and 1500m freestyle at the 2024 Paris Olympics, then at the 2025 World Championships in Singapore became the first swimmer to win seven world titles in the same individual event, the 800m freestyle. As of 2026 she is still based at Florida under Nesty and still extending records she set as a teenager.

What you can steal from it

Build the aerobic base. Distance swimming is built with patient volume at controlled efforts.
Set your swim zones from a stopwatch. Heart rate does not work in water. Critical Swim Speed is the swimmer's threshold.
Hold a pace, don't "swim hard." Give every set a number and hold it.
Descend on purpose. Sets that step down through known paces teach control.
Play the long game. Her dominance rests on more than a decade of aerobic work.

More in this series: Léon Marchand, Kristian Blummenfelt, Eliud Kipchoge and the fast age-grouper on eight hours a week.

Sources

Cover photo by Voltmetro, CC BY-SA 4.0, via Wikimedia Commons.