swimswimswim · rubsterbest × jan hercogpremiumsign inv 1.0 / 2026

01 · the session picker

Pick a focus.
Swim it today.

Over 120 sessions out of real training weeks. Set your distance and the session resizes — rounds come off, rounds go back on. No filler.

120+

sessions

35

training weeks

8

load zones

02 · filter

Focus

Target distance

4,000 m
2,000 m6,000 m

03 · your session

StrengthW46/2025 · Drill/Easy

Quiet Water

4,000 m

distance

84 min

approx. time

3,400 m

extended from

warm-up1,250 m · 31%
14 × 200 many stroke (fins optional)R:15sec (suggested)was 2x
29 × 50 mdrill + fins R:15"was 8x
main set2,550 m · 64%
78 × 25 m+ fins + paddles R:45sec" 15m max + 10 easy
15 × 50 mscull R:10"
26 × 150 mfree DPS R:15"was 5x
212 × 100 mfree pull+ paddles R:15sec
cool-down200 m · 5%
1200 mcool-downR:15sec (suggested)
intensity1 · KO · Recovery2 · GA1 ext · Aerobic base, extensive7 · SA · Speed endurance

04 · more sessions

05 · css calculator

Know your
threshold pace.

Two time trials, one number. Your CSS pace is the anchor for every zone — and the pace premium prints next to each rep in a session.

Swim 400 m and 200 m all-out with full rest between them. CSS = (400 − 200) / (time400 − time200) — which is the same as (time400 − time200) / 2 per 100 m. Your honest threshold pace.

example css test session · 1 400 m
  • 400 m warm-up, easy free with 100 m drill mixed in
  • 4 × 50 m build, R:20sec — last one near race speed
  • 100 m loose, then 2 min standing rest
  • 400 m time trial all-out, take the time
  • 200 m very easy, then 5–8 min full rest
  • 200 m time trial all-out, take the time
  • 100 m cool-down

Push both trials evenly, not as a sprint start — and swim the 200 faster per 100 m than the 400, otherwise the maths has nothing to work with. Retest every 6–8 weeks.

save it to your setup → to get a target time on every rep

06 · glossary

Read the
session sheet.

Everything you need to follow a set. If a line still makes no sense, it's a drill. Swim it slowly and it explains itself.

07 · training plans

Sessions are
the easy part.

One good swim doesn't build a season. The plans do — structured, progressive, and used by Ruben himself.

See all training plans →

08 · premium

Your pool,
your pace.

Everything above stays free. Premium runs every session through your pool length (25 or 50 m) and your own CSS pace, so each interval carries a target time you can hold — and rest times built on your speed, not an average.

See premium →free account