3-2-1 Countdown Swim: Descending Distance Speed Set

Session Overview

The 3-2-1 countdown set pairs descending distances with increasing intensity — you swim 300m at moderate effort, then 200m at CSS threshold, then 100m all-out sprint, before a short rest and a second round. It’s a 45-minute pool session that sharpens finishing speed while building aerobic base, perfect for intermediate swimmers preparing for their race season.

What You’ll Need

  • 25m or 50m pool with pace clock or waterproof watch
  • Kickboard for warm-up kick work (optional)
  • Knowledge of your CSS pace for the 200m block

Warm-Up (10 minutes)

400m easy continuous freestyle at RPE 3/10, alternating between full stroke and 4 x 25m catch-up drill every 100m. Your stroke should feel loose and your breathing settled before you begin the main set.

Main Set

Complete two full rounds of the 3-2-1 countdown. The key is to lift effort through each descending block — the 300m should feel comfortable, the 200m hard, and the 100m an all-out sprint. Start conservatively in Round 1 to ensure you can repeat in Round 2.

  • 300m at 70% effort (CSS minus 5 seconds per 100m), 30 seconds rest
  • 200m at CSS pace (RPE 7–8/10), 30 seconds rest
  • 100m sprint (RPE 9/10 — max sustainable sprint), 90 seconds rest
  • Repeat once for a second round

Cool-Down (5 minutes)

200m easy backstroke or choice drill to settle HR and loosen the shoulders. Focus on slow, full breathing and a long, relaxed stroke.

Coaching Notes

  • Start the 300m slower than you think necessary — you still have two harder blocks ahead
  • The 100m sprint should feel genuinely hard; focus on maintaining stroke form as fatigue sets in
  • If 30 seconds rest is too short after the 300m in Round 1, take 45 seconds — quality beats pace
  • Target RPE: 300m = 6/10, 200m = 7–8/10, 100m = 9/10

Training at your own risk. The information provided is for general guidance only and is not a substitute for professional medical advice. Please consult a doctor before starting any new exercise programme, especially if you have any pre-existing health conditions.