Threshold endurance sets

Setup

1. Group lanes by speed, three to five swimmers a lane, circle swimming with a 5-second gap.
2. Each swimmer takes their average 100 from a recent steady swim (for example a 400 m or 800 m effort) and picks a send-off that leaves roughly 10–20 seconds rest.
3. Warm up for 10–15 minutes before the main set, and keep water bottles at the end of each lane.

How it runs

1. Main set: 8–12 × 100 m freestyle on the send-off at an effort of about 7 out of 10: hard but controlled, able to say a few words at the wall.
2. Aim for the same time on every repeat; swimmers check the clock at each finish.
3. If two repeats in a row come in clearly slower, add 5 seconds to the send-off rather than chasing it.
4. Swim down 200 m easy afterwards.
5. Build up gradually: start with six repeats and add one or two a week while shoulders feel good.

Coaching points

• Even pacing: the first repeat should feel almost too easy.
• Keep the stroke count steady as fatigue builds; a rising count means the stroke is slipping.
• Tight turns keep the work in the swim, not in resting at the walls.
• Rest in the wall corner, off the line of the swimmers coming in.

Common mistakes

• Sprinting the first two repeats and fading badly.
• Stopping in the middle of the lane or hanging on the lane rope.
• Pushing on through a sore shoulder: stop and tell the coach.