The mistake most swimmers make
The first 500-yard swim is not built by forcing one long swim every time you go to the pool. It is built by making short repeats calm enough that your breathing and form survive the whole session.
A better progression
- Start with 25s or 50s that feel controlled.
- Keep the rest consistent so you can compare sessions week to week.
- Add distance only when your final repeats look close to your first repeats.
Simple pool set
Try 8x50 freestyle with 20 to 30 seconds rest. If the final two 50s stay calm, next time try 4x100. If they fall apart, repeat the same set and make the first four easier.