A plateau is not automatically failure
Early in learning or after returning to training, gains can come quickly. Later, improvements often become less obvious. The body and your technique adapt to what you repeat, and the same stimulus eventually creates less change.
A stable period does not necessarily mean the training is bad. It means you need to look more precisely at what is limiting the next step.
First check: are you recovering enough?
If you have added sessions or volume for several weeks and everything is starting to feel heavier, the answer may be a temporary reduction in load. Inadequate recovery can hide the fitness you have already built.
Look at sleep, general fatigue, and whether you can still perform key sets as intended. Adding work to a system that is no longer absorbing the current work does not help.
Information
Second check: does the work still match the goal?
If you want more speed but nearly every session is steady, moderate swimming, more of the same volume may not provide the missing stimulus. The same applies to technique: accumulating metres does not automatically fix a slipping catch or a poorly organized turn.
Change the nature of some of the work before simply increasing the amount.
Change one thing and observe
Add a small speed block with more recovery, revisit a benchmark set, reduce volume for a week, or spend more time on one technical weakness. Avoid changing everything at once.
A clear adjustment lets you see whether it actually addresses the problem.
The plateau may also be a measurement problem
If you only watch your best 100 m, you can miss better consistency, more economical swimming, or weekly volume that now feels easier to absorb. Revisit what “progress” means for the current goal.
Sometimes the next personal best comes after a period when the gains first moved elsewhere: pacing control, technique, strength, or recovery.