Kickboards can have a negative impact on body position, and while...

How?
It can help them become more skilled at learning to kick to keep the hips up.
And using a kickboard stresses this skill.
When used in appropriate amounts, kickboards can help swimmers improve key kicking skills.
Skills don’t magically show up in races.
Without consistent challenge, there is no improvement.
But here’s the other mistake.
Too much, too fast… also means no improvement.