It does not necessarily mean that after improvement now you are faster, stronger, or endure more,....something that you can measure and quantify. A standard quantitative measure does not necessarily apply in evaluating dancing.
But if you are used to see contemporary sports with quantifiable performance, you may have a hard time for this notion to sink in. I am only saying that speed, time, length, height, weight, etc, are not good measurements for dancing.
Improvement in dancing is qualitative. It is about sophistication in the ways you move, communicate with your partner, and work together.
It is certainly true that factors that you can measure (quantitative) can affect your dance greatly, as you are more flexible and can reach further, or you can jump higher or can spin more, so you have more options. Quantitative improvements are, well, quantitative. You can measure the "results". It's much easier to addict to quantitative improvements.
But it is hard to quantify how smooth(awkward) you are, or how good (not-so-good) your dance looks, or how you changed your body usage so you move more elegantly.
Sophistication and elegance sounds like an elusive target. But we should remember that dance improvements are not always coming as improvements in numbers.
