Скачать или смотреть Light on the scale. Empty in the legs.

Here's what nobody explains clearly.

When you train properly and eat enough, your body doesn't just get fitter. It gets heavier. Not because you're gaining fat. Because adaptation has mass.
Glycogen and water. Your muscles store carbohydrate as glycogen. It's your primary fuel for efforts. When those stores are full, you're ready to perform. When they're empty, you're not.

Glycogen binds with water. Roughly 3 grams of water for every gram of glycogen. That alone can account for 1.5 to 2 kilos of body mass.
Performance tracks glycogen availability, not the weight on the scale. The water comes with the fuel. You don't get one without the other.

Light on the scale. Completely empty in the legs. Some of the weight you lost might be the fuel you needed to actually perform.