Why football becomes heavier when air is blown into it?

When air is blown into a football, the internal pressure increases, causing the ball to become firmer and more rigid. This added pressure does not significantly change the ball's weight in terms of mass, but it can make it feel heavier to kick or handle due to increased resistance and the firm surface. Additionally, if the ball is filled beyond its recommended pressure, it may also lead to a slight increase in weight due to the added air volume.