Let me simplify it.
We know that $F=mg$, where $g$ is the acceleration due to gravity.
Weight has the measurement of force (Newton) so if you are 50Kg, that means your mass times 9.8M/Sec^2 gravitational force is acting on you. This force is resisted by us always, and that is why we could stand on the surface of the earth.
Imagine you are freely falling on the earth. In every second you pick up speed of 9.8 m s^-2.
If we are falling at this speed, we feel weightless, because we dont have resist at all.
But when we are quickly climbing up in the sky, and if the acceleration of climbing is higher than gravitational pull (9.8 m s^-2), then you feel more weight than your normal weight. This is because we are moving against acceleration due to gravity. If it is 5 times, then you will feel 5g.
This can be measured easily. Tie a 5KG stone on a weighing scale and drop it from a height of 1.5m. (Drop it on some shock absorbing material,like bed or something). You see the scale reading when it is free falling - it will be 0.
If you quickly lift this weighing scale upwards and see the reading, it will show an increase in the weight - ie more than 5Kg. The reason is we move the object against gravity and so it increases.