According to einstein formula
M= m0/(1- v2/c2 ). As the body speeds up the mass will be greater.
so does that mean mass is not lost instead accumulated when a body speed up?
It shows that if a particle or anything moves with a speed comparable to the speed of the light then its mass will appeared increased because the factor /(1 – v2/c2)1/2 will always be in decimal and something divided by decimal will be more.
I appreciate your curiosity.
Good luck!!!