Not only is time affected by relativistic speeds in our space-time continuum, but length is as well. This phenomenon was first explained by FitzGerald and expressed mathematically by Hendrick Lorentz. Because of the two scientists involved, it is often referred to as the FitzGerald-Lorentz contraction. Mathematically, it is a little complex, but it relates the length to the velocity of the object. You do not have to do any problem-solving with the equation, but it is important to note that as the speed approaches the speed of light, the length will approach zero.
\(\large\mathsf{ L = L_0 \sqrt{1 - \frac{v^2}{c^2}} }\)
This contraction is very difficult to measure, because if we are travelling with the object, we too are travelling at the same speed and thus notice no change in the length. Someone who is stationary would say that we did not measure a contraction because the meter stick itself was also travelling at relativistic speeds and thus was contracted itself. The important thing to remember here is that the length doesn't actually contract, but the length appears to contract as it is measured from another observer that is not moving. It is a relative measure. In other words, the contraction is a measurement of the distortion of the object as observed by another space-time.
Question
So, does this length contraction and time dilation apply to mass as well?
In a way, but for mass, the faster an object moves the greater its mass becomes. As a particle approaches the speed of light, the mass becomes infinite. This has been shown experimentally in particle accelerators where the particles are not deflected as much in magnetic fields as they increase their speeds because their mass increases significantly.