It is general that all people always think that doing cardio before weight training is normal and that it is one of the best ways to warm up the muscle, but it has created a lot of concerns about whether this is the best or not. There are many people who say that it is better to perform cardio before, and we are the ones who think that I am better after doing the exercises with weights.
Remember that when performing anaerobic exercises (are those where you use more strength and less breathing) we need a fuel that in this case would be the glycogen, and if we do the aerobic exercises (are those where you use less strength and more breathing), we spend it.
The conclusion is obvious, perform cardiovascular exercise before starting with the weights is never advisable. If the routine is not done correctly and intensely, muscle hypertrophy will never take place, or what in a less technical language we could translate as the fact that the process of growth of muscle cells and fibers (and so so much of muscle) will never come. And what is worse, if glycogen is depleted and amino acids are used to a greater extent as energy, the phenomenon of muscle catabolism (loss of muscle mass) could occur.
Always do your stretch before a short warm up and give the weights hard, after this you can perform the cardio without any problem to tone muscles