Muscles are simply made of fibrous tissues. These fibrous tissues are like elastic in nature just as same as rubber band. Our muscles consist of thousand's of small fibrous tissues which in collective makes muscle.
First of all, testosterone, growth hormones, insulin, etc... plays an important role in development of muscle. Now, the basic development of muscle occurs when muscle tissues/ fibers break's down or get's injured. Your body repairs those tissues/ fibers itself resulting in size gain/ mass gain.
By working out you are damaging your muscle tissue & also gaining muscle mass by consuming well nutrition diet. When we hit a muscle with certain weight the muscle get's breakdown, but on the spot, the feeling of blood rushing, the pump in your muscles, you get this kind of feeling because your muscle get's swelled up with excessive amount of blood.
No matter what part you are working out, but just by performing exercises you are providing excessive blood flow to that muscle.
So, workout really impacts on muscles by providing it with more muscle mass & less fat. It doesn't matter if your goal is to build muscle mass or loose fat, workout will always be neutral in both the phases or should i say in every phase.
No, because it's the only "weights" that will build your muscle more. The more weight you lift, the bigger you get, because when we lift heavy weight, our muscle breaks down a lot. After that it needs to re-build with good nutrition. The better nutrition we will provide, the better the results.
Now, if your goal is muscle building/ mass gaining than the weight plays way too important role in your daily routine.
But if your goal is just to be fit, or fat loss ? than yes, you can say that without weights you can loose those extra fat, those extra muscles & yes you might gain some lean muscle mass. But like i said, it all depends on your diet & on your workout routine.
See, to build you muscle all you need is protein, fats, carbs... If you are providing your body with all the essential elements that it needs than you can surely gain muscle. Now if you are thinking on how much muscle mass ? Than answer to that depends on how much you eat, how much you workout.
" In BODYBUILDING, no question has just one straight answer. Every question has many answers to it. So, if you are expecting straight forward answer to your problem, than you need to change your thinking towards bodybuilding. "
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