hk
If you aren't exercising enough to "stress" the muscles, you won't gain muscle mass. If you aren't exercising enough to burn the extra calories of the supplements you'll gain fat.
1) It strengthens your muscles/tones your body. 2) Enough of it, will change your fat into muscle. 3) It improves your muscular endurance, if you do it on a regular basis.
By saving a few dollars every week, Sam steadily saved enough to buy a new bike.
If you lift heavy enough you get micro tears (muscle soreness). While you are exercising your muscles burn food to make ATP which allows your neurons to tell your muscles when to contract. The byproducts of this metabolizing of food molecules makes it harder for your muscles to keep contracting. Lactic acid (a byproduct) builds up and burns.. Well, its a vague answer for a vague quesiton :P
When muscles work without enough oxygen, they produce a byproduct called lactic acid.
It's a build up of lactic acid. The muscles cannot process the waste products (from rapid exercising) quickly enough, and this builds up in the tissues as lactic acid. Eventually the levels get so high that the muscles seize-up.
yes
Yes, it can, if you don't stretch the muscles enough before exercising. It can also happen if the exercises put too much strain on the arms - for instance, in weight training before you have become accustomed to the weights.
Enough.
The muscles do not have enough oxygen for aerobic respiration.
I think it's because of a process called fermentation
The muscles do not have enough oxygen for aerobic respiration.