I used to take karate a few years ago when I was 13 and at my peak, I was able to do about 50 pushups in one try. I stopped karate and now I have been doing a lot of bodybuilding, and it has been working pretty well for me. The problem is, I can barely pump out 8 pushups now because my triceps, forearms, and shoulders get incredibly weak and shaky. It's the feeling that you have been working out too long and you haven't eaten anything that day. But I eat almost non stop nowadays and I'm a lot more fit than I have ever been. My dad told me that it could be because I'm 16 and my body needs a lot more energy, but I'm not too sure. Even when I don't workout a lot, my arms get really shakey.
Do you know whats going on and what I can do to fix it?