Exercise is both an art and a science. 1) there are things that will work for you, but not someone else, (the art), and 2) there are things that will work universally for everyone (the science)
The number 1 principle of training is progression. In order to improve your fitness, you must provide your body with an exercise stimulus that it has not been exposed to before.
Similarly, the exercise stimulus must provide an element of overload. You cannot expect to lift 2 lbs of weight and get stronger. The exercise must be challenging. The stronger you get, the more you should do.
If you want to make your goals a reality, you cannot just ‘wing it.’ You need to have a well-thought-out plan that will get you closer to your pre-defined goal.
In order to repair itself, the body must then undergo a process known as anabolism. Without anabolism, there is no adaptation, and there is no progress.