Once you start being physically active, you’ll begin to see results in just a few weeks. You may feel stronger and more energetic than before. You may notice that you can do things more easily, faster, or for longer than before. As you become more fit, you may need to make your activities more challenging to see additional results. Faster result are also compounded by following  the right diet. Research shows that changes in the structure of your muscle can occur in as little as two weeks after starting a training program. How fast and how much you increase your strength depends on your initial level of strength and your potential for improvement.