Many people say that if you want to grow muscles, you should run first and then do strength training. Actually, I don't think it matters much. Because running is nothing more than consuming your own fat. Reducing fat will make your muscle lines look better. But if you are thin, I believe that the fat content will not be much. So it has nothing to do with running or not. From my personal experience, I actually think fitness is a long-term physical exercise, not a short-term one. You can see some results in time. If you want to keep fit, you must stick to fitness training, specify a good training plan and find a better training atmosphere. If you persist in this way, I believe that after hard training, you will gain something in less than 2-3 years. In the meantime, remember one thing. Don't compare with others, because the result of comparison is that you will be very painful and disheartened. Take yourself for example.