If your body has adapted to the long-term vegetarian state, there should be no problem, but as a fitness enthusiast, the requirements for diet are very high. Simply put, it means less oil, less salt and more protein, and the intake of carbohydrate fruits and vegetables should keep up, at least to meet the needs of the body. I think vegetarianism will mainly affect your intake of protein, but I wonder if you can eat eggs. If you can, the problem will be solved. If you can't eat eggs, I suggest you eat more beans, because some protein powder is extracted from soybeans, which should also meet your physical needs.