This process of muscle growth will not last long, nor will it be obvious. Don't worry about getting thicker. Don't forget that the outer layer of fat is still burning and thinning, and muscle growth will be slow when the body adapts. If it was so easy to grow, fitness wouldn't be so painful.
If it hurts badly, you'd better rest first to avoid injury. But in general, if you catch a cold, you should do more aerobic exercise to warm up, such as jogging, cycling, aerobics and so on. Through constant exercise and sweating, you can get rid of a cold.
The best way to lose fat without gaining muscle is to do aerobic exercise for a long time, such as jogging for more than 45 minutes. If you can't last that long, you can switch between running and walking, but the time can't be less than 30 minutes. A typical example, let's see which athlete is the thinnest. The answer is that long-distance runners, especially women, have thin legs. It is because the human body begins to consume fat after continuous aerobic exercise for more than 30 minutes, and begins to consume muscle after more than 45 minutes. Therefore, generally speaking, if you want to lose weight, you must stick to regular aerobic exercise for 30-45 minutes. If you want to lose your muscles, it will take longer, but you should do what you can. If you exercise too much, you will faint.