If the frequency is once a week, it will not be of substantial help to improve cardiopulmonary function. If you want to improve heart and lung function, exercise at least 4 days a week.

Speed and slope are all factors used to control the intensity of exercise, and the index of exercise intensity is usually reflected by heart rate. In order to improve cardiopulmonary function, your heart rate during exercise should be kept within 74%~84% of your maximum heart rate (220 years old).

I suggest you run for 30 to 40 minutes at a time, because you are thinner. Besides, you are now in the stage of gaining muscle. Long-term exercise consumes too much protein, and you can't gain muscle without protein.

It is very important to choose suitable running shoes and venues to protect hips, knees and ankles when running.

I suggest you learn the running posture in the video below. This is the running teaching video/v _ show/v _ show/id _ xmtg2mduxnzy4.html by Ryan Hall, the famous American half horse record holder.