I just started with the home study course. Even though I am in a fairly good physical shape (regular 20 min jogging, cycling), not overweight and only 33, I find standing even for 15 min very difficult. To begin with, it says in the course the knees should be slightly bent. Is that only for the first excercise or through-out the session? Or does it mean one should simply stand in a relaxed way? After a few minutes the soles of my feet feel hot and uncomfortable. Also, I find myself worrying that the blood stops circulating in my legs, thereby increasing the number of varices which I have already plenty of. Is this kind of standing for a long time just a matter of training?

You might be bending your knees too far. Try bending them a little less, and later bend them more. Watch the video again so you can see how bent Master Lin's are during the different exercises.

For your feet, try removing your shoes and socks if they get too warm. It could be the energy moving. I don't think blood stops circulating in the legs during the exercises. When concerned, consult your doctor.

Standing for a long time is a matter of training. If you cannot stand through all of the exercises, sit for a couple of minutes. During this time, either focus on your lower dantian, or continue doing the exercises in the sitting position.

Happy Day.