Ok thank you for the advice
Please tell your friend to NOT exercise while he has a DVT; the blood clot could break loose and have devastating effects, including death. The anticoagulants are given to reduce the clot and help prevent others from forming. He should not exercise until cleared from his physician.
Clots can form from lack of activity, like sitting too long, and are frequently associated with traveling long distances in a car without getting out and walking every few hours.
Once he is released by the doctor to participate in physical activity, may I initially suggest walking, bicycling and/or swimming.
Cheyenne_08 is correct that patients are asked to limit intake of foods containing Vitamin K. Your friend should talk to his doctor or pharmacist about this; they can provide a list of foods. Believe a person should not eat large amounts of leafy, green vegetables or certain vegetable oils, such as soybean or canola, that contain large amounts of vitamin K. Juice or products containing cranberries should be avoided. In short, he should talk to his doctor about any dietary changes before losing or gaining weight.
Hope this helps and best wishes for your friend. It is nice you care enough to help him.
When I was recovering from DVT my doctor told me not to exercise. He told me that the blood clot could break loose and move...however, I had nine blood clots in my leg so I am not sure if that is different if you only have one. Also, do not eat foods with Vitamin K, that counteracts the anticoagulant.