How many weeks post-sclerotherapy is it advisable to do medium to high intensity exercise?

I would consult with your treating physician regarding there recommended protocol, as everyone's may vary. I typically tell my patients they can resume walking that same day, and have them resume medium to high intensity workouts (avoiding as much abdominal recruitment) within 3 days of treatment. Of course, I do have my patients wearing compression hosiery 24 hours a day, 7 days a week after treatment (showering in them and blow drying them afterward).

We have our patients walking immediately. High impact exercise 2-3 days later, utilizing stockings as recommended.

No limitations after sclerotherapy in my practice - walk immediately upon going home, and do whatever you desire the same or next day. Must wear stockings for 3 months to cover the areas injected (thigh if there was sclerotherapy done in the thigh; knee length if sclerotherapy is limited to the areas below the knee). Avoid exposing the legs to sun for 3 months and use topical creams VenoQuin and VenoLucent. 

Sclerotherapy works immediately. Compression for 24-48 hrs.Normal activity immediately.Samir Shureih MD.FACSsshureih@msn.com

Following sclerotherapy I recommend compression for only 48 hours, resumption of all exercise immediately and return to normal activities.  The only restrictions I recommend are no hot tubs or hot baths for 5 days post sclerotherapy to avoid vasodilation and avoid sun exposure for at least 2 weeks post treatment or until any bruising subsides.  For bruising I recommend ice for the first 72 hours then heat.  Support hose do not have to be worn during exercise and showers can be done immediately after exercising.  I have been doing sclerotherapy for over 20 years and patients do very well with this protocol.