24 days post gynecomastia surgery, how many weeks till I can move around freely without stretching my scars?

I ask my patients to restrict strenuous activity for 4-6 weeks, though every surgeon will have their own preference.  The concern with regard to the scar is that at this early post op stage your incision is being held together by some dissolvable sutures and just more than 3 weeks of collagen growth.  There have been studies done on the tensile strength of maturing scars, and it takes months to develop enough strength to resist stretching.  Please discuss with your surgeon, and when exercise and stretching is permitted, consider keeping skin edges together with steristrips or paper tape. 

Thank you for sharing your question and photograph and congratulations on your procedure.  At three weeks I think you should be fine to start increase your upper arm range of motion and daily activities with little consequence to your long-term scar appearance.  Remember it will take a year or longer for your results to fully mature and fade.  Always best to ask your surgeon their specific recommendations, however, as they know the full details of your operation.

At this stage, stretching is usually recommended if the healing is going well.  Contact your surgeon for his post operative instructions.