When can I start with regular exercising at the gym?

Thank you for your question. I always recommend to my patients to start exercises tend six weeks after PO, gradually: first, gentle walks without sweating, then, you can go to the gym to do aerobics, and, after four months you can stats with machines exercise and start with light weights, and, if there are no problems, only six months after PO may charge "free weights".
Respectfully,Dr. Emmanuel Mallol Cotes.

I generally advise that patients wait at least 3 weeks before they start exercising again. Please make sure to start off slowly. Sinc you're at 5 weeks, you should be okay.However, you should follow your surgeon's instructions as they may have different guidelines.

Resuming exercise too soon after liposuciton can increase swelling (edma) and possibly even cause small areas of bleeding that produce firm hard bumpy areas. To minimize this exercise should be avoided for 3 weeks 

Now that it has been five weeks after your liposuction, you can probably return to your preoperative exercise regimen, slowly, and with your surgeon's approval. I doubt there would be any harm at this time if you were to resume an aggressive exercise program.

Thanks for the question.

Generally it is best to to follow your surgeon's recommendations.

For my patients in your situation  strenuous exercise can be started at about 1 month after surgery.  I would suggest that you “start slow” and listen to your body (look for signs of swelling after workout).

I hope this helps.