Is it safe to go back to Kickboxing 4 weeks after Breast Augmentation?

This question can only be answered by your operating plastic surgeon.  I would wait to see him or her to get the definitive word on your return to kickboxing.Earl Stephenson, Jr, MD, DDS, FACS

Most plastic surgeons will recommend that you wait at least eight
weeks before resuming any intense physical activity or heavy lifting,
especially if it involves use of the pectoral muscle.  You may be able to resume before that
eight week point depending on how much stress the activity puts on the chest
and arms.  I would encourage you to be
patient and take time to heal, and definitely wait until your plastic surgeon
gives you the go-ahead before resuming physical activity. 

One month postop is about the right time to resume physical activity, but I usually advise patients to build their activity level back up gradually. Not even considering the surgery, you have been out of your class for 4 weeks and if you went straight back in at the normal level of intensity, you would really feel its effects. Add your postop scenario onto that and you might feel even worse. So go back to your class, but let the instructor know that you are going to take it very gently. Perhaps more kick and less box until you have gradually built back up to your preop peak.

I usually allow patients to go back to light aerobics within 3-4 weeks and heavy lifting or activities like kickboxing within 6-8 weeks provided that they have healed well.

 Timing to  return to specific types of exercise will vary from one patient to another. I would suggest that you gradually ease back into the strenuous aerobic exercise 4 to 6 weeks postoperatively, assuming that you are doing well and there have been no complications. Use common sense, listen to your body, and gradually resume previous activity. In my practice, I ask patients to avoid contact and strenuous exercise involving the  pectoralis major muscles ( such as push-ups, bench press,   burpees,  dancing on a pole…) for at least 3-6 months.  Best wishes.