When is it safe to go kayaking and hiking after abdominoplasty?

Every surgeon has a different postoperative protocol.  It's best to speak to your surgeon because he/she may prescribe something different due to something specific in your case.
I usually tell patients that they can return to normal activity between 4-6 weeks.  I have them keep the binder on for at least 4 weeks. No heavy lifting for 4 weeks minimum. 
Usually at about 4 weeks, your body will tell you what you can and cannot tolerate. 

Dear Jlc0503,every plastic surgeon has his own postoperative protocol which he recommends to his patients. I would suggest you to discuss this with your plastic surgeon.Daniel Barrett, MD
Certified, American Board of Plastic Surgery
Member, American Society of Plastic Surgery
Member, American Society of Aesthetic Plastic Surgery

Hello dear!!
Thanks for the question and provided information as well.
I recommend my patients to wait at least 6 weeks before resuming their workout rutine (cardio, lift, etc.), but every case is different, so I suggest you to follow up close with your plastic surgeon.
Hope this is helpful. Good luck :)