Hi jearef,
You are asking a tough question for which there is no absolute answer. There are so many variables to consider. Factors in the equation include your fittness, SKILL OF SURGEON, frame of mind, type of prosthetic. Then it is up to you and your surgeon as to what you want to do with your new hips. That said, I can only tell you how my THR worked.
I had simultaneous bilateral THR 2.5 yrs ago at age 53. Severe osteoarthritis. I was very fit and athletic at the time although I had to quit running for 6 months before surgery from pain. I had an outstanding surgeon who spent a lot of time trying to understand my hopes for a succesful surgery. Mostly I wanted to return to a very active lifestyle. He chose the type of prosthetic he felt would hold up the best for me. I trusted him, and I now sport a lovely pair of Stryker highly crosslinked poly/titanium hips. My surgeon uses MIS posterior approach(no muscles cut). I was not a candidate for resurfacing due to the severe deterioration of my hips, but if I were you, I would look into that procedure too.
I had a 2 month wait for surgery, during which I cut way back on my cardio and concentrated on weight training, so that I went into my surgery really lean and strong. The surgeons loved me!!

I was home in 2 days, just blowing the PT away and my entire recovery was record breaking. But I had a very postive outlook and worked my butt off. Not easy, but what I needed.
I was able to return to just about all my athletic endevors within weeks, albeit at a very tentative pace to begin with. After a year, you would have no idea I have THR. I mountainbike, rollerblade, hike, kayak, ski both downhill and x/c hard, competetivly ride in hunter/jumper/event shows, clean stalls and heave bales. My work is taking care of and grooming dogs and cats, so I lift 90 lb dogs into a raised tub. I still run some, but low mileage on soft surfaces with cushioned shoes. I do have to run really fast with the horses sometimes.
So it is possible to do all that you want following THR. I realize that I may be wearing out my hips faster than if I baby them, but that is my choice and I accept the responsiblity of that. On the other hand, my stong muscles, tendons and ligaments are helping to protect those babies too. At my 1 yr checkup my OS was totally thrilled with how they looked at gave me the complete go ahead or to quote "go for it". I am very glad I did not wait anylonger, in fact wish I had done it years ago. Your hips will only continue to deteriorate making it a harder surgery with less chance of success. Do find a great surgeon and DO keep in shape. Stay postive, life is wonderful with painfree hips!!!
Andrea