Some people out there share the philosophy of "No Pain, No Gain" when it comes to physical fitness. The idea of pushing yourself beyond limits to build strength, stamina, and be at the top of your game. I personally, do not believe in this concept, at least not for me. Yes, I see the need for someone training in a sport or competition to believe in this concept, in fact I can see how it would be the best way for improvement. But, my only goal with exercise is to stay healthy. And pushing myself to the point of pain will not have the same benefits as it does for others. The risk for injury is too great. The risk to end up hurt and unable to exercise is too great. Its not worth it for me.
Now that is not to say that I don't work hard. I know I am getting in a good work out when my heart rate is increased, my breathing is a little deeper, and I break out into a sweat. I don't consider this "pain." These are just indicators to me that my body is working hard and I am benefiting from the exercise. When I lift weights, I do enough reps to feel a slight burn in the muscle. Again, not until I feel pain, but just enough to know there is a benefit. With this, I know that I may never get any stronger or be able to run for an endless amount of time or distance. Honestly, no matter how hard I work out, I still can't go up a flight of stairs without loosing my breath. But this is what works for me and as long as my PFTs don't drop and my back does not hurt, I don't see any reason to do anything different.