I started mountain biking to strengthen my legs so that I could walk more steadily. I had to decide this was an adventure. When I was told, "I envy your determination!" I replied, "Don't envy my determination, join me for the ride."
Exercise doesn't have to be brutal. Find your starting point, the point that is right for you. From there, when it becomes easy, then slowly intensify it. Make adjustments for progress. This is what I had to do. Now I have begun strength training. I LOVE IT