Vigorous exercise over 65 is good!
Recent research shows that even at the age of 65 (+/- 8.9 years) vigorous exercise can reduce the risk of low back pain (LBP). One of the more common errors we see in low back pain patients is that the exercises they use are too intense. Yet this study suggests vigorous exercise is good, so what gives? It's the ramp up phase. I often tell patients "it's not the exercise that set you back, it's the intensity or duration". Sure, there are exercises that simply are the wrong choice for some people, but more often than not it's one of those aforementioned variables that cause the problem.
This research just expands on a growing base of knowledge that basically suggests age old axiom "use it or lose it". That is meant to suggest doing things that are required in life, and sometimes strenuous physical activity is required. The best way to prepare for that is to do just that, albeit in a structured and ramped up manner. Not only will that allow you to do it safely, it will improve you overall ability to function and apparently it will reduce your risk for LBP as well!