I started weight training in undergrad (kinesiology classes) and kept it up through DS (PT job at Gold's Gym) and still do it currently. It helps that I have a weight room in my home. Free weights. Machines. Bands. As I've aged .... I don't lift heavy, heavy weights like my younger years. Now I use less weight ... more reps... full range of motion. Due to our poor sitting posture .... it helps to strengthen the lower back, hams and stomach. Anything to keep the pelvic girdle from tilting forward causing excess curvature of the lower spine area. Keep your body weight down also. At 55 yrs old .... I'm pretty fit and experience no back issues whatsoever.