I am nearer to 60 than 50 and hampered by a lumbar spine scoliosis and an RTA but never giving up.....Pilates sessions to follow from anywhere using exact content included in my class delivered to all abilities and over a 50-year age range for more than 20 years. Pilates is functional and promotes correct postural alignment through strength gain in core muscles. This enables protection for the back and other joints and minimises or prevents a host of other health issues which result from poor postural alignment. Good postural alignment also optimises range of movement resulting in the ability to improve flexibility and general muscle strength and all these elements are included in my classes. Finally, Pilates is incredibly relaxing..... So give it a go, definitely complete the mobility and flexibility exercises within your own range and develop over time. As for the strength elements rest if you need to at first, keep with it and you will get there. Enjoy.