Flexibility is important for injury prevention, mobility, and overall health.
Be sure NEVER to stretch muscles that are cold. You need some form of warm up first. Never bounce.
You should engage in a balanced wellness program, and a heart healthy diet, so you can grow old gracefully. Every program should include both resistance training, and cardiovascular training, as well attention to diet.
Know your blood pressure. You can google on "blood pressure chart" to see ideal ranges.
Know your heart rate and get so that you can train within your target zone.
Know your blood chemistry. In particular, a total cholesterol ratio to HDL ratio should be LESS than 4.5.
Keep your calories up, so you can maintain intensity, and stay anabolic, and get active. Not only will it improve the quality, and length, of your life, but, folks will treat you differently, and you'll feel better; be sick less.
Don't forget, only muscle and organs, burn calories at rest. More muscle means it's easier to eat more calories and not get fat. (Of course, it's not that simple because some folks have different microbes and endocrine levels, but, in general, more muscle means you not only have stronger bones, a better A1C, but, also that you can consume more.)