When you are fit you have a lower probability of events leading to trauma because you have better balance, reaction time, and strength when needed.
You can see this from the inverse too: as you age all of those factors (muscle strength, reaction time) diminish, as do other issues (osteoporosis) so falls become both more frequent and more serious.
Yes, you can be hit by a car at any age, and some fitness enthusiasts engage in activities that can lead to sudden injury (e.g. skiing). But in general, the OP is correct.
You can see this from the inverse too: as you age all of those factors (muscle strength, reaction time) diminish, as do other issues (osteoporosis) so falls become both more frequent and more serious.
Yes, you can be hit by a car at any age, and some fitness enthusiasts engage in activities that can lead to sudden injury (e.g. skiing). But in general, the OP is correct.