Will youngsters have a leg to stand on at 80?

‘Will youths in cars, or on electric bikes and scooters, be able to walk upstairs, let alone run, when they’re my age?’ Photograph: Dusica Paripovic/Getty Images/Moment Open

As an 80-year-old, I can testify that three years of daily step exercises, as advised by a physio, builds leg muscles, taking pressure off the knees while aiding cardiovascular health (Embrace the climb! How stairs can super-charge your fitness in seconds, 10 October). Will youths in cars, or on electric bikes and scooters, be able to walk upstairs, let alone run, when they’re my age?
Rowan Roenisch
Leicester

• One would have thought that Arnold Schwarzenegger would know his arse from his elbow, or his calf from his hamstrings. “Calves are basically the biceps of the legs,” he proclaims (Arnold Schwarzenegger’s seven big life lessons, 9 October). The biceps are the elbow flexors, and are equivalent to the “hamstrings” of the legs, which primarily flex the knee.
Noel Cameron
Emeritus professor of human biology, Loughborough University