Stainless steel is tough, inert and easy to care for, but it's a poor heat conductor: about 16 watts per meter-kelvin, versus nearly 400 for copper and over 200 for aluminum. On its own, it would create hot spots right above the flame. That's why most stainless pans have an encapsulated base: a disc of aluminum or copper sandwiched inside to spread the heat.
Chlorine on its own is fairly gentle. But when it combines with urine, sweat and other grime from swimmers, it forms chloramines, which cause stinging eyes and that classic 'chlorine smell'. A well-kept pool barely smells at all. Shower before you swim and never pee in the water.
Muscle mass slowly shrinks with age, putting independence at risk. But in 1990, a study had nursing home residents aged 86 to 96 train their legs for eight weeks: their strength more than doubled. Muscle responds to training at any age. Getting up from a chair without using your hands is already an exercise.