Special cells in your retina tell the brain's master clock that it's daytime, which keeps your whole 24-hour rhythm on track. Morning light shifts the clock earlier, making it easier to fall asleep at night. Even on a cloudy day, outdoor light is far brighter than office lighting. Step outside soon after waking: it's the easiest clock adjustment there is.
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.