In 2019, Google measured the effect of two-step verification across hundreds of thousands of real hijacking attempts. Adding a phone number to receive an SMS code blocked 100% of automated bots, 96% of bulk phishing campaigns and 76% of targeted attacks. An on-device sign-in prompt did even better. Turning it on takes two minutes, making it one of the best effort-to-protection deals online.
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.