We are constantly being told to eat less salt. Can it be harmful to eat too little salt?
In our society there's probably no chance of eating too little salt. It is in so many foods that we would have to be dangerously faddy to avoid it. In less developed countries, there are isolated mountain valleys where people have access to very little salt, eating far less than we could possibly do on a normal diet. They don't seem to suffer, and are just as healthy as those in nearby valleys where the rocks and soil contain more salt. People with rare kidney diseases or for whom mistakes in drug treatments have made them salt-deficient feel sick and dizzy, have low blood pressure and may lapse into stupor or even coma. They are extreme cases, and this would not happen to a normal person reducing salt.
Does jogging harm your knees?
It shouldn't if you wear the correct shoes with cushioning under the soles and heels. It probably will if you already have dodgy cartilages or the beginnings of arthritis. Pain at the side of the knee next to the other knee is common when you start and is usually just muscular strain. If the inside of the knee hurts, it gets stiff, swells, gives way or locks, then you need to seek advice and to choose another exercise. Walking might be better, and swimming helps, though you have to swim for longer than you walk to get the same benefit. If you prefer to cycle, make sure the saddle is high enough to allow a near-straight leg at the lowest point of the pedal.