The wisdom is now 30 minutes 5 times a week. I went to my doctor because they wanted everyone to have a heath check. I have a good pulse rate, good blood pressure, right weight etc., but when I told her I swim 1km twice a week, play 40 mins squash per week, walk into town instead of drive, work out with weights at home (if I get the time), she said "you don't do much exercise then, do you?"
Most people I know exercise by putting food in the microwave, operating the TV remote control and lifting a pint glass - I'm one of the fittest people I know and the doctor told me I'm lazy!!
So now I run 3 times a week too