I am delighted that major luminaries including Professors Frank Booth and Paul Hodges have agreed to share their wisdom in this issue of BJSM. Professor Booth’s millennium review, “Waging war on modern chronic diseases”,1 is compulsory reading. It clearly trumps Machiavelli’s The Prince for top spot among the Great Literature; Macca never made it onto PubMed nor did he get cited 187 times for 1 paper in 8 short years. In his magnum opus, Professor Booth provides incontrovertible evidence that physical inactivity causes medical costs of $US 1 trillion (yes, trillion, that’s a thousand billion) annually in the USA alone. Don’t just skip over that number—it happens to equal the estimate for the projected deficit of the USA in 2009. So with just a 12.5% reduction in the cost of physical inactivity, President Obama could have it all paid off by the time he leaves the White House in 2016. Not bad. My point? If you are having trouble justifying the importance of physical activity to a patient, government representative, Dean or President/Vice Chancellor, just slap Professor Booth’s paper on the desk and remind the person that a trillion is 16 times the current population of the planet. …