Anjelina is a young sprinter looking to move faster out of the blocks. Pro Ashlea demonstrates her acceleration techniques, and Dr. Heather explains how gravity, the invisible force of attraction, affects sprinters. Everything that has mass has gravity, and the bigger the mass, the more gravity it has; so Earth, which is huge has much more gravitational force than our bodies. Ashlea starts by leaning at a 45° angle, so she can use her centre of gravity to get top acceleration. Track and field began in Greece in 776 BCE when a foot race was run in a stadium at Olympia. In the next 1200 years, jumping and throwing events were added to the quadrennial Olympic games.