Walter G George was a hugely successful runner and athlete. In 1886 he ran a mile in 4 minutes 12¿ seconds-a record that held for almost 30 years.He devised the '100-Up' Exercise as part of his training, using it to enhance his fitness and improve his running technique. In the early twentieth century he published details of the '100-Up' and they are now reprinted here in full for a new readership.The '100-Up' Exercise has seen a huge revival in the twenty-first century. It is used by many runners to improve their performance and develop technique, but the method can also be used by non-athletes to increase fitness and stamina. Best of all, it's an exercise you can do indoors or outdoors, at home or at work... in fact, almost anywhere.