Jogging became popular in the early 1960s. It was the time when the dangers of heart disease were beginning to be acknowledged. People became aware that the comforts of modern life can actually kill them. With an affluent society and an efficient transport system, physical exercise became restricted. At the same time, with increasing competition and consequent emotional and social pressures, stress become part of people’s lives.
But then some joggers began dropping dead, and making more headlines. The problem was that some people who had not taken exercise for years had bought themselves training shoes and gone straight out jogging. Nobody had warned them that their hearts might not be able to take the sudden strain.
Meanwhile, a doctor in the United States Air Force was working on a concept of exercise that he called aerobics. It was eventually to provide safeguards for the incautious. The doctor’s idea was to slot the physical activities that people enjoyed most into a realistic fitness program. An individual could measure and control progress, thus avoiding the dangers of overstress while at the same time ensuring that the level of exercise was sufficient to show worthwhile improvement in physical condition. Aerobic exercise (the name is taken from aerobic capacity – the maximum amount of oxygen the body can process) is any activity that improves the efficiency of the heart and lungs. Using complicated laboratory equipments, the doctor measured the aerobic capacity of thousands of volunteers and produced an index of fitness based on the amount of oxygen processed in a minute. He discovered, for example, that an unfit man in his 40s could process only about 25 milliliters of oxygen per kilogram of body weight, while a fit man of that age would process almost twice as much.
After further extensive field research, the doctor worked out a correlation between effort exerted during different aerobic activities and oxygen consumption. In this way he was able to devise a system of points based on age, distance covered, time taken and frequency. To achieve aerobic fitness, a score of thirty points a week was required. The scoring is precise. For example, at the start of training a man over 50 would, by jogging 1 mile in about 18 minutes five times a week, earn a total of 5 points toward the 30 he needs ultimately to attain every week. By the 6th week, jogging 1 mile in just under 14 minutes five times a week, he would earn 10 points. At the 16th week, with increased distance and reduced time, his total marks would be 34. The result was a tailor-made program for the jogger, runner, cyclist, swimmer, and amateur sportsman. The findings were published in the doctor’s book, “Aerobics”. The second edition of the book, “The New Aerobics” went into 20 printings in less than 5 years.
