James F. Fixx (April 23, 1932–July 20, 1984) was the author of the 1977 best-selling book, The Complete Book of Running. Best known as Jim Fixx, he is credited with helping start America's fitness revolution, popularizing the sport of running and demonstrating the health benefits of regular jogging.
Fixx was a member of the high-IQ club Mensa and published three collections of puzzles: Games for the Super-Intelligent, More Games for the Super-Intelligent and Solve It! The back flap of his first book says: "...He spent his time running on the roads and trails near his home, training for the Boston Marathon."
Fixx started running in 1967 at age 35. He weighed 240 pounds (110 kg) and smoked two packs of cigarettes per day. Ten years later, when his book, Complete Book of Running (which spent 11 weeks at No. 1 on the best-seller list) was published, he was 60 pounds (30 kg) lighter and smoke-free. The book inspired millions of people. In his books and on television talk shows, he extolled the benefits of physical exercise and how it considerably increased the average human being's life expectancy.
The cover of Jim Fixx' book, The Complete Book of Running, featured Fixx's muscular legs against a red cover. The book sold over a million copies.
In 1980, Fixx wrote a follow up book entitled Jim Fixx's Second Book of Running: The Companion Volume to The Complete Book of Running.
In 1982, Fixx published Jackpot!, the story of what happened after the publication of The Complete Book of Running when he experienced the "Great American Fame Machine", becoming richer and more celebrated than he could have imagined. In one account, he noted an experience of being on a TV show with George Harrison, and noticed that Harrison was not sitting down in the "green" room. Upon inquiry, Harrison said that sitting down wrinkles the pants. He had become a guru of the running boom.
Maximum Sports Performance, published posthumously, discusses the physical and psychological benefits of running and other sports, including: increasing self-esteem; acquiring a "high" from running; and being able to cope better with pressure and tension.
Fixx died at the age of 52 of a fulminant heart attack, after his daily run, on Vermont Route 15 in Hardwick. The autopsy revealed that atherosclerosis had blocked one coronary artery 95%, a second 85%, and a third 50%. Some who opposed his beliefs said this was evidence running was harmful. However, Fixx came from a family where the men had poor health histories. His father suffered a heart attack at age 35, dying of a second at 42.
A carved granite monument—a book with an inscription to Jim Fixx from the people of northeast Scotland—now stands in Hardwick Memorial Park, in Hardwick 
The song "I'm Jim Fixx and I'm Dead Now" is a song by Australian band The Fauves found on their album Nervous Flashlights. The song details Fixx's death during exercise and is based on the famous Bill Hicks routine.