Every January, zillons* of people start a new fitness program and the gyms fill up. By February, most of the newbies are missing workouts and by March things are pretty much back to normal (to the relief of the regular gym-goers). It doesn't only happen at the start of each new year, although that's a reliable occurrence. It would be nice to have statistics on the median lifespan of a new fitness routine. I'm confident it would be less than 30 days.
So what goes wrong? Why do so many people quit? Often, it's a case of doing too much too soon.