The One Thing: The Surprisingly Simple Truth Behind Extraordinary Results

by Gary Keller

So, how long do you have to maintain discipline? Researchers at the University College of London have the answer. In 2009, they asked the question: How long does it take to establish a new habit? They were looking for the moment when a new behavior becomes automatic or ingrained. The point of “automaticity” came when participants were 95 percent through the power curve and the effort needed to sustain it was about as low as it would get. They asked students to take on exercise and diet goals for a period of time and monitor their progress. The results suggest that it takes an average of 66 days to acquire a new habit. The full range was 18 to 254 days, but the 66 days represented a sweet spot—with easier behaviors taking fewer days on average and tough ones taking longer. Self-help circles tend to preach that it takes 21 days to make a change, but modern science doesn’t back that up. It takes time to develop the right habit, so don’t give up too soon.