Diet Trends

New Year’s resolutions to exercise waver toward late January, data show

People with the noble New Year’s resolution to work out or work out more should mark their calendars: That resolve starts to waver in the third week in January, data shows.

The pattern shows how difficult it is to make a new habit stick.

Attendance is a delicate part of a gym’s business. Gyms need new members but face regulars who complain about crowds, waits and the poor etiquette of January newcomers.

Check-ins on Facebook to facilities with “gym” or “fitness” in the name drop 10% in February, according to two years of Facebook data. The decline starts as early as the third week in January, Facebook researchers say. This dip comes after a more than 50% surge from December as people chase vows to lose weight or get fit.

It takes about 66 days to form a habit, according to a 2009 study by researchers at University College London.

Click for more from The Wall Street Journal.