All those New Year’s resolutions to get in shape appear to have helped lift Life Time Fitness‘ financials for the first three months of the year.

The company reported this morning that membership at its more than 80 fitness centers increased for the fourth consecutive quarter, with a nearly 15 percent increase in membership dues, compared with the same quarter last year.

The Chanhassen company’s profits were down slightly, however, to $15.1 million, compared with $17.4 million in 2008. That’s because many of those new memberships have been discounted, meaning the chain is getting less money from each member. Average revenue per membership was down 3 percent.