Shares in Life Time Fitness Inc. rose sharply Thursday after the company's latest results beat expectations, shaped by efforts to keep members at its health clubs.

The company's third-quarter profit was flat, but revenue jumped 6.6 percent and so-called in-store revenue, what members spend on top of their monthly fees, grew more quickly than overall revenue.

"Moving forward, our member retention initiatives continue to be a primary focus as we improve our portfolio of unique programs and services," Bahram Akradi, Life Time's founder and chief executive, said in a statement. "We also continue to explore a REIT conversion and will provide updates on this process."

Life Time announced in August that it was exploring the spinoff of its real estate assets into a REIT, or real estate investment trust, as some major investors have urged.

Its latest results were negatively affected by a charge of 7 cents per share for the costs of exploring options for such a move. That was offset by a positive effect of 10 cents a share from the reduction of a contingent liability related to a previous acquisition.

Life Time's net income was $34.4 million in the July-to-September quarter, flat with a year ago. That amounted to 91 cents a share, or 88 cents excluding the one-time charges and gains, which is up from 83 cents a share a year ago. Life Time's base of diluted shares is down about 10 percent from a year ago.

Revenue was $336.8 million, up 6.6 percent. In-center revenue rose 11 percent.

At the beginning of the year the company had committed to opening six new centers, and the last of those is expected to open in Las Vegas next month.

Shares of Life Time closed at $50.90 per share, up $3.13 or 6.6 percent.

Net income the first nine months of 2014 was $92.5 million, or $2.35 per share, compared with net income of $95.7 million, or $2.30 per share, for the prior-year period.

Patrick Kennedy • 612-673-7926