 Planet Fitness Inc. PLNT, -7.85 posted better-than-expected profit for the first quarter, while revenue fell slightly short as the franchisor and operator of fitness centers announced plans to expand to New Zealand and open its first centers in Mexico. The company posted net income of 16.5 million, or 19 cents a share, for the quarter, up from 5.6 million, or 7 cents a share, in the year-earlier period. 