LA's Hottest Power Pilates Workout Comes to Phoenix! Invented by celebrated international fitness expert Sebastian Lagree, SPX Fitness is the fitness regime of choice by Hollywood's elite. SPX is a unique fusion of pilates, cardio and strength training. With the state-of-the-art Megaformer™, you get the optimum full-body workout. Stretching. Lengthening. Tightening your core…all in 50 minutes. Your first class is free. What are you waiting for?