Waist training uses firm compression to slim your midsection. Many garments are also designed to increase thermal activity for added perspiration around your core, reducing water retention, particularly if you waist train while working out. You will look slimmer instantly by putting your trainer on. For many women, it’s an instant confidence boost, as it accentuates your natural curves and makes it easier to achieve an hourglass figure. How dramatic your results are depends on your fitness routine, how frequently you do it, your body type and your lifestyle. And don’t forget, wearing a waist trainer also helps you maintain good posture, making you look taller and leaner.