We've been fans of Australian personal trainer Emily Skye, creator of the F.I.T. programs, ever since we first stumbled on her crazy-motivating Instagram account. (She also gets really real on Snapchat, making her one of the Fit Girl Snapchat Accounts You Need to Be Following.) So when we had the chance to shoot a workout with her in our studio, we jumped on it. While Skye's program includes both gym and at-home workouts, we had her create a high-intensity workout that will tone your entire body sans equipment. (Translation: You have no excuses.)
How it works: Perform each exercise for 30 seconds back-to-back, without resting in between. When you get to the end of the circuit, rest for 30 seconds, then repeat all five moves again. Perform five rounds if you're a beginner, or up to 10 rounds if you're more advanced.
Stand with your feet shoulder-width apart (or slightly wider), toes slightly pointed out. Engage your core, keep your shoulders down and back, and hold your head in a neutral position. Squat down, squeezing through your glutes. Come up half-way, lower back down again, and then lift all the way up, squeezing your glutes at the top.
Stand with feet about shoulder-width apart with your core engaged. Crossing one leg behind the other, lower your body straight down until both knees are bent at 90 degrees. Squeeze your glutes before you come back up to starting position. Repeat on the other side.
Begin lying on a mat with your back flat on the ground and core activated (bring your belly to your spine). Lift your legs up in the air, then slowly lower them down, keeping your back on the ground the entire time. Bring knees in toward chest, then back up again and repeat.
Begin with your hands slightly wider than shoulder-width with fingers spread out. Get on your toes and perform a toe push-up, making sure your butt's tucked in, your neck is tall, and your core is tight. Come down, then return to the top. Perform on knees if needed. (Want to master the push-up? Try our 30-day challenge.)
Begin in push-up position with your core tight and butt tucked in. Pull right knee up to touch right elbow, then pull left knee up to touch left elbow. Continue alternating.