30-Minute Treadmill Workout

Be prepared to sweat with this killer treadmill workout [9]! Designed by the mastermind behind Equinox's Precision Running [10], you can tailor it to fit whatever level of fitness you're currently at by modifying the speeds however you see fit. Keep in mind the whole workout is intervals, so pace yourself in the beginning so you don't burn out too quickly.

Fat-Burning Plyo Circuit

If you're new to plyometrics or you have delicate knees, it's probably best to avoid this plyo circuit [11]. But if you're up for the challenge and you know your body is ready, you'll be damn proud of yourself for finishing this workout. From box jumps to jumping lunges, you'll feel this session everywhere.

Jump Rope HIIT and Strength-Training Workout

You'll get it all in this one workout [12]: HIIT cardio and strength training. Just grab a jump rope; the rest is done with your bodyweight. If you're sceptical about using a jump rope to get in a good workout, just trust us. You'll sweat your butt off.

20-Minute Cardio Kickboxing HIIT Workout

Get ready to burn major calories with this 20-minute kickboxing HIIT workout [13]. You'll do kicks, punches, and all kinds of lower-body HIIT movements that will tone you up and even help you burn more calories throughout the day.

Towel Abs

You don't need disc sliders for this exercise; just grab a pair of towels and get to work.

• Begin in plank position with two towels under the balls of your feet (or paper plates if you're on carpet).
• Slowly bend both knees in toward your chest while keeping your arms straight, shoulders over your wrists, and maintaining a flat, tabletop back. If this is too difficult, draw one knee in at a time.
• This counts as one rep.
• For a variation, draw both knees to your right foot, straighten your legs back behind you, then draw both knees to your left foot.
• This counts as one rep.

Elbow Plank

This tried-and-true ab exercise will target all your abdominal muscles.

• Start on the floor resting on your forearms and knees.
• Step your feet out one at a time, coming into a plank position.
• Contract your abs to prevent your booty from sticking up or sinking. Your spine should be parallel to the floor, with your abs pulling toward the ceiling.
• Hold 30 seconds, and work your way up to one minute as you get stronger.

Knee Driver

You'll feel the burn — in your abs and shoulders — from this bodyweight exercise, which also adds a boost of cardio.

• Begin in an elbow plank position with your abs engaged.
• Draw your left knee into your chest. Then step your foot back to the elbow plank position. Now draw your right knee into your chest and then step it back to the elbow plank position.
• This counts as one rep. Start with 12 to 15 reps, and do at least two sets.

Twisting Mountain Climber

Get ready to obliterate your obliques with the ultimate core move. Mountain climbers are especially great because they also provide intense cardio. Start in plank position and prepare to burn some major calories.

• Engage your core.
• Explosively bring your right knee up toward your left elbow while twisting your obliques.
• As soon as you return your right foot to the floor, explode with your left leg, pushing your left knee toward your right shoulder. The movement and transitions should be fluid, without pauses, in this exercise.
• Aim to complete 10 reps on each side for a total of 20 reps. Rest and then do one or two more sets.

Scissor Kick

Like reverse crunches, these target your lower belly and will strengthen your core.

• Lie flat on your back. Extend your arms so they're against the sides of your body with your palms pressing into the floor, or bend your elbows and place your palms under the back of your head. Bend your knees and draw them into your ribs. This will make it easier to pull your navel in toward your spine and actively press your lower back flat on the ground.
• Lift both legs straight up toward the ceiling, continuing to engage your abs and pressing your lower back into the ground. Keeping your core strong, slowly lower your right leg down toward the ground until it is a few inches above. Then slowly scissor your legs, lifting your right leg back up as you lower your left leg down toward the ground.
• This counts as one rep. Ten reps make a set; do at least two sets.

Double Leg Lift

On top of working your abs and obliques, this move also doubles as a great thigh toner. Plus it's a great modification for hanging leg raises [14], too.

• Lie flat on the ground with your legs extended straight up toward the ceiling. Place your hands underneath the back of your head. For added stability, place your arms out to your sides, allowing your palms to grip the floor (much like you would in a push-up position).
• Pressing your lower back into the ground, slowly lower both legs down toward the floor, then slowly raise them back up. If this is too difficult, lower them as much as you can or lower one leg at a time.
• Complete 10 to 15 reps.

Ball Pike to Plank

This killer move focuses on your lower abs as the bottom half of your body is in full control of the ball. First things first: make sure the ball is sized to your body; you should be able to sit on the ball with 90-degree angles at your hips and knees. If you don't have an exercise ball, use two sliders or paper plates on carpet to slide up to pike position.

• Start in a plank position with your hands directly under your shoulders and your shins on the ball.
• Do not allow your lower back to arch. Keep your feet, pelvis, and shoulders in one long line.
• On an exhale, pull your abs deeply to your spine and use your abs to fold your body in half, pulling the ball forward toward your hands as your pelvis moves up in the air.
• Your toes will move onto the top of the ball, and your back will become perpendicular to the floor, like a handstand. Allow your head to fall between your arms, keeping your neck long and in line with your spine.
• Lower yourself back into a plank position, and do not allow your pelvis to sag below your shoulders.
• Do 10 reps for two to three sets.

Russian Twists

Add weights to Russian twists to blast your front ab muscles, transverse ab muscles, lower back, and obliques.

• Sit on the ground with your knees bent and your heels about a foot from your butt.
• Slowly recline backward until you feel your lower abs engage. It is really important, and difficult, to keep your back straight, but don't let it curve.
• Place your arms out in front of you with your hands one on top of the other. Your hands should be level with the bottom of your ribcage.
• Pull your navel to your spine and twist slowly to the right. The movement is not large and comes from the ribs rotating, not from your arms swinging. Inhale through centre and rotate to the left. This completes one rep.
• Do 16 full rotations to complete a set.

Hanging Leg Raise

Master this advanced move, and you'll have those lower abs showing in no time. To modify, you can do this move with bent knees.

• Start by hanging on a pull-up bar with palms facing out, or use the ab straps and hang with your arms inside of them. Do use a box or bench if you need help reaching the bar.
• Pull your shoulder blades down your back to keep your shoulders away from your ears.
• Engage your abs as you fully extend both legs, lifting them up simultaneously with control.
• Lower your legs down slowly and return to the starting position. This completes one rep.
• Avoid swinging during this move to ensure you're really working your abs.
• Do two sets of 10 reps.

Battle Ropes

Using battle ropes is a fantastic full-body exercise: in addition to forcing you to engage your core, your entire body will need to kick into gear to stabilize you. On top of that, your heart rate will shoot up, which helps burn calories. Here are two variations to start with.

• Hold the ends of the ropes at arm's length so they are extended out in front of your hips.
• Keep your hands close together, about one foot apart.
• Bend into a semi squat position.
• Engage your core.
• Explosively raise both hands straight up into the air until they are about eye level.
• Bring your hands back down to hip height.
• Rapidly repeat this motion for one to two minutes.
• Rest and begin the next set.

Try to do three sets, with rest in between. Each week, challenge yourself by extending the time of each set.