1. Stand in the hack squat machine with your feet shoulder-width apart and your back against the pad. Your shoulders should be under the shoulder pads and your hands should be gripping the handles.

2. Slowly lower yourself down by bending your knees, making sure to keep your back straight and your chest up. Go as low as you can without letting your heels come off the platform.

3. Push through your heels to lift the weight back up to the starting position, straightening your legs as you stand up.

1. Start by holding a dumbbell in each hand. Stand up straight with your feet shoulder-width apart.

2. Take a big step forward with your left foot and lower your body until your left thigh is parallel to the ground and your right knee is just above the floor. Keep your torso upright and your chest out.

3. Push back up with your left foot to return to the starting position.

4. Perform the desired number of repetitions before switching legs.

1. Sit on the hamstring curl machine with your back against the pad. Position the stationary pad so that it rests firmly on your thighs.

2. Place your legs on the rounded pad so that your lower calves are resting on it, knees slightly bent, not overextended. You may have to adjust your seat back or height or the rounded pad position to achieve the proper set up.

3. Using your hamstrings, curl your legs back toward your body. Grasp the handles on the thigh pad for support.

4. Hold for a second and then, in a controlled motion, return your legs to starting position.

1. Stand with your feet hip-width apart and your toes pointing forward.

2. Slowly rise up onto the balls of your feet, lifting your heels as high as you can go.

3. Pause briefly at the top of the movement, then slowly lower your heels back down to the ground.

4. Repeat for the desired number of reps.

1. Attach a rope handle to a high cable pulley machine and kneel down facing the machine, with the rope either behind your head at neck-level or at forehead-level.

2. Grasp the rope handle with both hands and bring it to shoulder-level.

3. Engage your core muscles and slowly crunch your torso forward, bringing your elbows towards your knees.

4. Hold the contraction for a few seconds, then slowly release and return to the starting position.

1. Sit on the floor with your knees bent and your feet flat on the ground. Lean back slightly, engaging your core.

2. Lift your feet off the ground, balancing on your sit bones.

3. Twist your torso to the right, bringing your hands or weight towards the right side of your body.

4. Return to the center and twist to the left side, bringing your hands or weight towards the left side of your body.

5. Continue alternating sides in a fluid and controlled motion, engaging your core throughout.

1. Hang from a pull-up bar or a set of parallel bars with your arms fully extended and your palms facing away from your body.

2. Engage your core muscles and lift your legs up towards the ceiling, keeping them straight and together.

3. Once your legs are perpendicular to the floor, slowly lower them back down to the starting position, avoiding any swinging motion.

4. Repeat for the desired number of repetitions.

1. Lie on your back with your knees bent and your hands lightly touching the sides of your head. Lift your feet off the ground and bring your knees towards your chest.

2. Straighten your left leg while simultaneously rotating your torso, bringing your left elbow towards your right knee. Keep your shoulder blades off the ground.

3. Return to the starting position and repeat on the other side, straightening your right leg while bringing your right elbow towards your left knee.

4. Continue alternating sides in a fluid and controlled motion.

5. Complete the desired number of reps or time, then release your head, neck, and shoulders back to the ground, and lower your legs back to the starting position.