1. Find a sturdy doorway that has a flat, wide doorframe.

2. Stand facing the doorway and hold onto the sides of the doorframe at chest height.

3. Lean back as far as you safely can while holding yourself stable, keeping your body in one straight line and your heels planted on the ground.

4. Engage your back muscles to pull your body back towards the doorframe, squeezing your shoulder blades and lats together.

5. Pause briefly at the top of the movement and then slowly lower yourself back to the starting position.

1. Stand in a doorway with your feet hip-width apart and your arms extended straight out in front of you, gripping the doorframe on either side.

2. Engage your core and glutes to maintain good posture and stability.

3. Slowly pull your body towards the doorframe, bending your elbows and keeping your upper arms close to your sides.

4. Pause briefly at the top of the movement, squeezing your biceps.

5. Slowly lower your body back down to the starting position.

1. Lie face down on the ground, toes pointed, ankles touching the ground, arms extended forward, like Superman in flight, palms down, touching the ground.

2. Pull one arm and the opposite leg off the ground by engaging your glutes, shoulders, core, and back. They should rise up 2-3 inches.

3. Ensure that your arms are also fully contracted.

4. Hold this position for 1-2 seconds.

5. Slowly lower your arm and leg back to the starting position. Repeat, using the other arm and opposite leg.

1. Stand straight up with your arms relaxed by your sides.

2. Keeping your arms straight, raise them overhead and slightly out to the sides to create a Y shape with your body.

3. Hold the Y position for a few seconds, then slowly lower back down to the starting position.

4. Repeat for the desired number of reps.

5. To increase the difficulty, you can hold light weights or resistance bands in your hands during the exercise.

1. Start in a plank position with your hands directly under your shoulders and your body in a straight line.

2. Keeping your arms straight, retract your shoulder blades by squeezing them together. Your torso will move 2-3 inches towards the ground.

3. Reverse the movement by pulling your shoulder blades apart. Your torso will move 2-3 inches away from the ground.

4. Pause at the top of the movement, and then repeat the flow for the desired number of reps.

1. Begin by standing tall with your feet hip-width apart.

2. Raise your right knee up towards your chest, while simultaneously lifting your left arm up towards the ceiling.

3. Lower your right leg and repeat the movement with your left leg, while raising your right arm up towards the ceiling.

4. Continue alternating legs and arms, moving at a quick pace.