I can't say I ever gave my shoulders and back a second thought until I started a month-long fitness challenge [1] and realized after day one, I was struggling on any movement that engaged my upper body. Since then, I vowed to devote some time getting not only my arms in shape but also to strengthen those shoulders and back, so I could rock the UA Infinity Low Sports Bra [2] ($35) confidently and, most importantly, reduce my risk of potential injury.

"The shoulders and back contain the origin of the arm muscles and ligaments," explained NASM-certified personal trainer and cofounder of Grassroots Fitness Project [3] Heather Gunn Rivera. "If you don't strengthen the origination and insertion points of the muscles, then you are susceptible to injury."

To challenge myself, I asked Rivera to share a solid sequence of moves that will help me get those shoulders of my dreams. The kicker? No weights allowed. I'm only operating with five pounders in my apartment, so I knew bodyweight was the way to go for me. Thankfully, she came through with five simple moves that are kicking my butt — or should I say back.

Push-Up

• Start in the plank position with shoulders over wrists, keeping hands in line with chest and just outside shoulders. Pull up on the knee caps to tighten the quads to engage the whole body.
• Inhale and hold the breath (only if you are not pregnant) through the down portion of the push-up. Keep the push-up slow and controlled while maintaining your elbows at a 45-degree angle to the body and keeping the hips high.
• Exhale and press back up. The press up should be half the time it took to lower the body.

Push-Up Plus (no elbow bend)

• Start in the same position as the push-up. With your hands out in a plank position — without moving the hands externally — rotate the shoulders by turning the elbow pits forward. Maintain this position throughout the entire movement.
• Retract your shoulder blades by squeezing them together. Press back up by separating the shoulder blades and rounding in the upper back, making sure not to move the lower body. This creates a "plus" movement at the height of your push-up without ever bending the elbow.

Pro tip: You can also do this on the forearms to incorporate the shoulders more, as energy is being dispersed through two joints instead of one.

Elbow Plank

• Start on your forearms with elbows under your shoulders. Maintain a plumb line, aka a straight line, from the shoulder to the hip to the ankle.
• Start with 10-second holds and build from there, adding 5-10 seconds.

L-Handstand or Wall Handstand

For the L-handstand, grab a chair:

• Place the feet on the chair and the hands narrow on the ground with your arms next to the ears, so your whole body is inverted as if to complete a handstand.
• Walk hands back until your body forms an "L." Squeeze your shoulder blades, and try to get your head through your arms.

For a wall handstand:

• Walk your feet up the wall as you walk your hands back toward the wall, so your body is inverted for a supported handstand. Go as far as you can safely.

• Squeeze your shoulder blades with your head through your arms, shoulders toward your ears and pelvis tucked.

• Start with 10-second holds and build from there, adding 5-10 seconds.

Superhuman

• Lie on your belly with your arms out in front of you and your legs stretched out behind you.
• Squeeze your butt first, and then lift your upper body to get your chest off the ground, keeping your ears in line with your arms without looking up.
• Lift your lower body as well to get your quads off the ground without bending the knees.

Reps:

With bodyfweight exercises (excluding the plank and headstands), Rivera says it's important to do as many reps as you can while keeping good form. She suggests once it starts to feel difficult, do five more reps. Complete three to four rounds.

In addition to these moves, Rivera emphasized the importance of mobility and flexibility to help build up my strength.

"Strengthening the back and shoulders requires you to be mobile in your joints and flexible in your anterior," she said. "Work on stretching the front of your body and the mobility of the shoulder, while you work on strengthening the shoulders and back." She added that awareness, mobility, and flexibility are key for achieving these toning and strengthening goals.