Can exercise make your breasts look bigger and perkier?

According to Kourtney Kardashian’s acclaimed fitness experts, it’s absolutely possible.

A recent workout tutorial posted on the 44-year-old reality star’s wellness website, Poosh, featured a Los Angeles-based Pilates instructor demonstrating how this works.

The six and a half minutes videoperformed by Shannon Nadj, who runs the Los Angeles-based Hot Pilates studio, showed an exercise routine that emphasized strengthening the pectoral muscles of the chest to give the appearance of perkier breasts.

Kardashian has said of her workout routine in the past, “We keep it simple with short rotations and no equipment required (just your body weight for some of the moves).”

Kardashian-approved Pilates instructor Shannon Nadj detailed a series of chest and shoulder strengthening exercises that can help breasts look perkier as the muscles strengthen.

Ms. Nadj, founder of the Los Angeles-based Hot Pilates studio, saying: ‘Unfortunately, you can’t push yourself to have bigger, perkier breasts. However, you can strengthen the pectoral muscles just behind and around this area.’

The pectoralis major muscle runs from the breastbone up and toward the arms and neck, while the pectoralis minor is below the main muscles and helps connect the ribs to the shoulder blades.

Breasts are not muscles and therefore cannot be toned in a similar way to glutes and abs. They are made up of different types of glandular and fatty tissue, so exercises to improve their appearance target large nearby muscle groups.

Dr. Alyssa Dweck, an obstetrician and gynecologist based in New York, said Good + Good: ‘There are no exercises for the breasts per se, particularly the internal glandular tissue, but typical pectoral muscle exercises can help.

“Doing these (exercises) can build enough muscle (to) make your breasts a little perkier.”

Fitness experts also agree that maintaining good posture can help strengthen your abdominal and back muscles, resulting in perkier and perhaps larger-looking breasts.

Unlike surgery to reverse the ravages of gravity or increase cup size, these exercises are not a quick fix.

Cat Kom, trainer and founder of Studio SWEAT onDemand, saying: “You can do exercises to stimulate your breasts, but you would have to do quite a few to see results.”

Ms Nadj’s moves emphasized opening her shoulders and chest while keeping her core abdominal muscles working and engaged.

While demonstrating a half-plank position in which the knees and the front of the calves were against the yoga mat, Ms. Nadj said, “You’re not hunched over, your shoulders aren’t curved forward.”

Throughout the routine, Ms. Nadj wore one-pound weight bracelets on her wrists, although she stated that you don’t need to wear weights to feel the impact of the workouts.

For another exercise to strengthen his chest and core, he assumed a prone, Superman-like position, face down, with his arms and legs extended in opposite directions. The goal of the exercise was to keep his legs and chest raised while he swam and kicked.

He also demonstrated standing shoulder presses and a rowing movement with his elbows open, his belly elongated as if zipped, while his shoulders remained down and relaxed.

Each movement required about 10 repetitions with short pauses before release.

In addition to highlighting key exercises to strengthen chest muscles for perkier breasts, Ms. Nadj demonstrated the proper way to stretch and lengthen the torso, including the pectoral muscles.

After the exercises, he stood tall, shoulders back and down, chest lifted, and arm raised toward the sky.

One at a time, he lowered each arm while keeping the other raised and high. As she inhaled, she raised both arms. As he exhaled, he let his right arm fall to his side while the left remained raised. Then he stretched the left side of his torso, waist and pectoral muscles.

She repeated that on the other side.

It is important to work the chest from multiple angles, although it may not be necessary to use weights. Mrs. Nadj, for example, wore bracelet-shaped weights, but she also made it clear that no additional equipment was necessary to feel the benefits of the exercises.

Still, some personal trainers maintain that working with enough weight is necessary to increase strength, and that working with heavy enough weights is important.

Jen Comas Keck, certified personal trainer, said Women’s health magazine that you should feel like you can do about two more reps at the end of each set, but no more: “It’s important to challenge yourself with heavier weights so muscle growth can occur.”