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More Core in the Pool

A few years ago, a gym-based personal trainer told me that one of his client’s core had become notably stronger after incorporating just two days a week of Pool Aerobics with Kim into her schedule.

I was intrigued! This client is very active and pushes herself in every aspect. She’s also great at ensuring she nutrifies her body well for her fitness goals.

So, I was excited to start doing some research to identify what exactly made her core so much stronger in the pool?

First, let's start with the basics.

What is your core?

If you ask the average person this question they’re very likely to point to their stomach, your stomach or refer to the abdominal muscles.

Abdominals: These muscles of the anterolateral walls of the stomach are composed of three flat muscular sheets, the external oblique, internal oblique, and transverse abdominis. The obliques are located along the sides of the body and play a role in spinal protection and rotation. The traverse abdominis is involved in movement and spine stabilization. These three muscles are supplemented in front on each side of the midline by rectus abdominis. This is the muscle most persons associate with a six-pack. It helps stabilize the internal organs. These stomach muscles are a part of it however, there’s lots more.

Your core is the central part of your body. It not only includes your stomach muscles, but also your back muscles, glutes, hip flexors, pelvic floor and diaphragm.

Back: The quadratus lumborum is in the lower back. It extends from the lower rib to the top of the pelvis and is associated with back pain, posture, and mobility issues.

The erector spinae and multifidus muscles are back muscles which run vertically along the spine and enable flexion, extension, and rotation.

Glutes: The glutes are group of three muscles in your backside that influence hip rotation and extension.

Pelvic Floor: The pelvic floor houses internal organs and includes connective tissues such as hamstrings, hip flexors and abductors. Together the pelvic floor muscles and tissues are associated with hip stabilization.

Diaphragm: The diaphragm contracts and flattens during inhalation and exhalation.

The core is the center of our body, and it functions to stabilize the trunk, shoulders, and hips, while the arms and legs move during functional movements. A strong core spares the spine from excessive load and transfer force from the lower body to the upper body and vice versa.

Why do we aim for a strong core?

If you ask the average person why we work on our core, they will say because they want lean stomach and six-pack abs! Having visible abs means that you have low enough body fat to make the muscles defined. Those who are physically strong may have more pronounced abdominal muscles, however where your body stores most of its fat is largely up to genetics and hormones. Someone with a strong core may not have visible abdominal muscles. But what was mind-blowing to me is that someone with a visible six-pack may not have a strong core.

Having a strong, stable core helps us to prevent injuries and allows us to perform at our best. It’s a key factor for your bodily balance, performance during workouts and mobility.

Let’s dig deeper into the benefits.

Injury Prevention: Most injuries happen during performing everyday tasks like taking out the trash, lifting kids or reaching into the bottom drawer to get out that pot you rarely use. Maintaining a strong core can help you avoid all types of injuries, including muscle strains, joint sprains, disk protrusions, and even fractured or bruised bones.

Reduces Back Pain: Having strong core muscles creates a system of support for your spine. According to a recent study by PubMed Central, 50% percent of adults in the United States live with chronic back pain. Although there are many causes of back pain, researchers know that there is a correlation between weakened core muscles, mobility issues, and back pain intensity.

Improved Balance and Stability: Having good balance and stability is essential in everyday life. Walking down a set of stairs or getting dressed, a strong, stable core reduces the likelihood of a fall. While aging and managing health conditions such as arthritis, a fall can be detrimental. Regular core strengthening exercises improve balance, independence, and quality of life in older adults.

Improved Posture: Many people unconsciously have poor posture from looking down at their phones or computers. This can lead to neck, shoulder, back, and other musculoskeletal disorders. Strengthening the core muscles improves posture by maintaining the spine’s natural curvature and pelvis’ neutral alignment. With a strong core, less strain placed on supporting structures like muscles, ligaments, and disks.

Athletic Performance: Your core is the power house of your movements and core strength allows the pelvis, hips, and lower back to work together more smoothly with less rocking and less excess energy expended. This results in improved legs and upper body synchronization, better running form, more power swinging a tennis racket or baseball bat, throwing a punch and the ability to lift more weight.

Why is core so much more in the pool?

There has been a strong movement away from traditional core exercises – sit-ups, crunches, side bends, etc. New research on the effectiveness and safety of these exercises shows that they may do more harm than good.

Health professionals have shifted to more functional exercises to enhance the stability of the hips, torso, and shoulders. The pool is becoming a go-to for core strengthening.

Here’s why!

  1. In the pool, you engage your core almost straight throughout class. This is because the water moves around your body, trying to move your body and your core muscles work to stabilize and support your torso. This is just core work from static positioning.

  2. Core exercises which include movement is movement against resistance, in every direction. With the natural density of water and add the water flows in different directions when you’re doing movements in a pool with other participants, the water resistance can be anywhere between 4 to 42 times greater than air. That is, your core muscles work much harder moving against the water than against air.

  3. Being in the water makes you feel weightless, allowing you to move more freely and easily. Participants feel more comfortable fully lengthening then contracting, stabilizing, and rotating to their maximum potential, despite feeling some muscle fatigue because they feel safe and supported in the water. They are also not feeling the pressure of their body weight on their body but still enjoying the core muscle burn.

Pool Aerobics with Kim and Core Work

The biggest challenge I have with teaching core work is helping my clients learn how to engage their core. When I just started coaching there were a lot of tips about holding your hand on your lower stomach, however most can’t relate. Instead, I vary my verbal cues to keep everyone core aware.

A few cues I love are:

  • No hands-on-waists! Use your tummy to try to gain stability.

  • Exhale as you bring the belly button to the spine.

  • Try to make an SSSSSSS sound while you brace your tummy for a punch!

I encourage them to try practicing these things while sitting in traffic, standing in the line at the bank or even during their supermarket shopping.

My group class participants have quite a laugh when they see each other running errands or at an event and remind each other to engage their core. I also remind my participants about the importance of nutrition.

In Jamaica the fitness community is pretty knowledgeable on the building blocks of muscles however the average Jamaican does not recognise that eating right is an essential part of building a core that is healthy and strong. I encourage them to discuss their goals with a nutritionist and implement the advice received as best as they can.

A stable core is important for preventing injuries and for enhancing performance in sports and everyday life. Getting your core work done in the pool is very effective, safe and a tonne of fun.


Kim Nesbeth is an aquatic exercise instructor certified with the Aquatic Exercise Association, a S'WET™ Instructor, Aqua Zumba® Instructor and Certified Lifeguard. She is also the founder of Pool Aerobics with Kim, a great low or no impact exercise option. The intensity is easily modified to your ability while achieving your goals. Classes focus on aerobic endurance, resistance and strength training. Exercising in water also improves balance and gait, mobilizes joints and stretches muscles in an enjoyable atmosphere with music.

Find out more about Kim's services and specialties on her website:

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Ronnie Miller
Ronnie Miller
Mar 06, 2023

Great job!

Aug 04, 2023
Replying to




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