Fit before giving birth, Natalie Flood didn’t understand why her “mummy tummy” wouldn’t go away.

The Pilates instructor soon discovered the reason: her stomach muscles had weakened during pregnancy, and separated.

“Everyone is born with abdominal separation, but through developmental movement as babies, the space naturally closes,” said Ms Flood who had learnt all about it through her work. “During pregnancy a separation sometimes occurs to make room for the developing foetus. Abdominal separation often heals itself six to nine months post-partum.”

It’s not just a women’s issue. Some men are born with weak muscles, others develop them through working out incorrectly.

She discovered hers had separated last April, shortly after giving birth to her now one-year-old son, Leo. At eight weeks after pregnancy the norm would be 1½ to two finger lengths of separation; hers was four to five.

For some women, abdominal separation is connected to lower back pain or incontinence; the lack of support can also cause the pelvic organs to “fall” on to the vagina. The problem was largely cosmetic for Ms Flood who ignored advice from her general practitioner to see a physical therapist.

“I figured I was really fit, so it would be fine. It would just go away,” she said. “I knew there was a problem, but I figured, I’m a Pilates teacher; I know what I am doing. I can rehab this on my own.”

She jumped back into her work and, within a few weeks, discovered she was doing more harm than good.

“I had this panicked feeling,” she said. “I was doing all these things, Pilates, yoga, barre — so why weren’t these techniques bringing my abdominals back together?”

She made an appointment with physiotherapist Michelle Monk who explained that the condition was being aggravated by a problem that affected many women in the fitness industry — her pelvic floor was too tight.

“She was basically, like, this is what is happening and it is because you were not doing things correctly,” Ms Flood said. “We all tend to pull up, be thin and suck in our stomachs to look a certain way. Your pelvic floor ends up being very hypertonic. It’s like a muscle that is not lengthening or contracting. Your abdominal centre is not moving.”

Through chiropractor Mark Da Ponte she learnt that neutral spine, a Pilates technique she’d recommended for clients with abdominal separation, had exacerbated the problem.

The revelation caused her to research the right ways to tackle pelvic floor issues. She’s added them to her roster of Pilates, fusion and cardio classes at her studio, Shamana Circle.

“The pelvic floor is the space between the pubic bone and the tail bone. If you were to sit upright on a ball and cross your legs in front of you, all the space you’re resting on would be the muscles of the pelvic floor, uterine, bladder and rectum.”

Her own problem is largely gone now; her clients are happy with the change in Shamana’s focus.

“It is fixing everything from back and shoulder pain to reoccurring headaches,” she said. “I have girls who used to be on heavy pain medication who are now not taking any because this is serving them so well.”

• Shamana Circle offers yoga, Pilates, fusion and cardio classes for new moms, but also for men. For more information: www.shamanacirclestudio.com or 707-0273