When it comes to their abs after giving birth, many women could either give a rueful laugh - or cry. This is because the expanding womb during pregnancy commonly causes the rectus abdominis muscles, the two long muscles that run down the middle of the belly from chest to pelvis, to separate.
Called diastasis recti, this "ab gap" can make their belly bulge for a long time postpartum. The size of the gap between the muscles, which isn't painful, can easily be gauged with the fingers.
Here, a gynaecologist and physiotherapist explain when the condition becomes a problem, and how to prevent and manage it:
It's normal for a woman's abs to stretch and separate as the foetus grows and takes up more space. "In addition, hormonal processes are set in motion during pregnancy that promote stretching of connective tissue," says Dr Klaus Doubek, president of Germany's Professional Association of Gynaecologists (BVF).
As the uterus enlarges, the elastic band of connective tissue between the rectus abdominis muscles, called the linea alba, pulls apart and thins. It doesn't retract immediately after birth of the baby, and sometimes not as much as it should. An abdominal gap wider than 2 centimetres is diagnosed as diastasis recti.
The width of the gap depends on various factors, including the size of the mother and baby, whether it was a multiple birth and how well conditioned the abdominal muscles are. Sometimes the gap is visible as a hollow space along the midline of the abdomen, or a bulge just above or below the navel when the abs are contracted.
If diastasis recti is minor, there's generally no problem and the gap will close by itself in the months following childbirth. "Many women still have a mild case of diastasis recti a year after delivery though," Doubek says, but "usually there's no medical reason for an operation."
Pronounced cases can lead to an epigastric or umbilical hernia, a weakness or opening in the abdominal wall that typically gets larger over time and through which fatty tissue or part of the intestine may protrude and become trapped. This can cut off their blood supply, causing tissue death and a medical emergency.
Hernias should therefore be surgically repaired.
Expectant mothers can help keep diastasis recti to a minimum with strong abdominal muscles. "It's important to do something while still pregnant," says Ulla Henscher, a member of the German Physiotherapy Association's (ZVK) working group on gynaecology, obstetrics, urology and proctology.
If the pregnancy is without complications, they should get in 150 minutes of exercise per week, including both aerobic and tailored strength training, according to Henscher. "Many women go too easy on themselves," she says. "But it's important to prepare physically, too, for the birth and the time afterwards."
She dismisses the widespread belief that diastasis recti can be closed by training the oblique abdominal muscles, located on the sides of the trunk. "This was the thinking for decades, although it has never been studied," she says.
Instead, she advises that women, during pregnancy and after giving birth, strengthen their rectus abdominis muscles with tailored exercises. By tailored, she means exercises that are apposite and done with an intensity that's attuned to their body.
It should be hypertrophy training, she explains, which focuses on increasing the size of muscle fibres. As the intensity of training increases, muscles get stronger. This is important both during pregnancy and postpartum, of course, because the baby keeps getting heavier, and Mum usually carries him or her around a lot.
Exercises on all fours are well suited for this, Henscher says, since "you work your abdominal muscles even in the basic position." To work them harder, you simply lift a knee or stretch out an arm and/or leg.
Planks are beneficial as well. In the straight-arm plank, you support yourself on your hands and toes, with your arms and legs extended and body in a straight line from head to heel. An easier plank variation is supporting yourself on your forearms and knees, keeping your back straight.
Another good exercise, Henscher says, is sitting upright on the floor and tilting your upper body backwards. "There's not one single exercise you do the whole time - it's always got to be strenuous," she remarks.
After childbirth, women can quickly begin with simple exercises such as deep breathing in the therapeutic prone position. Pillows placed under the belly ease pressure on the lower back, and no pressure is put on the chest.
"After a natural birth, you needn't wait three months before starting postnatal classes with tailored exercises," says Henscher, and planks along with exercises in the all-fours position are well suited for this. It's important, she adds, that the classes be led by a specialized midwife or physiotherapist.
