(dpa)- New mothers often find that their body feels different after the birth of their child. They feel weaker than before. Their backs ache from carrying the baby. It may take months to get back to lithe and lovely.

When the time comes to hit the gym or start an exercise programme again, new mothers must first check out what their body can handle. 

Classes geared specifically to mothers are becoming common. There are even outdoor workouts where the moms can bring the baby buggy, as well as fitness bootcamps at popular vacation spots. 

"Our motto is ‘Happy mom, happy kid,’" says fitness trainer Katja Ohly-Nauber, the founder of Laufmamalauf, a commercial organization which administers exercise classes to new mothers. 

Its classic option is an outdoor circuit training class, where mothers do full body training at the different stations and can have their babies near them in prams.

A special focus is on the pelvic floor, which weakens during childbirth. It is very important to restrengthen those muscles. 

"This includes supporting the back, correct posture and building muscles in the leg, said Petra Schweers, a midwife in Berlin.

Schweers instructs Kanga Training, a postnatal workout where the baby is close to the mother’s body. 

"At the same time it is important to take it easy on the pelvic floor. Leaping and jumping are taboo, so regular gym fitness classes are often poorly suited," she notes.

Once a woman engages in exercises again, it is important that she listens to her body and assesses her own well-being as she goes.

Schweers recommends women forget aiming to look like a fashion model again after eight weeks of training. 

Most women must train for longer periods of time to reach their desired figure.

Childbirth does not mean all contact with the midwife and gynaecologist can cease. These professionaly remain the experts afterwards in advising a woman what her particular body can stand.

In general, there is no set answer as to the extent and type of activity a mother should engage in after the child is born. Every woman's pelvic floor and abdominal muscles is different, meaning they will strengthen at different speeds.

Schweers and Ohly-Nauber both recommend a holiday from exercise for six to ten weeks - provided there were no complications during child birth. But a final examination by a gynaecologist should be done before beginning an exercise regime.

"From a purely physiological perspective, women should begin breathing and tension exercises while still in the hospital," physiotherapist Stephanie Wheeldon says. 

"Women are often insecure after receiving different advice from a variety of perspectives," she said. In many cases this causes women to start the right courses too late. 

"Women who were active during pregnancy have it easier," psychologist Marion Sulprizio says. "But you shouldn’t over-do it," she warns.

Ambitious athletes are often disappointed to find they cannot return to their previous level until six to nine months have passed. 

However, this interval is very important for the body to recover. Otherwise there is the risk of permanent problems, like incontinence. That makes it all the more important for moms to participate in guided activities to ensure no damage is accidentally done.