Shoko Nakamura embarked on a challenging journey when she began retraining for ballet performances just one month after giving birth to her son, Joel, in 2011. The dancer, who goes by just her first name when performing, says the physical pain involved in getting back into shape often reduced her to tears.

"All the muscles I had built up over the previous 20 years or so had gone," says the 35-year-old Shoko, who at the time of her son's birth was a principal dancer at the renowned Berlin State Ballet. "That was the most devastating thing for me, I had to restart from scratch."

As trying as the experience was, it was not the first serious obstacle that she had had to overcome. At 19 she suffered a serious ligament tear that took 18 months to fully recover from. Postpartum recovery, however, posed a different type of challenge.