By Barbara Goldberg NORWALK, Conn. (Reuters) – Still shunning alcohol because she was breastfeeding her 7-week-old baby, Jessica Hopkins grabbed a 50-pound (23 kg) beer keg with her bare hands and hurled it over a chest-high metal bar. Women like Hopkins, a former jewelry design assistant, are the fastest-growing group of competitors in Strongman, a sport that involves chucking, dragging and hefting tremendously heavy weights. “It’s almost like labor – you have to work through it even though it’s hard,” Hopkins said recently on her first day back at Strongman training since giving birth.