. >> reporter: hollywood trainer, jeannette jenkins, knows. >> the hollywood trainer. >> reporter: training some of the hottest bods in hollywood. >> i train pink. i train alicia keyes. i train kelly roland. >> reporter: pushing her "a" >> we hit everything. we do cardio. we do sculpting. we kind of take everything up a level. >> reach for those arms make them straight. >> reporter: in the three to six weeks leading up to the red carpet, her celeb clients working out every day for an average of two hours. >> most of the time the women are in gowns and their arms are open. i make sure i hit those arms and the upper body. like there exercise targeting the arms and upper back. >> alternate. jeannette says the row and fly is a celeb favorite and it works. >> does pink do this? >> she sure does. she does whatever i tell her! no, i'm just kidding. >> reporter: another secret, nutrition. >> lowering the sugar content. so it's like no more processed foods. no sugars. >> reporter: but her best advice beyond hitting the gym, confidence. >> my number one thing is absolutely never know self-hate. you h

. >> reporter: hollywood trainer jeannette jenkins knows. >> the hollywood trainer. >> reporter: training some of the hottest bods in hollywood. >> i train pink. i train alicia keyes. i train kelly roland. >> reporter: pushing her "a" list clientele to tone up fast. >> we do cardio, sculpting and >> reach for those arms make them straight. >> reporter: in the three to six weeks leading up to the red carpet, her celeb clients working out every day for an average of two hours. >> most of the time the women are in gowns and their arms are open. i make sure i hit those arms and the upper body. like there exercise targeting the arms and upper back. >> alternate. jeannette says the row and fly is a celeb favorite and it works. >> does pink do this? shoo she sure does. she does whatever i tell her. i'm just kidding. >> reporter: another secret, nutrition. lowering the sugar content. so it's like no more processed foods. no sugars. >> reporter: but her best advice beyond hitting the gym, confidence. >> my number one thing is absolutely never know self-hate. you have to absolutely love yourself. >

trainer jeannette jenkins knows. >> the hollywood trainer. the hottest bodies in hollywood. >> i train pink, kelly rowland. >> reporter: pushing her a-list clientele to tone up fast. >> we do everything, we do cardio and sculpting. then we take everything up a level. >> reporter: in the three to six weeks leading up to the red carpet, her celeb clients working every day for an average of two hours. >> i make sure that i hit those arms and the upper body. >> rotate. reach. >> reporter: like this exercise targeting the arms and upper back. >> alternate. row. fly. >> reporter: jeannette said the row and fly is a celeb favorite and that it works. >> does pink do this? >> she sure does. she does whatever i tell her. >> reporter: another secret -- nutrition. >> lowering the sugar content. so it's like no more processed foods. no sugar areas. >> reporter: but her best advice confidence. >> number one thing is, absolutely no self-hate. you have to absolutely love yourself. >> reporter: for "good morning america," abbie boudreau, abc news, los angeles