FF LOS ANGELES - Jennifer Lopez is in the ‘’best shape of her life.’’

The 49-year-old singer made a promise to herself that she would workout every day to make sure she was fit enough for her 15-show run and, although there were times when she felt physically and mentally exhausted, she feels like ‘’Superwoman’’ now because she’s so ‘’strong, happy and grateful.’’

Taking to her Instagram account, the ‘Get Right’ hitmaker posted a photo of herself standing against a white door in a tight-fitting bold red dress, showing off her muscular physique, and accompanied it with the caption: ‘’Feeling like superwoman after the show tonight!

‘’When I started this run I thought omg 15 shows in 27 days that’s a lot... but I made a promise to myself that instead of letting it wear me down I would be even stronger at the end of it...I will work out and be in the best shape of my life.

‘’There were moments I was tired and there was travel and I had to fit in my workouts where I could... but here we are with only 3 shows left!! And I am having so many emotions but mostly just feeling strong, happy and grateful!!! ‘’

Jennifer isn’t the only one surprised by her physical ability as her boyfriend Alex Rodriguez - whom she’s been dating for almost two years - has been training with her occasionally and is inspired by how athletic she is.

The 43-year-old former professional baseball shortstop said recently: ‘’Jennifer is an incredible athlete. She’s a former star athlete going back to junior high [and] high school. And we both just love the fitness space, we like to work out. We work out together, we workout apart. Yeah, she’s great.’’