Former 'American Idol' singer says she didn't want to not be toned in front of her boyfriend.
Kelly Clarkson's boyfriend has inspired her to get fit.
The original 'American Idol' winner - who recently revealed she was dating the son of her manager for five years, Brandon Blackstock - has admitted that her romance makes her want to look better.
She said about her tauter figure: ''I would love to say that it had something to do with my work, but it doesn't.
''I have a boyfriend, and if I'm being completely honest, no one likes to be not toned when you are dating someone.''
The 30-year-old - whose new singing competition 'Duets' premieres in the United States on Thursday (24.05.12), told reporters during a press conference that she has lost weight after increasing her workout routine and by restricting her diet.
She added: ''I'm eating better and working out, but I've always fluctuated within 20 lbs. My whole life I've been like that.''
Sharing a trainer with her talent manager partner, 35, offers more of an incentive she shared.
Kelly said: ''I tone whenever I want, and I chose to now because my boyfriend and I are both really into it. But we don't work out together.
''We did that once and I didn't like huffing and puffing. I didn't like looking all red and gross, so I don't do that.''
Instead the pair find other activities to do together.
She continued: ''We both love music so we go to shows together. I am just more active with him.''