Shakira is said to have impressed Rihanna with her figure as they shot Can't Remember to Forget You.
The two singers collaborated for the track. For the music video both stars are seen frolicking about seductively and showing off their enviable figures.
As they filmed the video Shakira is said to have shared a valuable and effective work-out with the 25-year-old singer.
"Shakira introduced Rihanna to the butt push-ups when they were working together for Can't Remember to Forget You. Rihanna was amazed by how fit Shakira got after having her baby. She couldn't stop complementing her," a source told British magazine Look.
"[Rihanna's] whole body is changing. She's put on a good 5lb of muscle and lost fat. She's down from 25 per cent body fat to 21 per cent, which is really impressive. She was a [US] size 4 and now she's down to a 2."
Rihanna's long-time personal trainer Ary Nuñez has opened up about how she motivates the musician. She also revealed her advice on how to get a toned bottom just like Rihanna.
"Working with Rihanna is really a treat. She's so hard working but she gets bored. I gotta keep it fresh," Ary explained.
"My other top tips for getting the perfect butt are to dance, like Shakira does, and try martial art such as kung fu, which uses the entire body. It's all about losing the fat and building up muscle."
Shakira recently praised Rihanna and how much she enjoyed their time together. She too learnt something from the Bajan singer.
"She's the sexiest woman on the planet. And at the end of the day, we're both just basically Caribbean girls. The chemistry was so good and so real. She taught me dance moves. She was a sweet teacher," Shakira gushed to US Glamour magazine.
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