Vanessa Hudgens: Relationship with Efron kept me grounded

US actress Vanessa Hudgens has revealed that her relationship with ex-boyfriend Zac Efron helped to keep her grounded.

Speaking to Shape magazine, the 22-year-old High School Musical star revealed that the pair split due to their busy schedules.

"Long-distance relationships are hard no matter what. When you don't have face-to-face time, it's just different. Having an iPhone helped, but it wasn't the same," Hudgens said.

"The relationship kept me grounded and because I was with someone who knew me so well, I didn't need to try to be someone that I'm not."

Hudgens is currently promoting the film Sucker Punch, which she starred in alongside Emily Browning and Abbie Cornish.

The actress revealed that she had to put in plenty of physical training to prepare for the role, including lifting weights.

"In the beginning I could dead lift 135lbs. By the end, I lifted 180lbs. I was a monster," she added.

The action-fantasy film sees Hudgens escape with a gang of girls from a mental institution.