Miranda Kerr has been working out for the past six months to get in shape for the upcoming Victoria's Secret Fashion show.

The stunning model - who gave birth to son Flynn in January - admits she's been exercising hard so she is in her best shape for the prestigious annual show, which takes place next month.

Miranda - has been chosen to wear this year's $2.5 million 'Fantasy Bra' - told fashionista.com: "This is something I've always wanted to do. I do yoga. That's something I consistently do as well as Pilates. So I've been doing that for the past six months. But I've been doing more squats because you gotta get that booty up - you really can't hide anything when you're up there on that runway - you've got cameras coming at you from every angle."

The bra has 3,400 gems hand-stitched into the it and took more than 500 hours to make. The piece of lingerie contains diamonds, pearls, citrines and aquamarines and a tassel centrepiece comprised of two 8-carat white diamonds and two yellow 14-carat diamonds.

The 28-year-old beauty said after being chosen: "It's such an honour to wear the bra! And it's such a piece of artwork! It's absolutely stunning - it kind of feels a little mermaid-like - but I can't believe I'm wearing $2.5 million on my chest."