Fran Halsall insists her disappointing performance in the 100 metres freestyle at the World Championships will stand her in good stead for London 2012.

Halsall was the fastest qualifier for the final, securing her a coveted middle lane, but could only manage fourth place at the event in Shanghai in July.

But far from being a chastening experience, the 21-year-old believes it has provided in invaluable lesson ahead of next year's Olympic Games.

Halsall, who is targeting the 50m and 100m freestyle and 100m butterfly at the British trials in March, now has the belief that she can strike gold in London.

"Shanghai was a weird one because before I went I didn't expect to be in the position I found myself in when I got there," she said.

"I didn't expect to be in lane four, being the fastest qualifier for the 100m freestyle final, because I didn't think I'd done the training to put myself in that position.

"My mind couldn't get to grips with what was happening. It was a mental and physical thing.

"Also, I hadn't done three 100m freestyle races in a row that fast all year.

"Once I'd got to grips with what happened in Shanghai I looked back over the swims and understood what I need to improve on.

"I also gained a lot of confidence knowing that there are two girls in world faster than me by four 100ths of a second, yet due to injury I'd only done half the training I was supposed to do last year.

"It's hard standing behind the blocks knowing you haven't done as much training as everyone else has, it niggles at you slightly and it affected me.

"These thing happen and I learned from it. If I end up in lane four in the Olympic final, it will be a breeze.

"I can only take great confidence from that. This year I'll do everything I can to be as ready as possible for the Olympics.

"Whatever happens then happens, but I'll leave no stone unturned in preparation."