Sotherton has a personal best of 40.81 metres in the javelin

The Olympic bronze medallist slid from second to seventh at last summer's Europeans after a poor throw.

"I'm not pretending I am going to throw far, but I am on the road to improvement," said Sotherton, 30.

"I've learned a lot, previously I was scared but now I want to get up and throw it. I've started to enjoy it."

Sotherton has gone through a raft of javelin coaches, amongst them John Thrower, former British international Mick Hill and now Mike McNeil.

However, the Commonwealth champion insists that the improvements McNeil, the former coach of British javelin number one Goldie Sayers, and herself are making are geared towards the 2008 Beijing Olympics.

"I have made a change during the season which is quite drastic but my bigger picture is next year," said Sotherton.

"I needed to change and cut my losses because I wasn't going to get any worse.

There is a little bit of pressure on me now and the standard is very high British heptathlon number one Jessica Ennis

"I think a lot of people think I don't work on my javelin and I just turn up and throw. I'm trying really hard and I go through a lot of turmoil to try."

Sotherton goes into the Worlds in Osaka ranked as the world number 12 while British number one Jessica Ennis is third in the world behind Ukraine's Lyudmila Blonska and Swedish defending champion Carolina Kluft.

Both British heptathletes carry strong chances of winning an individual medal for the team in Japan.

However, despite making great strides this season, Ennis, 21, is playing down her chances of picking up a medal in Japan.

"There is a little bit of pressure on me now," said Ennis, who took Commonwealth bronze behind Sotherton in Melbourne.

"The rest of the girls are competing well and the standard is very high.

Ennis improved her personal best to 6399 points this summer

"I think it is going to take 6600 points to take a medal and that will mean I have to add 200 (to my personal best) which is a lot to ask.

"But if I can score a PB and have a good day it is possible. I've had a brilliant season so far and everything is going to plan."

Ennis, who has recorded personal bests this season in the 100m hurdles, 800m, long jump, shot put and javelin, is worried that the climate might play a part in deciding the medals.

The Sheffield athlete is currently acclimatising with the rest of the British team in Macau this week.

"The humidity is new to me and it is quite tough, but I am slowly getting used to it," said Ennis.

"We know it is going to be hot and humid so we are hoping there is going to be a lot of shade on the track."