Adlington added the 800m freestyle to her 400m victory earlier in the week at the British Gas Swimming Championships, meaning she will defend both her Beijing titles at London 2012.
Over both distances she now boasts world-leading times but there are plenty of international rivals who have her in their sights, notably world champion Federica Pellegrini over eight lengths and Denmark's European champion Lotte Friis in the longer distance.
However, domestically Adlington has no peers, although teenager Eleanor Faulkner, who grabbed the second Olympic qualifying slot, is a swimmer whose star is on the rise.
"It's excruciating when you get out on your own," said Adlington, after a race, won by a 20 metre margin, that was only really with the clock.
"It’s so painful. I wanted to keep pushing myself to try to get a good time but I had no idea how quickly I was going.
"I’m very pleased with that time. Athletes are always trying to find ways to improve and I’ve been on the same time for a couple years so it’s good to be improving.”
Adlington believes another five months hard work, under the guidance of coach Bill Furniss, should put her in a position to go even faster when she returns to the Olympic Aquatic Centre this summer.
She rewrote one of her sport's oldest record she won clocked 8:14.10 in Beijing and her winning time last night was 8:18.54, a solid early-season marker that should give cause for confidence.
"I’ll sit down this weekend to see what I’m going to do next. I’m sure Bill has an idea and I know it’s going to hurt," she added.
"I don’t know if I can break my world record but I know I can keep improving. I’d love to get down there again, especially at the Olympics. I did it four years ago so I don’t think it’s an impossible target.
"However, the past four years have been more about the race than the time, where you come at the Olympics is much more important."
European champion Simmonds is fastest in the world over 200m backstroke this year and clocked 2:08.67 to win a seventh national title at the British Gas Swimming Championships in London.
Franklin, still just 16, is expected to be one of the stars of the Games after winning five medals, included three golds, at last year's World Championships.
She will start red-hot favourite in Simmonds's signature event but the 21-year old is not overawed as she prepares for a second Olympic appearance and improving her sixth place finish in Beijing.
"I can breathe a sigh of relief now but leaving qualification to the last race is pretty tough on the nerves," said Simmonds.
"I was so stressed I didn't sleep very well but chilled out before the race, I tried to relax and think calming thoughts.
"The pressure of this week has been huge but I tried to have a laugh and giggle before the race to calm me down.
"The stands, the crowds, the atmosphere is very different. It doesn't feel like a British Championships it feels like a major meet. I can't wait to come back here and being ready to go in the summer."
Simmonds believes there could also be a benefit from having a light racing schedule - with just one event entered - at the Games.
In contrast to Franklin, who will be in and out of the pool with an expected whirlwind of races, Simmonds has just one shot at a medal.
"It wasn't a perfect race and there is still a lot to be done. I'm looking forward to getting back training hard now," she added.
"I took it out like I would like to in the future and hopefully I can bring it back better, it definitely hurt towards the end.
"There was a little bit of energy gone from just being stressed this week and that won't happen at the Olympics - I can race hard with the pressure off and I've got one race to focus on."
The British record holder has endured a difficult week as he was overhauled on the final length of the 200m fly to lose not only his title but also an Olympic spot in his preferred event.
But he made sure that he would not be denied a place on the British team as he recorded a textile best 52.02 to win the 100m fly ahead of rising star Jack Marriott.
And Rock admits he had breathed a huge sigh of relief after ensuring that four years’ hard work would not be in vain.
“It had been a disappointing couple of days with the 200, but the 100m was a great opportunity for me to regain my focus and I had a wonderful opportunity to make the team which is what I’ve been striving after for the best part of my career,” said Rock.
“There was extra pressure on because I didn’t take the opportunity in the 200. But pressure can be great, it can help you get focussed and fortunately I’ve managed to do that.
“It’s the best time since the suits, so I can have great belief that I can get a bit more out of myself for the summer.”