Halsall completed the event with the gruelling prospect of four races in one day. In the morning she competed in the heats for the 50m butterfly before cruising through the semi-finals and going on to win the final in a time of 25.91 seconds.
And if that wasn’t enough for the 23-year-old, she also had the small matter of retaining the 100m freestyle crown she has held since 2009.
She did so in impressive fashion, cruising to a time of 54.82 seconds and cementing her place as one of Britain’s brightest medal prospects at next month’s World Championships.
“It was hard, I came in and I was a bit scared to do three swims in one night, I haven’t been working towards doing that much,” said Halsall, who came fourth in both the 50m and 100m freestyle events at the World Championships in Shanghai two years ago.
“For the worlds it’s a really good sign because I can back up two 50s in a night, it’s given me a great confidence boost.
“I know I can do it now, I can concentrate on swimming fast in Barcelona and another two weeks of hard work.
“I haven’t been working a lot of the 100, it’s a building process towards 2016, I’m trying out different tactics but the 50s are definitely working.
“In the 50 fly now I’m ranked fourth in the world and in the 50 free I’m ranked third, so I’ve been putting in consistent times this year so hopefully that will put me in good stead for Barcelona. I will be there or thereabouts.”
Another who has walked up to the top step of the podium three times this week in Sheffield is Jazmin Carlin - and after wins in the 800m and 1500m freestyle, she completed her championships with a victory over 400m.
"It has been such an incredible week for me and I have enjoyed it from start-to-finish," said Carlin, who missed out on last year's Olympics.
"I didn't set myself any targets before the week started - the aim was simply to qualify for the World Championships and I have achieved that in more than one event.
"The next step is just moving on, improving and keeping the momentum going for Barcelona - I really want to do well in Barcelona."
Elsewhere, three Scottish records were broken – Craig McNally clocked 1:56.36 on his way to gold in the 200m backstroke, Dan Wallace finished second to Roberto Pavoni in 4:15.22 minutes in the 400m medley while Robbie Renwick touched home in 49.17 seconds in the 100m freestyle but saw Adam Brown claim gold.