The pair have been training side-by-side in the pool for almost a year after Boyle joined the Miami club at the end of 2014, having been hampered by a period of long-running instability at the top of Swimming New Zealand's elite programme.
At the time, Coleman was the only senior female in Miami's programme, which is headed by celebrated Australian coach Denis Cotterell, and was relieved to have another woman join the team.
"It's such a doghouse, there's so many boys," jokes Coleman.
"I was so happy when Lauren joined the programme. It's so much more fun. But also having someone to pace with and swim against was really helpful."
A few months after Boyle linked up with Cotterell, another Kiwi swimmer, 2012 Olympian Matt Stanley, also joined the Miami programme. Cotterell, who coached two-time Olympic champion Grant Hackett, is known as a bit of a mad scientist of the swimming world and a tough task master.
Swimmers from all over the world head to the Gold Coast to train under him - a development that hasn't always gone down well with Swimming Australia officials.
My dad thinks it's so great that I train with Lauren and he's really excited that I get to be part of the Kiwi team for a week.
"Denis has coached a lot of foreigners over his career. He will coach any swimmer that is prepared to work hard. He wants to be able to coach whoever he likes," Boyle said.
"We all come from different environments to the Aussies and sometimes you can tell that we don't get the same level of support as they do and we've done it a little bit tough.
"And I think Denis likes for the Aussie swimmers to see that sometimes."
Boyle will return to the Gold Coast this weekend, where she will remain up until the national championships, which double as Olympic trials, in late March. With the 1500m freestyle - one of two events at which Boyle won silver at the world championships in August - not on the Olympic programme, the 28-year-old will focus on the 400m and 800m freestyle events.
While New Zealand's elite swimmers must hit the qualifying times for Rio at the national championships in Auckland to be selected for the Games, Coleman already has some security.
The Swedish national body has "pre-selected" the 24-year-old for the Games due to the country's impressive relay results at the world championships, but Coleman still needs to qualify for the individual events she wants to target.