They spent four weeks training at altitude in Flagstaff, Arizona, and then three weeks in California, where she trained with Powell.
The benefits were instant. In April, Ririnui jumped 6.36m to smash her own personal best mark at the Messa Classic in Phoenix.
Not only did that win the event but, more importantly, qualified her for the World University Games.
She then spent time working with Powell.
"I met him when he was in Wellington for the nationals and he invited me to train with him. Everything just kind of fell into place," Ririnui said.
"I had some training sessions with him and he watched me compete. The biggest learning points with Mike were about the mechanics of long jump.
"It is a really technical event. He broke it down for me about angles of your levers and your body angle at take-off.
"It was very specific to long jumping and I had never learned about that so much before. It was great and I learned a lot. I jumped really well and he gave me a lot of confidence.
"He told me the Olympics were definitely achievable for me and he is willing to help me a lot more now.
"He wants me to spend about six weeks training with him to learn everything he has to offer."
To qualify for next year's Olympics in Rio, Ririnui will need to break the New Zealand record of 6.68m held by Chantal Brunner since 1997.
"That is definitely my goal," Ririnui said.
"To qualify for world champs and Olympics you have to jump 6.70m so that will have to be knocked off anyway in the process of qualifying."
- To help fund her trip to South Korea, a Givealittle account has been set up for Mariah at givealittle.co.nz/cause/mariahririnui.
