Willis, who is based in the United States, has been training and competing in New Zealand for almost two months.
The 2006 Commonwealth Games 1500m gold medallist setup a mini training camp in Wellington with some of the best runners in the lower-North Island, before running the mile at the Cooks Classic in Wanganui last Tuesday, and the national 3000m in Wellington last Friday.
"It's been a lot of fun,'' Willis said. We did some really fantastic training together and I think the results of the Wanganui mile were evident.''
Willis was one of three runners to clock a sub 4min mile in Wanganui. He won in 3min 55.56sec, while training partners Hamish Carson (3min 56.72sec) and Eric Speakman (3min
57.30sec) were second and third.
The national 3000m record holder (7min 36.91sec) then romped to the national 3000m title in blustery conditions in Wellington.
Willis will not compete at the national track and field championships in Dunedin from March 4-6. His last race in New Zealand, before heading back to the United States to prepare for the world indoor championships in Portland at the end of March, is the Christchurch street mile on February 8.
Australian guns Ryan Gregson and Brett Robinson are crossing the ditch to race Willis.
Gregson is the Australian 1500m record holder and Robinson is the Australian 5000m and 10,000m champion.
While this year is mostly about the Olympics, Willis does have a couple of other goals.
Firstly, he wants to make up for being disqualified for stepping inside the track about 80m from the finish-line two years ago at the world indoor championships in Poland.
He also wants to break Sir John Walker's national mile record (3min 49.08sec), set in 1982.
Willis has a personal-best of 3min 49.83sec and believes he is capable of topping Walker.
"Hopefully I will get a good crack at it this year,'' he said. ``There might be an opportunity in June over in Europe to do that, as long as it fits into the overall plan.
"My personal-best over 1500m (3min 29.66sec) indicates I should be able to go under it if the right opportunity presents itself with the weather and the way the race is run.''
With less than seven months until Rio, Willis said he is healthy and ready to give it his all.
He has subtly increased his mileage the past three years, and has also stuck to a professional strength and conditioning plan for the first time in his career.
In the past, Willis felt his muscles fatigued heading into the third race of a five-day championship, but hoped the extra strength and conditioning work would rectify that.
"I have a really solid foundation under me,'' he said. "Nothing that necessary indicates I'm way ahead of any other year. But the main thing is I'm healthy and have had a really good solid amount of work done.
"You sort of just keep working towards the bigger goal, and only when that time comes do you know if you have reached that apex that you hope and dream of in training.''
