"The T42 was a great dose of heaven followed by a lot of hurt."
His goal was to raise more than $20,000 for Hospice, but the total pledged is now more than $42,000.
"By being a long challenge over a full year I am hoping for people to sponsor me per event and I will invoice them each month, making it easier on the pocket."
Tennent will run five to six events a month to allow for the quieter months of December and January, and every event will be an organised race.
There is a long way to go but he is up for the challenge.
He is well supported by his partner, Lorraine. The father of Kate, 15, and stepfather of Kelsie, 20, and Jamie, 25, said he wouldn't lack any motivation as he would run with his late mother in the back of his mind.
And his body is holding up so far. "I have a slight groin strain that I will nurse but Sunday's Xterra Riverhead race in the mud was awesome."
The sports-mad Tennent answered some questions from us about his non-stop running mission.
Q. What has inspired the 52 in 52 challenge this year?
Mainly what Hospice did for my Mum, but also what fantastic feats other runners have achieved for charity. People like Mal Laws, with his running all over New Zealand and last year in England, made me think: "What could I do that would make people sit up and take notice ... and dig into their wallets?" Also a touch of the "something to tell my grandkids about" - if I ever get any!
Q. Why have you chosen Hospice as your charity?
BNI - which I contract to - is one of Hospice's three national sponsors, so I became a lot more aware of Hospice through our involvement. However, it wasn't until my mother got a brain tumour that I really got to understand how wonderful they are.
They swung into gear with in-home help for her and when she got too much to handle at home she moved into Hospice for the last few days of her life. Last year I moved way out of my comfort zone in running the 60km Tarawera Ultra Marathon and raised $5100 for Hospice. This year I wanted to go one better.
Q. Have you done anything like this before?
Just the Tarawera Ultra last year. I had a few friends doing ultra-marathons and I said no way for me, however, the lure of doing it for Hospice made me enter and when I finished it was one of life's highlights, as well as being a very emotional moment.
Q. How much have you run before taking on this challenge?
I started running seven years ago to help lose some weight. I was 112kg, and caught the bug. Last year I ran 24 events, mainly trail runs and mainly half-marathons. I am in love with our land and the trails, and live to run them. The nice thing is that I never train - I love running the trails around Rotorua so much that every run is running for pleasure, not for training.
I had been averaging 50km per week in the lead up to the Challenge.
Q. What do you think will be the toughest part of getting this done?
The travel: I will drive up to 25,000km this year to and from events. There will also be a few weekends like this coming one where I have two events.
I have 24km up and down Rainbow Mountain twice as part of the Double Rainbow Trail Run on Saturday, and 21.1km on Sunday at Pukeora in the Hawkes Bay as part of the Hawkes Bay Trail Run Series.
A lot of people use running as a means to support charity. Why do you think that is?
Because it is something that nearly any person can get off the couch and do. Also, many of us are touched, as I was, by the fabulous work of charities in the community and feel a need to go beyond "a dollar in the bucket".
Q. What did your friends and family think of this idea?
At first my family thought it was just a crazy idea that would fizzle out; now they are fully supportive. My non-running friends still think I am nuts and a few running ones think that the jury is still out.
Q. What advice do you offer to people struggling with challenges?
Change the things you can and don't stress about the things that are beyond your control. Turning your life around starts with one step.
Mike Tennent's 52 in 52 mission
When: Saturday, May 4, 2013 to Saturday May, 3, 2014
Where: All over New Zealand
What: Mike is running 52 half-marathons (or longer) in 52 weeks
Goal: To raise at least $20,000 for the Hospice Charity. He has raised $42,508 (pledged)
For more information or to support or join Mike, visit www.52in52.org.nz
Next four running events for Mike Tennent
1. Today: Double Rainbow Trail Run, Rotorua (24km)
2. Tomorrow: HBTR Pukeora Pickled Pukeko, Hawkes Bay (21.1km)
3. June 23: Armstrong Motor Group Wellington Half Marathon (21.1km)
4. June 30: Blackmores XTERRA trail run and walk series: Waiuku (21.1km)