The 43-year-old is not only trying to lift as much as he can, he is looking to act as a role model for his children.
He claimed his third consecutive national championship medal on day one of the national classic powerlifting championships in Dunedin yesterday.
Competing in the 120kg male masters 1 category, for 40 to 49-year-olds, the Central Districts lifter pulled out personal bests in all three lifts to finish third.
It was quite an impressive feat, after he took up the sport only four years ago.
''I quit smoking and I wanted to show my kids that it's good to be healthy and doing active sport.
''So I went and did my first novice competition as basically just something to do and got hooked.
''I was a heart attack waiting to happen: high-stress job, smoking, not doing any exercise and eating poorly.
''So I thought, I've got to do something, or I won't see my grandkids.''
He finished with lifts of 250kg in the squat, 165kg in the bench press and 255kg in the deadlift.
That left him with a combined total of 670kg.
Both the bench press and deadlift were 5kg personal bests, while the squat exceeded his previous best by 10kg.
He attempted a final deadlift of 260kg, to try to edge into second - which would have matched his 2015 placing - but it was not quite there.
The result pointed to the lifters getting stronger, he said, having won last year's competition.
''I was really happy with today. It was a fantastic competition and just to be able to be competitive, I was super happy.''
A manager at the New Zealand Customs Service, Dennis trains three times a week, generally doing all three lifts and getting better at them through repetition.
There was a process, though, as he looked to go through different phases in his build-up.
''You start off with what you call a building-block phase, where you do heaps of reps, just to get conditioning.
''Then you try to put some muscle mass on and then you peak for strength, so it's a process.''
As for eating, he did not have a specific secret recipe.
''I have to admit I'm not in the [under-105kg class],'' he joked.
''I do try to keep it clean.
''But in the peaking cycle I eat anything. I'm just hungry all the time.''
He lives in Wellington and has been trained by Trevor Walker for the past two years, after initially starting at the Power House Gym.
The class was won by Manu Pihana with a combined total of 697.5kg, while Leon O'Connor was second with 685kg.
The competition continued yesterday afternoon with the masters females and sub junior/junior females.
There were plenty of New Zealand records on the first day of the championships, which continue through to Friday evening.
