Cian Healy's weight as a professional rugby player has varied from 97kg when making his Leinster debut 13 years ago up to 127kg at the 2015 World Cup.
The loosehead prop has adapted his weight through the years to the requirements of the sport.
"Throughout it, I've had wild changes," Healy told Marie Crowe as part of McSport's My Motivation interview series.
"I started professionally with Leinster and I was 97kg. That's incredibly light for my position and that was a big problem at the start. Michael Cheika just threw me in and said, 'You have to deal with it and you have to work on getting your weight up as well'.
"I've also gone up to the other end: In 2015, for the World Cup, I was 127kg. It's a pretty big scale to be swinging on. When I was 127kg, it was like trying to turn a bus. The lighter you get, the small the car gets. It's easier to move, get around and react when I'm a bit lighter. I felt awful running around. I felt like I was constantly chasing the game, never ahead of myself."
The Ireland international now plays at around 110kg - 113kg due to the increased fitness demands on the pitch.
"I think that's a pretty good fighting weight to be able to get around the park easily and be able to do my main job as best as possible", he said.
"I've tested the water at all different weights. I've bulked up to that (127kg) and I did a season or two around 118kg, 119kg and I was pretty fit and quick around that.
"In the last two seasons, I've dropped it down again just to try and boost that fitness side of it a bit more than the strength side of it. I'm pretty happy with where the strength is at, at that weight.
"I'm definitely adapting my weight now to how the game has gone. There's less of running start at scrums now - they're more controlled.
"Fitness has become way more important; there are less stops in a game, more ball in play time. For me to be the best asset to the team that I can, I'm shedding off a few more kilos and working more on fitness."
Sports & Fitness Specialists, McSport, welcomed Cian Healy as the final guest in their MY MOTIVATION campaign interview series.
Photo by Conor Sharkey for Leinster Rugby via Sportsfile