CHRONOLIGALLY speaking, I have nine more months to enjoy the last year of my 20's before the big 3-0.
But biologically speaking, I've already passed that milestone, as I discovered on a recent trip to the set of The Biggest Loser at Manly in Sydney's northern suburbs.
During my visit I took part in the reality weight-loss show's BioAge fitness test.
Developed by University of San Francisco Professor Paul Taylor, the test determines a person's physical age based on metabolic, physical and behavioural measurements.
Biggest Loser trainers Michelle Bridges, Shannan Ponton, Tiffiny Hall and The Commando help Taylor try out the latest version of his test on us journos.
First up was the easiest part of the test - the metabolic measurements of blood pressure, body mass index (BMI) and lung capacity.
Then it was time to test some of our physical fitness with The Commando.
With some of the contestants cheering us on, we first had to hold the plank position for three minutes.
As one of the two people in my group to make it to the end I was feeling pretty good, but following the plank with a push ups test turned my arms to jelly.
A final, and less than flattering, overhead squat tested our overall flexibility with The Commando pointing out any weaknesses.
Had the test ended there, I would have done pretty well but the trainers saved the best for last - the beep test.
Running back and forth along a 20-metre track, the test measures cardio fitness.
The first few laps were relatively easy but as the time between the beeps got shorter, I could feel my heart rate rising and my legs were tiring.
Seeing me start to fall behind, Shannan comes over and runs next to me, saying things like "discover something about yourself".
He gently presses two fingers on the middle of my back between my shoulder blades and seems to will five more laps out of me.
As we cool down Taylor puts our results into a computer program to calculate our BioAges.
We all wait nervously in the living room of the Biggest Loser house as he hands out our results.
I'm not surprised at mine - 31.
The figures are broken down by colour, blue indicating average results for my actual age, green for better than average and red for less than average.
Aside from a slightly below average lung capacity, the only thing that let me down was the beep test.
Taylor talks us through our results, which include three-month goals to improve our BioAges.
He says setting and achieving short-term goals is the best way to maintain motivation, and it's exactly what they encourage the contestants to do on the show.
Tonight, the latest crop of Biggest Loser singles will find out their BioAges.
Along with their initial - and emotional - first weigh ins, the BioAge test serves a wake-up call, quantifying just how much harm the contestants have been doing to their own bodies.