As someone who clocks two 7km runs a week, I thought that five-station metabolic circuit training at Maju Camp would not be a problem.
How wrong could I be?
The Clementi Road army camp has long been dreaded by unfit Operationally-Ready National Servicemen (NSmen), who must report there once or twice a week to be whipped into shape.
I joined 20 NS men for the newly revamped physical training programme, which aims to help them pass their Individual Physical Proficiency Test (IPPT).
On a muggy Monday night, even the pulsating beats of electronic music coming from speakers did not seem to pump up any of my group.
The new-look IPPT Preparatory Training (IPT) programme appears more attractive with five different options to choose from: weight loss, aerobic, metabolic, IPPT-specific training and sports and games.
And with the latter including football or basketball, NSmen could be forgiven for thinking that things may have been made a little easier.
I chose metabolic and our group had to do seven repetitions at five stations, which makes up one set.
The fitness trainer tagged to me, Mr Tan Wei Xian, said I should try to complete five sets in 15 minutes.
I was quietly confident that I could hit that target.
But after thrusting medicine balls while executing star jumps, lifting kettlebells while doing half squats and doing wide-arm push-ups, crunches and burpees, I could already feel the strain.
I pushed on. Under the glare of Straits Times cameras chronicling my experience, there was no way of dodging the hard work.
I could feel that my arms were not lifting as high and I was shuffling rather than running, hoping that time would be up.
When the whistle was finally blown I had managed only two sets.
I was sweating, panting and seeing stars - but still the ordeal was not over.
Next up was the much-feared Tabata workout, which involves push-ups and 45 degree flutter kicks.
We were told to go as hard as we could for 20 seconds, then rest for 10 seconds - a process to be repeated 10 times.
The seconds seemed like an eternity.
My head and hips sagged. My kicks flapped rather than fluttered.
Looking around me, some of my contemporaries appeared undeterred, kicking away with gusto.
But the high-intensity workout was wrecking my body. I wanted out.
Wei Xian asked politely when I had last exercised.
"Last week!" I grunted indignantly. "I even clocked 6km within 30minutes."
But I knew that my wretched performance in the 75-minute workout was a damning indictment of my fitness.
Clearly, I'm not in great shape.
But the new IPT programme stretched my physical limits. My body is still sore, three days on.
There is no doubt other NSmen who want to toughen up will be better off for it.