With last year's Olympic Games still fresh in my mind, and with a summer holiday in Greece just around the corner, I have redoubled my efforts at the gym. One of the core values of our school is "aim high", so I am aiming for physical perfection. It is a tough journey. But when I stop mid-bicep curl to admire the Adonis-like figure staring back at me from the mirror, it is clear that a combination of aspiration, perspiration and several tubs of whey protein can pay huge dividends.
I gaze in speechless admiration at the sight of rippling abdominals under a tight-fitting Lycra vest, at the perfect V made by thrusting deltoids tapering to a trim waist. Adjectives alone cannot describe the powerful quadriceps, the tumescent calves, the rock-like pectorals and the glorious glutes. This is what Michelangelo's David would have looked like had he been sponsored by Adidas.
I shift my gaze slightly so I am no longer staring at the man standing next to me, who I think may be contemplating punching my lights out. Seeing us side by side, I am reminded of the film Twins. One of us looks like Arnold Schwarzenegger, and it's not me. But does the fact that I'm far too short and bulge in all the wrong places mean that I can never hope to reach the pinnacle of athletic distinction?
Maria, my German personal trainer, who has a "never say die" attitude to extending my fitness levels, must have wondered this herself. I told her that my targets were to tone up my muscles, improve my body image and wow the ladies at the hotel pool. The shadow of doubt that flitted across her face briefly dulled her healthy glow.
It is good to know that even the likes of Maria are subject to moments of self-doubt. It makes me feel better about having a mild panic attack when I am advised that a child who nature and nurture have conspired against in terms of reaching intellectual prominence must make a leap in attainment equivalent to conquering Everest without oxygen.
"Surely there has to be some sense of realism," I tell my wife, collapsing beside her on the sofa after a gruelling cardio workout. "Are we not all individually bound by our physical and intellectual limits? Are we not simply victims of natural deselection? I can never be Michael Phelps, just as Bradley can never be Einstein."
"No, and I'm never going to look like Nicole Kidman," my wife sighs. In the interests of marital harmony, I resist the temptation to agree with her.
"I liked the world before they banned negativity," I say. "Life was a lot easier when you could express doubt, give up after three attempts, and generally opt for the line of least resistance. Too much positivity can be a dangerous thing, you know. It encourages those who clearly can't to believe they actually can."
Maria's self-doubt turns out to be fleeting. At our next session, she demonstrates renewed resolve by increasing the speed and incline on my treadmill. I try to suggest that it may be a good idea to reduce expectations but all I can do is gasp.
Steve Eddison teaches children aged 7-11 at Arbourthorne Community Primary School in Sheffield, England.