There’s always someone you can rely on to put you down.

“You?” this person scoffed when I told them about my goal of raising £2,000 for Winston’s Wish by walking across the South Downs in May 2012. “But you’re never going to make that. Why are you even trying?”

Normally I wouldn’t bother answering. There’s no point. It doesn’t matter how well you present your argument and steely determination, negative people will always pick holes in what you’re saying and I can’t be doing with anyone who is so dissatisfied with their own life they try to sabotage yours as well.

This time though, I did things differently. I shrugged my shoulders, told her she was mistaken and that, whether she believed it or not, I wasn’t going to wimp out due to a blister on my big toe. More importantly, I would hit my fundraising target.

And it’s not just a case of me being optimistic with nothing to back me up. I have proof. After only one month of blogging and walking and canoeing, I’m already past the £400 mark, which means I’m over a fifth of my way there. There are another ten months to go before I officially lace up my walking boots and trek over the South Downs and if I pull in the money at the same rate as this past month, then Winston’s Wish is going to get a massive cash boost.

A few friends have already sponsored me. If you click on my sponsorship page virginmoneygiving.com/emma_bird, you’ll see their names: Emma, Simon, Lilly, Tamara. These are some of my Premier League friends, the ones who were there for me in those dark, confusing days, weeks and months after my brother killed himself and are there again now because they’ve seen firsthand the damage that suicide wreaks. They also know how much this challenge means to me and the rough, emotional rollercoaster of a journey I’ve been on to get where I am today.

However, it’s the other people sponsoring me that has thrilled me the most. Former colleagues, online connections and total strangers. Unprompted, they are donating their £1, often a lot more, proving that just a tiny amount really does make a difference. It reminds me of a cardboard print I bought on a school exchange to Osnabruck, in Northern Germany, when I was 15.

I can’t remember where I found it or what I paid for it, and I certainly have no idea how it’s survived multiple house moves around Britain, France and Italy. But it has and I’ve still got it hanging around the flat. It reads: Many little people, in many little places, doing many little things can alter the face of the world.

Or, in terms of The Big Em and M Challenge, a child’s future. And all for only £1. That’s less than a cup of coffee. Which is a total bargain when you think about it.

The fact is, there are just too many children facing life without their parents and their brothers or sisters. The mum of one of the little girls I teach has terminal cervical cancer and, suddenly, the vibrant, funny, confident seven-year-old I love has been replaced with a shy, insecure substitute who draws sad pictures and can’t express her feelings.

Unfortunately I can’t give her back her laughter but I can – and so can you – help make sure another child gets the professional support they desperately need. And, actually, it’s the thought of those children that got me out of the house this past week. Last Saturday, I went out canoeing with Mario and he outpaddled me, despite not having been out on the water in a couple of months.

It didn’t make any sense until the following morning when I woke up with a clammy forehead and my throat scratchier than a piece of sandpaper.

I should probably have stayed at home, lying listlessly on the sofa but I knew I had to get a walk in, even if it was only ten minutes down to the shops and back. During the first few days of being ill, that was enough.

But this morning I woke up early and went out for an hour’s walk before having my morning coffee, which is usually the only thing that gives me the adrenalin I need to get going. And I’ll be going again this evening when I finish working for the day.

So that’s that. A month ago I hadn’t read ELLE, I hadn’t been to Barcelona and I hadn’t walked up those killer steps to my brother’s flat and realised how unfit I actually was bar the odd 20-minute run and occasional yoga session.

And now here I am canoeing regularly. I’ve ditched the car and am going out for a couple of longer walks every day, too. I feel like shoving the proof in Ms Sceptical’s face but I’ll do that next May once I’ve passed the finished line and got the blister on my big toe.

But you know what my real secret is? A new pair of snazztastic trainers, although I have dirtied them up a bit just so I can look like a seasoned pro. It’s not so much that they’re brand new, more that they’ve got the most fabulous go-faster stripes along the sides – and we all know how much better souped-up boy racer cars perform than their sans stripes counterparts. I trust they will have the same effect on me.

Given the evidence to date, all I can say is this: Jessica Ennis, with only 18 days to go until the start of the Olympics, your Gold medal is under threat.