By Jenny Dickinson

So there's been a setback. I should have known that marathon training was going too well. Last weekend, on a standard 10-mile run, I twisted my ankle. A proper sprawled-across-the-pavment-with-shocked-tears hummdinger. After a kind motorist stopped to offer me a lift home (there were plenty that drove straight past) and I was lying prone of the sofa, foot up on a cushion, packet of frozen vegetables wrapped in a tea towel in place, I started calculating. Two days off means I'll miss one session of speed training; a week off means I'll miss a distance run, a speed run, a spinning class and core-strengthening session. More than one week off? Well, that might mean I miss the San Francisco marathon altogether.

After getting the injury checked out to make sure it was just a sprain, the depression and doubt hit: what if all this effort was for nothing? Maybe I should just pull out now. Luckily for me, I get a call from Olympic athlete Jeanette Kwakye. I feel a bit of a fraud, because Jeanette is an actual professional runner – in 2008 she became the first woman to compete in the Olympic 100 metre final since 1984 – and she's recovering from a knee injury that could have wrecked her career. 'I had an operation on my knee last november,' she says. 'After a week I was back in the gym doing Pilates and working on a standing leg bike programme.'

If you're in training, while it's important to rest your injury and allow the body to heal, there are ways to try and preserve your levels of fitness. The bike, for example, puts far less pressure on joints than running – less impact. 

But what about mentally? That's what I'm really struggling with, staying positive. 'When you're injured is the time to concentrate on improving areas you don't usually train, such as your upper body,' says Nike Athlete Jeanette. 'It gives you something to focus on. You've got to see the injury as a minor blip, the power of the mind will help you move forward. Go at it slowly but surely, no haste.'

She's right of course, and a session with my Nike trainer Sonja working with Kettlebells to build my core leaves me feeling as though I've still achieved something, despite my setback. San Francisco, here I come.