Close your eyes. Imagine yourself at the starting line, the adrenalin is pumping, your heart is pounding and the gun fires. Suddenly your legs explode to life and you're tearing up the track, the cheers from the crowd carrying you forward and you leave the race rubbing dust from your eyes as you cross the finish line in first place.
Professional runners have for a long time been aware of the benefits of mental rehearsal. If you're any good at visualisation, it's an effective way to prepare for a race.
No matter how vivid your imagination, nothing can compare to the physical experience of actual training. So what if there was a way to practice all the aspects to becoming a great runner – form, technique, pace – without moving a muscle? The answer lies not in our waking lives, but in sleep.
Charlie Morley is a lucid dream expert who runs workshops around the world. He believes there's no better way to prepare yourself for a gruelling marathon than rehearsing in a lucid dream – an elusive state in which you consciously know you're dreaming during the dream.
"Studies have shown that if you spend your lucid dream running, the neural pathways engaged in the ability to run are strengthened, not just visualised or imagined," he explains. "So when you wake up in the morning, you will find running easier."
The first step, of course, is learning how to get lucid in your dreams. The next is deciding what to do when you're finally there.
The important thing is that you don't have to create the perfect training environment to practice in a lucid dream, Morley explains. Forget about conjuring up a track and finding a pair of comfy trainers. You're in a mental construct, so wherever you find yourself – be it the mean streets of London or inside a giant tea cup – stop what you're doing and run.
"As you run, know you're dreaming and know you are training for real life," he suggests. "As you run, call out: 'I am the best runner I can be. I am in tune with body and mind.' A lot of people training for a marathon hate running by the end of it. If that's the case, just start running in your lucid dream and shout: 'I love running!'
"It works in the same way as a hypnotist guiding you into a trance and engaging a statement of intent. But I would argue that it's working deeper than that. Whereas hypnosis works in the shallows of the subconscious, lucid dreaming works with the depths of the unconscious."
For some, the lucid state remains unreachable. The next best thing, Morley reveals, is to spend some time in the hypnagogic – the dozy, transitional state that we fall asleep into.
When you feel yourself starting to fall asleep, start engaging those statements of intent, he says. Then you can also visualise yourself running, finding your perfect start and pace. By spending time in that state you are training yourself to have lucid dreams.
Lucid dreaming may sound kooky, but scientists are taking its potential for improving sport performance seriously. While early studies by German psychologist Paul Tholey pointed to a link between lucid dreaming and an athlete's improved performance in waking life [PDF], new research from Heidelberg University suggests that practising sport in a lucid dream is not just a frivolous fantasy. As far as your mind is concerned, it's for real.
In an experiment by Daniel Erlacher the possibility of practising a simple motor task in a lucid dream was studied by asking participants to toss as many coins into a cup as possible. Incredibly, those who practiced the task in their lucid dream showed significant improvement when asked to play the game again the next day.
And this is just the beginning. Heidelberg doctoral student Melanie Schaedlich and her colleagues are now digging deeper, using experiments and data to show that athletes can actually benefit from practising movements in lucid dreams.
"We have to do more research using brain imaging techniques to show that actually, as we assume, the same neurological structures are activated during motor activity in lucid dreams as in wakefulness," she says. "The evidence we have from previous studies is promising."
The potential for using lucid dreaming on both an amateur and professional level is huge, but we may have a long way to go before lucid dream practice becomes part of standard training schedules for athletes. However, it would seem that science is close to proving that practising sports in a sleeping state is beneficial.
For many runners, struggling to squeeze more training time into an already packed working week, the promise of an injury-free midnight jog round the block or even the dark side of the moon could be a dream come true.