To anyone who’s been tempted but who worries about running in the dark, let me offer some encouragement: if you can run, you can run with a head torch. Some of the best runs I've done have been in the dark, away from the glow of streetlights altogether.
When you're running with a suitable head torch, you've got a personal patch of light right there in front of you. In time, you can go full tilt, but for starters, it’s fun to just get out and feel the excitement of the night air, noises, shadows and sense of adventure.
Until I ‘saw the light’ a couple of years ago, I made do with a £5 camping head torch. While my co-runner’s path was bathed in brilliant white light, I might as well have been running by candle. So I invested in 180 lumens of adjustable, comfortable, lightweight torch, and can now flood the ground with light to avoid trips, or fire a spot beam up to 150 meters in front of me to search for gates, stiles or obstacles. Most running-specific head torches will allow you to alter the focus and power output, which means saving battery life – though many may last for a good 8 hours if used with the right batteries. They weigh next to nothing, and some can even be recharged from a laptop computer's USB port.
While you're out there, just be mindful of others in the area – animals as well as people. Be aware of the natural habitats nearby and aim to avoid disturbing them as far as you can, particularly during bird breeding season (March-July). Also, make sure your light pollution is as minimal as possible, by directing your torch away from houses and turning it off when it's not needed.
A growing number of running clubs are now leading group runs at night, offering safety in numbers for the uninitiated. You're free to try out the experience with the Hash House Harriers without any membership fees. Even some specialist retailers lead night runs, and will lend newcomers all the vital equipment to try it out and decide whether or not it's for them.
So next time you're worrying about winter's lack of light causing a gap in your training, get yourself a decent head torch, call a buddy, and plan a night run.