Maybe a co-worker has talked you into taking part in the upcoming company run. Or you’ve resolved to take on more sporting challenges and registered for a 10-kilometre run or half marathon in your city. How best to prepare? If you’re an inexperienced runner, you should consider your fitness level and whether you’re really up to the undertaking. “It’s probably a bad idea to prepare for a marathon if, for example, you’re overweight or have a cardiovascular disease,” says sports medicine physician Dr Thomas Schneider. He advises novice runners to first consult their GP, who can give them a medica…