can slow your finish time by several minutes, and heat or cold by even more. A survey of marathon finish times suggests that 12°C is the ideal temperature, a temperature of 0°C or 25°C adds seven per cent to your time, and if the day hits 30°C, you can

." Should you try it? These programmes seem well suited for overbooked or injury-prone runners. Studies and surveys of marathon runners have validated this approach by finding little correlation between weekly mileage and marathon performance, especially

." Should you try it? These programmes seem well suited for overbooked or injury-prone runners. Studies and surveys of marathon runners have validated this approach by finding little correlation between weekly mileage and marathon performance, especially