Sometimes, watching your watch isn't helpful: rigidly running to set kilometre splits means you can spend energy that you can't afford, and miss your target time. The answer? Keep your effort consistent instead.

The best runners use either heart rate monitoring or perceived effort to monitor intensity. Both methods are effective; use them and you'll soon learn how to hit your target every time.

Measuring your heart rate is an objective way of peeking inside your body to see how hard it's working. Longtime runner Emma Wilton used it to improved her running. "I wore a heart rate on easy days to make sure I was in the recovery zone," says Wilton. The slower pace allowed her to increase her weekly mileage from 30K to 85K, which helped her shave two minutes off her 10K time.