Sometimes its tempting to just keep banging out the extra miles. But what you’ve always done to prepare for an event, may not be the right thing, or even the best way to make use of limited training time. A number of recent physiological studies have found that greater endurance returns can be made from high intensity and supra maximal training as opposed to continuous running. High intensity training (HIT) involves running intervals at 80-90% of V02 max (i.e. maximum volume of oxygen that the lungs and heart can deliver to, and be used by, the muscles) – in other words 9 out 10 for maximum, all out running. Supramaximal intensity interval (SMIT) training involves running at 100% or above of V02 max. Cicioni-Kolsky and others in 2011 found that SMIT gave the most benefit when compared to either HIT or continuous running, after 6 weeks training, when assessed on 3000m time trials. Gibala and others in 2006, found that sprint interval training (which could include both HIT and SMIT training) was both time-efficient and produced adaptations, both muscular and in terms of performance, comparable to more typical endurance training. So if you are time limited, or just becoming stale in your training, more miles may not be the answer, pushing times and speed in interval training could provide the required returns.