Concepts

How do I use threshold power? Your threshold power is an important measure of your running fitness. It’s used to: (1) set training targets – as a percentage of your threshold power; (2) monitor training load – by calculating training load scores (relative to your threshold) for every workout; and, (3) set race/event targets – as your finish time will depend to a large extent on your running fitness (your threshold power).

How do I find my threshold power? You can find your Threshold Power using specific models and test protocols. The three most commonly used models are a Critical Power test (CP), modelled Functional Threshold Power (FTP) and Automatically calculated Critical Power (Auto-CP). The models differ but are similar in their approach and purpose – they: (1) use the results from two or more maximum effort runs at differing durations; (2) identify a power level that’s close to (or within) your threshold; and, (3) do not rely on lab tests – instead, they are field-based.

What is Threshold power? At lower intensity levels, your body achieves a metabolic steady(ish) state and you can sustain your effort for an extended period. Researchers call these domains ‘moderate to heavy.’ At higher intensity levels, you can’t achieve a metabolic steady(ish) state. You’ll fatigue much more rapidly and need to slow down or stop. Researchers call these ‘severe to extreme’ domains. The change from heavy to severe doesn’t happen at a precise point – it’s a ‘phase transition’ over a narrow range of intensities, with lots of metabolic changes occurring at different rates and in parallel. Threshold Power is an intensity that’s within (or close to) the phase transition from heavy to severe – other names for this phase transition include Anaerobic Threshold, LT2, VT2, Critical Power and more.

Isn’t power just for elite runners? No – in fact, non-elites may benefit more from power than elite runners, who’ve spent years developing their ‘feel’ for how hard they’re running. Elites can still Run with Power, but non-elites may may get the biggest benefits. As one runner commented, “I honestly think it helps weaker/slower/newer runners even more than experienced fast runners. It’s like having a coach in a pod!”

Why does power jump around? It’s because your body produces energy stochastically, while your power meter produces a number every second – which can be high, low or somewhere in the middle. Using power averaged over 3 seconds (smoothed power) can remove the ‘spikyness’. When running interval workouts, targets will normally be given for each work interval (each lap), which you can show on your watch as a Lap average.

Is power better than pace or heart rate? Power solves issues associated with other measures of running intensity. There are a few things that are different about running with power. And like any new approach, there are some things that take some getting used to; things that will get easier as power usage spreads and the tools develop. However, after running and coaching with power since 2018, I think it’s already the most effective way to train and race.

Does running power measure effort? No. It provides numbers that represent your effort. But those numbers are usable if they are repeatable and valid – and they are. Which means you can successfully train and race using power.