Let’s have a look at three practical examples of the benefits of power within a workout;
Short and sweet: The image below shows the power and HR readings for part of a training session that involved a series of short, 40-second fast hill intervals. The image shows that power has been able to pick up the intensity of the session but the HR ‘lag’ does not accurately represent the loading of the session with HR not rising much beyond a steady effort. The image also shows how HR actually peaks after the effort is over. Using power for short, faster efforts like this provides a much more responsive and accurate workout measure.
Finding your ‘threshold’: Combining power and HR data can be a highly effective training tool. The data in this image shows a simple test run of 10-minute,
8-minute or 6-minute efforts – all run on the flat at a HR (red dots) that correlates to anaerobic threshold effort as determined by a recent lab test. This has allowed us to determine a power measurement when running at anaerobic threshold effort (around 400 watts). This data can now be used to run threshold and tempo sessions much more consistently in the hilly training environment in which this athlete finds themselves, using power as guidance, not pace or HR.
Finding the hard in the easy: Many athletes run their recovery efforts too fast. Sometimes ego can get in the way of allowing your body these crucial easier periods between hard sessions, to adapt and progress – with runners often ending up perpetually fatigued. HR is often used as a tool to keep easy runs easy but, for faster runners, understanding the ‘external load’ of, for example, completing an easy run at 7-minute miles as opposed to 6-minute miles can be very useful, even if your HR is low for both efforts. These two images show sections of two ‘easy’ runs according to HR. One was undertaken at a relatively steady power output as it was run on a traffic-free route. The other was run in a town which led to ‘surging’ of power throughout the run. Average HR was the same on both runs, but power allows us to see that the first run had less muscle load.
Is it everything? Like all data, whether HR, GPS or recovery measurements, power is a tool for athletes and coaches. It can allow more accuracy in measuring the effectiveness and loading of sessions and help give a fuller picture of an athlete’s performance but it shouldn’t be used blindly. Coaching isn’t a purely technocratic process of assigning plans and checking statistics. Perceived exertion, coaching craft and of course communication will remain at the heart of all good coach’s practice. Used wisely and with care, power can really add to a coach or athlete’s toolkit.