What

Power Meter questions. Answers to the following: Running power meters don’t measure the force being applied – how can they calculate power? Garmin numbers are nothing like Stryd numbers – how were they correlated? Sounds like there’s no standard for running power? Which is the best Power Meter?

Can you use a running watch to Run with Power? Yes! All the major running watch manufacturers (Garmin, COROS, Wahoo, Suunto, Polar, and even Apple) include wrist-based power in their newer models, and using a running watch means you won’t need to buy a separate power meter. Downsides? There are no independent studies testing whether wrist-based power provides repeatable, valid power numbers. However, I ran my own (N=1) study and found the watches I tested produce repeatable numbers that, for recreational runners, are correlated to the Stryd footpod. Setup is more complex, and you’ll need to connect a few different apps. Finally, few running watches produce power numbers when running on a treadmill. But it may be a budget-friendly way to try Running with Power.

Can you use a Stryd footpod to Run with Power? Yes. It’s a power meter that works with all major sports watch brands, with Apple Watches, with mobile phones, and with some smartwatches. It provides power-based metrics, accurate speed and distance (even in poor-GPS locations) and some additional metrics that measure your running form. It works outdoors or on a treadmill. It produces repeatable numbers that are highly correlated with O2 consumption (a gold standard for measuring exercise energy consumption). The footpod comes with the Stryd Ecosystem, an end-to-end solution (from planning through reviewing) that’s built around running power.

Do running power meter produce usable numbers? Running power meters provide numbers showing how hard you’re working when you run – your effort. But are they really measuring your effort? Running power meters provide numbers that represent your effort, and can provide usable information … as long as the power numbers are repeatable and valid: Repeatable? The same effort under the same conditions gives the same result; Valid? The numbers are highly correlated to an existing ‘gold standard’.

What is a power meter? A Power Meter provides numbers representing how hard you’re working – your effort or running intensity. Running power meters use readings from multiple sensors to calculate a power number. Most recent running watches have a power meter built in.

What advice would you give to someone not yet Running with Power? Based on feedback from runners using power, the top three pieces of advice are: 1) Learn the fundamental concepts to get the most from running with power; 2) Use a training plan designed for power (not one where pace or HR targets/workouts are simply replaced with “equivalent” power zones; 3) Trust in the process – start by wearing the footpod, then begin looking at the metrics, finally move to power as your primary metric.

What difficulties have you experienced? Based on feedback from runners using power, the top three difficulties are: 1) Getting Started – There is a learning curve associated with using power, including the fundamental concepts that power is based on and things you should and shouldn’t do … however, these are well-known, documented and often discussed in the power-focused Facebook groups – it just takes time; 2) Maintaining a valid Threshold Power – Threshold Power models and protocols rely on maximum effort runs, and it’s this aspect that runners found difficult; 3) Learning to run using power – runners reported that it took time to fully trust power, and to stop relying on the other metrics.

What benefits have you experienced? Based on feedback from runners using power, the top three benefits are: 1) Able to train to targets (based on your individual fitness); 2) Consistency. Runners experienced a powerful feedback loop: targets matched to fitness => able to run to target => confidence in the plan => increasing fitness without injury => adjusted targets matched to fitness => able to run to target; 3) Improved race-day performance – Power offers a couple of different race planners, both of which produce power-based targets for races and events that are not only achievable, but for many runners, accurate to within a few watts and to within a minute or two (over a marathon).

Feedback from runners using power. The posts in this topic group summarise feedback from two annual surveys, and feedback gathered while researching two of my books (‘Why’ and ‘Getting Started’), when asking runners the following questions: Why did you start running with power? What benefits have you experienced? What difficulties have you experienced? What advice would you give to someone not yet Running with Power?

How can I estimate my finish time? There are two different race calculators you can use to estimate your finish time: the web-based Stryd Race Calculator; the ‘Generate Race Power Scenarios’ feature in SuperPower Calculator (for Google Sheets). Whichever calculator you use, they work similarly, using your race-day running fitness (Threshold Power), your fatigue resistance (two different metrics, depending on your event distance), and how effectively you convert power into speed (Running Effectiveness) – to obtain a personalised race-day target.

Can you measure changes in fatigue resistance? You may be familiar with the term stamina, which is similar to, but not the same as fatigue resistance: Stamina – your ability to sustain effort for a longer duration; Fatigue Resistance – your body’s ability to resist the effects of fatigue. You can use Running Effectiveness to measure fatigue resistance. You can improve fatigue resistance through a well-structured training plan integrated with strength & conditioning.

Can you measure running form improvements? You can, but it’s not easy. You can use strength and conditioning, running drills, plyometrics, and other supplemental activities to improve ‘how’ you run (whether your movements are efficient, stable, and injury-free). And you can use Running Effectiveness to determine whether your changes have improved your ability to convert power into speed … or not.

How do I use Running Effectiveness? Running Effectiveness (RE) uses speed and power (effort) – both are measurable numbers, so RE is easy to calculate. But Running Effectiveness measures how effectively you convert power into speed, and there are many things that can affect that conversion: Your running intensity; Hills; Wind; Running shoes; Your power meter & weight changes. One way to monitor changes in RE is to use reference runs – runs you include every 3-4 weeks in your training plan, where you run the same route at the same target intensities in the same running shoes. Reference runs aim to minimise variations between runs, so that you can compare RE between runs and confirm improvements.

What is Running Effectiveness? Running Effectiveness (RE) was proposed by Andrew Coggan, PhD, and measures how effectively you convert power into speed. It’s a field-based measure similar to, but different from Running Economy (oxygen consumption at various speeds) or Running Efficiency (external mechanical power vs. metabolic power production), which both require lab-based testing. RE = speed / power, where speed is in metres per second and power is in Watts per kilogram.

Mixing your training intensities. A Training Intensity Distribution (TID) chart groups your time spent at each intensity into 3 or more zones, then displays the result as a stacked bar chart, with each stacked bar representing a week of training. The chart can show percentage of time in each zone (with the stacked bars all the same 100% height), or actual time spent in each zone (with the height of each zone representing the time spent in that zone). The TID chart is the third key metric for monitoring your training (along with Training Load Balance and Ramp Rate).

The danger of ramping up too quickly. Your Ramp Rate shows if you may be adding training load too quickly, replacing ‘the 10% rule’ with a metric based on your training volume and intensity and calculated from your completed runs. Your Ramp Rate is the week-on-week difference in your Chronic Training Load (CTL) or your 42-day weighted average, depending on which set of metrics you’re using. Why week-on-week? Because Long Runs will tend to impact your training load more than shorter interval sessions or easy/recovery runs. Using a week-on-week calculation will ‘smooth out’ any fluctuations caused by your workout mix while still producing a useful metric.

Balancing your training load. Training Load Scores, calculated for each workout, represent each workout’s metabolic stress. You can use these scores to model the shorter-term and longer-term impacts from each workout. Combining these, you can obtain a Training Load Balance (TLB), indicating whether your training is ‘productive’: A very positive balance indicates detraining or a lack of any meaningful training; A positive balance may indicate tapering or a missed workout; A negative balance indicates productive training – enough load to encourage adaptations, but not so much that there is a greater risk of injury or over-training; A very negative balance may indicate over-training, with a greater risk of injury.

The impact of training. On one side of the coin, the reason you’re training – improving your performance, your fitness, your speed, your ability to run further for longer. On the other, the impact of your workouts – fatigue, muscle soreness, dehydration, injury risk … the list could go on. How can a single Training Load Score (per workout) fully model training load – both the shorter-term impacts and the longer-term improvements?
The Performance Manager model (Coggan et. al) uses your Training Load Scores to calculate personal training metrics that indicate whether your training is productive – not too much, not too little, just right for you. And with two different load metrics (ATL and CTL), the model includes both the shorter-term impacts and the longer-term improvements.

What is Training Load? Your Training Load is the cumulative load from your training workouts. It’s easy to overdo it, leading to injury and time spent recovering (rather than training). But if you’re training for an event, regular (and repeated) workouts are a necessity. It’s a balance. Load your body too little, and it will not adapt; load it too much or too quickly, and it will break down instead of adapting; load your body correctly, and sustained long-term improvements are possible.
How can you monitor your Training Load? Using a Training Load Score calculated for each workout. Training Load Scores combine ‘how hard?’ and ‘how long?’. They represent each workout’s metabolic stress – its impact on your body from the workout intensities and durations. Training Load Scores are the foundation for metrics you can use to monitor your training load.

Is my PDC accurate? To ensure your PDC is accurate – that it represents what you can actually achieve right now: your training should include maximum effort runs for a range of different durations, so that your last 90 days of workouts includes a maximum effort for each duration; you should run maximum efforts every 4-6 weeks, alternating between durations, so that your Threshold Power (and your PDC) accurately reflects your current capability.