Tag: Testing

𝐏𝐨𝐰𝐞𝐫 𝐀𝐩𝐩𝐬 – 𝐈𝐧𝐭𝐞𝐫𝐯𝐚𝐥𝐬.𝐢𝐜𝐮

Intervals.icu analyses your rides, runs, swims and other activities (with and without power). It provides basic and advanced analytics and planning in an easy-to-use web interface with support for desktops, phones, and tablets. Intervals.icu is free to use, with additional features should you choose to subscribe.

It can calculate and display all the most important metrics … and then some.

𝐈𝐧𝐭𝐞𝐫𝐯𝐚𝐥𝐬.𝐢𝐜𝐮 𝐌𝐞𝐭𝐫𝐢𝐜𝐬

✅ Threshold Power. Intervals.icu can calculate threshold power (using your choice from several models) based on the last 90 days of completed workouts or using a custom date range.

✅ Stress Score. Intervals.icu uses the term ‘Training Stress Score’ (TSS) and can calculate a power-based TSS for each completed workout.

✅ Stress Balance. Intervals.icu uses the term ‘Form’ to show the balance between ‘Fitness’ and ‘Fatigue’.

✅ Ramp Rate. Intervals.icu shows your week-on-week Ramp Rate (RR), overlaid onto the same chart as fitness, fatigue and form.

✅ Running Effectiveness. Intervals.icu doesn’t calculate Running Effectiveness, although you can manually calculate this using the detailed workout review pages, or by adding a custom calculation.

𝐖𝐡𝐲 𝐮𝐬𝐞 𝐈𝐧𝐭𝐞𝐫𝐯𝐚𝐥𝐬.𝐢𝐜𝐮?

If you’re not using the Stryd ecosystem or TrainingPeaks/WKO, Intervals.icu is a great way to track your power metrics.

‘Getting Started’ covers other apps that can calculate power metrics, while the book’s online content provides a more complete comparison of Intervals.icu vs. other Power Apps.

𝑺𝒉𝒐𝒖𝒍𝒅𝒏’𝒕 𝒚𝒐𝒖 𝒃𝒆 𝑹𝒖𝒏𝒏𝒊𝒏𝒈 𝒘𝒊𝒕𝒉 𝑷𝒐𝒘𝒆𝒓?

❓ Questions?
📖 Getting Started

𝐏𝐨𝐰𝐞𝐫 𝐀𝐩𝐩𝐬 – 𝐖𝐊𝐎

The WKO app is an analysis and charting tool that runs under MS Windows or on a Mac and provides a wide range of charts and graphs of your power data.

It can calculate and display all the most important metrics … and then some.

𝐖𝐊𝐎 𝐌𝐞𝐭𝐫𝐢𝐜𝐬

✅ Threshold Power. WKO uses the term ‘Functional Threshold Power’ (FTP) and offers an automatically calculated FTP, as well as the option to manually record your FTP history (and use it in charts).

✅ Stress Score. WKO uses the term ‘Training Stress Score’ (TSS).

✅ Stress Balance. WKO uses the term ‘Training Stress Balance’ (TSB).

✅ Ramp Rate. WKO can chart your week-on-week Ramp Rate (RR).

✅ Running Effectiveness. WKO can show your Running Effectiveness (RE) for an entire workout or just for part of a workout (e.g. an interval).

𝐖𝐡𝐲 𝐮𝐬𝐞 𝐖𝐊𝐎?

WKO comes with hundreds of pre-configured charts. You can also build your own charts and calculated metrics using a powerful charting language. WKO integrates seamlessly with TrainingPeaks, syncing planned and completed workout data and a range of health metrics.

‘Getting Started’ covers other apps that can calculate power metrics, while the book’s online content provides a more complete comparison of WKO vs. other Power Apps.

𝑺𝒉𝒐𝒖𝒍𝒅𝒏’𝒕 𝒚𝒐𝒖 𝒃𝒆 𝑹𝒖𝒏𝒏𝒊𝒏𝒈 𝒘𝒊𝒕𝒉 𝑷𝒐𝒘𝒆𝒓?

❓ Questions?
📖 Getting Started

𝐏𝐨𝐰𝐞𝐫 𝐀𝐩𝐩𝐬 – 𝐒𝐭𝐫𝐲𝐝 𝐏𝐨𝐰𝐞𝐫𝐂𝐞𝐧𝐭𝐞𝐫 / 𝐒𝐭𝐫𝐲𝐝 𝐌𝐨𝐛𝐢𝐥𝐞

The Stryd PowerCenter / Mobile app is available to anyone using a Stryd footpod (most features are free, some need a subscription).

It calculates and displays some (but not all) of the most important metrics.

𝐒𝐭𝐫𝐲𝐝 𝐌𝐞𝐭𝐫𝐢𝐜𝐬

In the following, the term ‘Stryd’ includes Stryd PowerCenter and Stryd Mobile

✅ Threshold Power. Stryd uses the term ‘Critical Power’ (CP) and offers an automatically calculated CP (Auto-CP) as well as a manually-set CP (using various protocols).

✅ Stress Score. Stryd uses the term ‘Running Stress Score’ (RSS) and offers a unique calculation which includes a term representing the additional biomechanical stress put on your body from running (vs. cycling).

✅ Stress Balance. Stryd uses the term ‘Running Stress Balance’ (RSB) and offers guidance for how to interpret your RSB.

❌ Ramp Rate. Stryd does not show your Ramp Rate (RR). You’ll need to calculate RR manually using Stryd’s 42d Avg (in Stryd Mobile) or use another system to track this.

❌ Running Effectiveness. Stryd does not show your Running Effectiveness (RE). You’ll need to calculate RE manually using another system, or use one of Stryd’s alternate metrics – for example Form Power, Leg Spring Stiffness, Impact Loading Rate.

𝐖𝐡𝐲 𝐮𝐬𝐞 𝐒𝐭𝐫𝐲𝐝 𝐏𝐨𝐰𝐞𝐫𝐂𝐞𝐧𝐭𝐫𝐞 / 𝐌𝐨𝐛𝐢𝐥𝐞?

The Stryd ecosystem is probably the most power-friendly app at the moment, designed with power in mind, and aimed at runners who are getting started with power.

‘Getting Started’ covers systems that can calculate the missing metrics, while the book’s online content provides a more complete comparison of Stryd vs. other Power Apps.

𝑺𝒉𝒐𝒖𝒍𝒅𝒏’𝒕 𝒚𝒐𝒖 𝒃𝒆 𝑹𝒖𝒏𝒏𝒊𝒏𝒈 𝒘𝒊𝒕𝒉 𝑷𝒐𝒘𝒆𝒓?

❓ Questions?
📖 Getting Started

𝐂𝐡𝐨𝐨𝐬𝐢𝐧𝐠 𝐩𝐨𝐰𝐞𝐫 𝐚𝐩𝐩𝐬

Power is a complete system using effort as its fundamental metric.

Power uses your second-by-second effort from completed workouts to calculate metrics that build a detailed picture of your individual running capabilities.

Imagine you run 3 times per week for around an hour each time. That’s 60 pieces of data per minute, 3600 per hour and over 3 runs, over 10,000 pieces of data. That’s a lot of data!

Which is why power relies on power-aware applications (‘apps’) to calculate your metrics.

𝐂𝐚𝐧 𝐲𝐨𝐮 𝐮𝐬𝐞 𝐚𝐧𝐲 𝐚𝐩𝐩?

The choice is yours, but some apps are more power-aware than others, with the best apps able to calculate the most important metrics.

𝐖𝐡𝐢𝐜𝐡 𝐦𝐞𝐭𝐫𝐢𝐜𝐬 𝐚𝐫𝐞 𝐦𝐨𝐬𝐭 𝐢𝐦𝐩𝐨𝐫𝐭𝐚𝐧𝐭?

✅ Threshold Power. Represents your current running fitness.

✅ Stress Score. A score (per workout) that combines ‘how hard?’ and ‘how long?’ to represent the workout’s metabolic stress – its impact on your body.

✅ Stress Balance. Indicates whether your training is ‘productive’  – enough stress to encourage adaptations, but not so much that there is a greater risk of injury or over-training.

✅ Ramp Rate. Replaces ‘the 10% rule’ with a metric based on your training volume and intensity, to monitor whether you’re adding training load too quickly.

✅ Running Effectiveness. Measures how effectively you convert power into speed, used to estimate finish times, to assess changes to your running form and to evaluate your fatigue resistance.

There are other criteria that will influence your choice of apps, but being able to obtain these metrics may be the most important.

𝑺𝒉𝒐𝒖𝒍𝒅𝒏’𝒕 𝒚𝒐𝒖 𝒃𝒆 𝑹𝒖𝒏𝒏𝒊𝒏𝒈 𝒘𝒊𝒕𝒉 𝑷𝒐𝒘𝒆𝒓?

❓ Questions?
📖 Getting Started

𝐆𝐞𝐭𝐭𝐢𝐧𝐠 𝐒𝐭𝐚𝐫𝐭𝐞𝐝

Power is a complete system using effort as its fundamental metric.

So how do you get started?

𝐄𝐪𝐮𝐢𝐩𝐦𝐞𝐧𝐭 & 𝐀𝐩𝐩𝐥𝐢𝐜𝐚𝐭𝐢𝐨𝐧𝐬 (𝐚𝐩𝐩𝐬)

At a minimum you’ll need a power meter, but there are a few other choices you’ll need to make and the options are not independent.

Making a choice in one area almost always affects another, but the primary choice is your power meter.

𝐇𝐨𝐰 𝐝𝐨 𝐲𝐨𝐮 𝐜𝐡𝐨𝐨𝐬𝐞?

The following are some of the criteria you might consider (each bullet indicates whether the Stryd Footpod 🦶 or wrist-based power 👋 has the advantage)

🦶 Can you use any running watch?

Stryd works with many older watches; Wrist-based power is only found in newer watches.

👋 Do you need to buy a separate power meter?

Wrist-based power meters are built into your running watch; The Stryd footpod is a separate purchase.

🦶 Is it easy to obtain power metrics from supporting apps?

The Stryd ecosystem provides most of the key metrics; There’s no ecosystem for wrist-based power (you’ll need multiple apps).

🦶 Has the power meter been independently validated?

There have been at least 10 independent studies validating Stryd’s power numbers; I’m not aware of any independent studies for wrist-based power aside from my own (N=1).

🦶 Can you easily use power on a treadmill, or in GPS-poor areas?

Stryd provides power numbers without needing GPS; Wrist-based watches need GPS to provide power numbers (Garmin is the exception, but is Garmin Power valid on a Treadmill?)

𝐑𝐮𝐧𝐧𝐢𝐧𝐠 𝐰𝐢𝐭𝐡 𝐏𝐨𝐰𝐞𝐫 – 𝐆𝐞𝐭𝐭𝐢𝐧𝐠 𝐒𝐭𝐚𝐫𝐭𝐞𝐝

The book provides a more complete comparison and detailed information on how to get started with power, using a Stryd footpod or wrist-based power.

𝑺𝒉𝒐𝒖𝒍𝒅𝒏’𝒕 𝒚𝒐𝒖 𝒃𝒆 𝑹𝒖𝒏𝒏𝒊𝒏𝒈 𝒘𝒊𝒕𝒉 𝑷𝒐𝒘𝒆𝒓?

❓ Questions?
📖 Getting Started

𝐑𝐚𝐜𝐢𝐧𝐠 𝐲𝐨𝐮𝐫 𝐩𝐞𝐫𝐬𝐨𝐧𝐚𝐥 𝐛𝐞𝐬𝐭

A truth: power isn’t a guarantee that you’ll run a Personal Best (PB) at every race.

So what does ‘racing your personal best’ mean?

𝐏𝐨𝐰𝐞𝐫 𝐢𝐬 𝐩𝐞𝐫𝐬𝐨𝐧𝐚𝐥

It’s a system of metrics based on you as you are right now – your ability, your current fitness, your current form.

Your power metrics are calculated from your completed workouts (for better or worse).

From what you’re able to do.

Right Now.

👉🏼 Power is Personal.

𝐑𝐚𝐜𝐢𝐧𝐠 𝐲𝐨𝐮𝐫 𝐛𝐞𝐬𝐭

If it’s personal to you, how does that translate into racing your best?

Power enables identification of your current running fitness – your Threshold Power.

👉🏼 Which means you’re starting from a known position.

It bases your training targets on your Threshold Power, with incremental progressions (in volume or intensity) to improve your fitness while minimising injury risk.

👉🏼 Which means you can focus on consistently completing planned workouts.

It provides metrics to monitor your changing fitness and your training load, based on your Threshold Power and your completed workouts.

👉🏼 Which means you can adjust your plan if needed (rather than blindly following it).

It uses your training load metrics to plan your taper (more on that in a future post).

👉🏼 Which means you minimise missed training and arrive at the start line with fresh legs, ready to run.

It bases your race day power target on your most recent metrics

👉🏼 Which means you’re running based on you – your race-day fitness, ability, and form.

Power provides a complete system that prepares you to race your best – the rest, as they say, is up to you.

𝑺𝒉𝒐𝒖𝒍𝒅𝒏’𝒕 𝒚𝒐𝒖 𝒃𝒆 𝑹𝒖𝒏𝒏𝒊𝒏𝒈 𝒘𝒊𝒕𝒉 𝑷𝒐𝒘𝒆𝒓?

❓ Questions?
📖 Getting Started

𝐌𝐚𝐱𝐢𝐦𝐢𝐬𝐢𝐧𝐠 𝐲𝐨𝐮𝐫 𝐭𝐫𝐚𝐢𝐧𝐢𝐧𝐠

Your training begins with a goal.

Your goal should translate into a plan for the workouts you’ll run, including target intensities and durations for each.

And then while executing your plan, you should:
🔹 monitor your fitness – to confirm improvements
🔹 monitor your training load – to ensure you maximise training benefits and minimise injury risk

How does power support this approach?

𝐖𝐨𝐫𝐤𝐨𝐮𝐭 𝐭𝐚𝐫𝐠𝐞𝐭 𝐢𝐧𝐭𝐞𝐧𝐬𝐢𝐭𝐢𝐞𝐬

Power enables more precise training targets, using targets relative to your Threshold Power – your current fitness.

Which means:
✅ power targets are clearer than pace or HR targets – just ‘run to the numbers’
✅ you’re more likely to target the adaptations needed for your goal race
✅ as your fitness improves, your targets automatically adjust to match your increased capability

𝐌𝐨𝐧𝐢𝐭𝐨𝐫𝐢𝐧𝐠 𝐲𝐨𝐮𝐫 𝐟𝐢𝐭𝐧𝐞𝐬𝐬

This is as simple as monitoring:
✅ your Power-Duration Curve – improvements should move your PDC up, to the right, or both
✅ your Threshold Power – which, for many runners, will increase as you get fitter

𝐌𝐨𝐧𝐢𝐭𝐨𝐫𝐢𝐧𝐠 𝐲𝐨𝐮𝐫 𝐭𝐫𝐚𝐢𝐧𝐢𝐧𝐠 𝐥𝐨𝐚𝐝

Power provides three key metrics (based on completed or planned workouts) to monitor your training load:
✅ Stress Balance – indicating whether your training is productive.
✅ Ramp Rate – to avoid adding training load too quickly.
✅ Training Intensity Distribution – to check that your training intensity mix matches your goal race.

Power provides a complete system for maximising your training.

𝑺𝒉𝒐𝒖𝒍𝒅𝒏’𝒕 𝒚𝒐𝒖 𝒃𝒆 𝑹𝒖𝒏𝒏𝒊𝒏𝒈 𝒘𝒊𝒕𝒉 𝑷𝒐𝒘𝒆𝒓?

❓ Questions?
📖 Getting Started

𝐓𝐡𝐞𝐫𝐞’𝐬 𝐦𝐚𝐠𝐢𝐜 𝐢𝐧 𝐭𝐡𝐞 𝐧𝐮𝐦𝐛𝐞𝐫𝐬

⚡ Second-by-second as you run, power provides numbers representing your effort.

Why’s that important?

Once you can measure your effort, you can answer all sorts of questions.

Here’s a sample …

… 𝐡𝐨𝐰 𝐟𝐢𝐭 𝐚𝐦 𝐈?

Your Threshold Power is a key measure of your current running fitness.

It’s used to set training targets, to monitor training load, and to set race/event goals.

… 𝐚𝐫𝐞 𝐦𝐲 𝐭𝐫𝐚𝐢𝐧𝐢𝐧𝐠 𝐭𝐚𝐫𝐠𝐞𝐭𝐬 𝐜𝐨𝐫𝐫𝐞𝐜𝐭?

Your training targets are based on your Threshold Power (your running fitness) – what you can achieve right now.

They ensure your targets are ‘just right’ for you, and they self-adjust when your Threshold Power changes.

… 𝐡𝐨𝐰 𝐡𝐚𝐫𝐝 𝐰𝐚𝐬 𝐭𝐡𝐚𝐭 𝐰𝐨𝐫𝐤𝐨𝐮𝐭?

Stress Scores combine ‘how hard?’ and ‘how long?’ for each completed workout.

They represent the workout’s metabolic stress – its impact on your body.

… 𝐚𝐦 𝐈 𝐭𝐫𝐚𝐢𝐧𝐢𝐧𝐠 𝐭𝐨𝐨 𝐦𝐮𝐜𝐡? 𝐭𝐨𝐨 𝐥𝐢𝐭𝐭𝐥𝐞?

Your Stress Balance, calculated from your Stress Scores, shows whether your training is ‘productive’ – not too much, not too little.

… 𝐚𝐦 𝐈 𝐫𝐚𝐦𝐩𝐢𝐧𝐠 𝐮𝐩 𝐭𝐨𝐨 𝐪𝐮𝐢𝐜𝐤𝐥𝐲?

Your Ramp Rate, calculated from your Stress Scores, shows if you’re adding training load too quickly, replacing ‘the 10% rule’ with a metric based on ‘how hard?’ and ‘how long?’

… 𝐡𝐨𝐰 𝐡𝐚𝐫𝐝 𝐬𝐡𝐨𝐮𝐥𝐝 𝐈 𝐫𝐮𝐧 𝐨𝐧 𝐫𝐚𝐜𝐞 𝐝𝐚𝐲?

Race-power planning identifies an effort level you can sustain from start to finish, one that will give you the best result you’re capable of.

… 𝐡𝐨𝐰 𝐜𝐚𝐧 𝐈 𝐫𝐮𝐧 𝐟𝐚𝐬𝐭𝐞𝐫?

By working on your form (how you run), you can improve your Running Effectiveness – how effectively you convert effort into speed.

Running Effectiveness provides an objective way to assess whether form changes are improvements.

All of these metrics are available when Running with Power.

𝑺𝒉𝒐𝒖𝒍𝒅𝒏’𝒕 𝒚𝒐𝒖 𝒃𝒆 𝑹𝒖𝒏𝒏𝒊𝒏𝒈 𝒘𝒊𝒕𝒉 𝑷𝒐𝒘𝒆𝒓?

❓ Questions?
📖 Getting Started

𝐏𝐨𝐰𝐞𝐫 𝐢𝐬 𝐚 𝐜𝐨𝐦𝐩𝐥𝐞𝐭𝐞 𝐬𝐲𝐬𝐭𝐞𝐦

It’s a system built on your individual capabilities.

And it has five fundamental concepts that work together to enable you to run your personal best.

𝐏𝐨𝐰𝐞𝐫 = 𝐄𝐟𝐟𝐨𝐫𝐭

Power represents your effort, so you can see how hard you’re working while running and how that changes as you run (whether you decide to make the change, or hills or wind force you to change your effort).

𝐓𝐡𝐫𝐞𝐬𝐡𝐨𝐥𝐝 𝐏𝐨𝐰𝐞𝐫

Threshold is a small range of effort levels, below which you can run at a steady effort, and above which you fatigue much more quickly and will need to slow down or stop.

Threshold Power is used to set training targets, to monitor training load, and to set race/event goals.

𝐏𝐨𝐰𝐞𝐫-𝐃𝐮𝐫𝐚𝐭𝐢𝐨𝐧

These are inversely related (higher power = shorter duration; lower power = longer duration).

Best effort and maximum effort runs can determine how long you can sustain differing effort levels, giving you a view of your current capability over a range of intensities.

𝐓𝐫𝐚𝐢𝐧𝐢𝐧𝐠 𝐒𝐭𝐫𝐞𝐬𝐬

Stress Scores combine ‘how hard?’ and ‘how long?’ and represent each workout’s metabolic stress – its impact on your body.

You can combine the scores to calculate metrics you can use to monitor whether your training is productive (not too much, not too little), and to manage injury risk.

𝐑𝐮𝐧𝐧𝐢𝐧𝐠 𝐄𝐟𝐟𝐞𝐜𝐭𝐢𝐯𝐞𝐧𝐞𝐬𝐬

A speed:power ratio that you can use to estimate finish times, to assess changes to your running form and to evaluate your fatigue resistance.

𝑺𝒉𝒐𝒖𝒍𝒅𝒏’𝒕 𝒚𝒐𝒖 𝒃𝒆 𝑹𝒖𝒏𝒏𝒊𝒏𝒈 𝒘𝒊𝒕𝒉 𝑷𝒐𝒘𝒆𝒓?

❓ Questions?
📖 Getting Started