# Threshold Power & Power Zone Training

Running Power is a measure of real-time effort and the rate of energy being expressed at a given moment. It is typically measured in Watts (W), where higher values correspond with more power being generated.

To bring context to this metric, much like training with Heart Rate, you can run to certain Power Zones to aid your training. For this though, the concept of Threshold Power is needed.

Threshold Power is the average power output that you can hold for a sustained period of time (typically between 30-60 minutes) and is a good indicator of aerobic fitness. To obtain an individualized Threshold Power value, a running test should be completed. Van Dijk and Van Megen suggest that a 10-minute maximum effort run can be enough to determine Threshold Power. NURVV is able to guide you through this 10-minute effort in the NURVV Run App using the “Power Test” workout. To ensure that your Threshold Power is up-to-date and your Power Zones stay relevant to your current level of training we suggest that you run this test every 8-12 weeks.

Your Threshold Power can also be estimated using the table below. Bear in mind that this is a population average equation and to establish the most accurate value of Threshold Power you should run a Power Test via the NURVV app.

1) Identify the best most recent time that you have completed for either a 5 km, 10 km, half marathon, or full marathon.

2) Identify the column for that race.

3) Look down for the time in the table that is as close to your most recent effort.

4) Use the left-most column to identify the Watts per kg for that effort.

5) Multiply this number by your body mass (weight) in Kilograms.

A worked example of this table: a 45 minute 10 km would give you a W/Kg of 3.75. This multiplied by a weight of 75 Kg would give you a Threshold Power of 281 W.

Source: Van Dijk H. & Van Megen R. (2017) Secret of Running: Maximum Performance Gains Through Effective Power Metering and Training Analysis, Meyer & Meyer Sport, 1

Knowing your Threshold Power helps to provide context to the Power metric throughout the app, and also helps you effectively progress in your training. The Threshold Power value is shown on the Power Profile as a horizontal line, this allows you to see what part of your run was above or below your Threshold Power.

Your Threshold Power value allows Power Zones to be determined, much like Heart Rate. See the table below for your Power Training Zones and their benefits.

Running Power Zones

 Power Zone Training Benefit <80% of Threshold Power Zone 1. Relaxed This is a recovery zone, you should complete your warm-up, cool-down and any recovery running that you are doing in this zone 81 – 90% of Threshold Power Zone 2. Easy This is a zone where you can build your aerobic base, it should feel easy and it is a good zone to run your Easy Long run’s in 91-100% of Threshold Power Zone 3. Moderate This zone is a tempo or ‘Threshold’ zone and will start to feel uncomfortable towards the end of a sustained time in this zone 101-120% of Threshold Power Zone 4. Challenging This zone will help build your speed endurance by getting your body to run at an effort above threshold. It is a great zone to do longer interval repetitions in. 121-150% of Threshold Power Zone 5. Hard Zone 5 is great for shorter reps of high intensity; it’ll improve your anaerobic energy system and get your body used to working at greater intensities >151% of Threshold Power Zone 6. Tough This zone is great for max intensity sprints or strides, this high intensity efforts will have neuromuscular benefits such as the ability to recruit more fast-twitch muscle fibres

These Power Zones provide guidance for your running and any workouts that you may choose to do with Power. Therefore, regularly updating your Threshold Power value is beneficial as it will give you the most accurate training zones, and subsequently the best training benefits. If you are stuck on which workouts you can run with Power, check out 5 examples here : 5 Power Workouts