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Recording Guidelines for Metric

Setup guidelines for recording video & collecting accurate and reliable barbell velocity data during training

Recording accurate velocity data with Metric

Metric uses computer vision to automatically track barbell velocity from video recorded on your smartphone. This guide covers everything you need to know to capture accurate training data.

How Metric's computer vision works

Computer vision algorithms analyze patterns of light, color, and shapes within video to track objects.

Metric's specialized computer vision system automatically detects and tracks barbells across over 60 exercises, requiring no manual plate target selection or range-of-motion marking. This automation makes the system both more reliable and significantly easier to use than other apps. Because Metric needs no other hardware outside your existing smart phone/table it is much lower friction and more affordable than traditional velocity tracking devices.

Equipment requirements and plate sizing

Metric's tracking system tracks circular weight plates on barbell exercises.

By default it is calibrated for standard 45cm Olympic plates, though you can easily customize this for different plate sizes before starting your recording.

While Metric supports all traditional barbell exercises, trap bar movements, Olympic lifts and their variations, and custom exercises, it's important to note that non-circular equipment like dumbbells or kettlebells aren't currently supported for velocity tracking.

These exercises can still be logged manually in the app.

Video framing guidelines

Recording in Metric is as easy as using any camera app. However, getting reliable data requires following a few basic video setup guidelines.

The key elements to recording for accurate and reliable data are position, framing, lighting, and stability.

Position and framing

For optimal tracking, position your device side on to the barbell. Metric can handle  side-on angles from 0º (directly at the end of the bar) up to 25º forward or back of the barbell.

The height of your device should match your exercise – positioning the device at waist height for most lifts is fine, while raising to chest height for overhead movements will improve reliability when tracking these sets.

Frame your recording to keep the athlete, barbell and plates within the video for the entire set, including setup and rack positions. Move the device closer or further away to achieve this, and If space is limited you can pinch the screen to zoom in or out on the video.

Lighting considerations

Good lighting is crucial for accurate tracking. While Metric can handle various lighting conditions, there are two situations to watch for.

  • Dark plates in dark environments - which makes tracking hard due to a lack of contrast,
  • and bright light sources near the barbell and lifter. Try adjusting your recording angle or switching sides of the barbell to reduce the amount and intensity of these lights in the video frame.

Device stability

For best results mount your device on a tripod or stabilize on a stable surface – any movement of the device during recording will be interpreted as barbell movement, affecting your velocity measurements. Handheld recording is not recommended.

Video import settings

When importing external footage rather than recording directly in the app, use the standard video mode of your devices camera app. Record at HD resolution and 60fps for optimal results.

While 4K video will work, it significantly increases processing time when these large files are imported into Metric. Avoid using specialized recording modes like cinematic or slow-motion, as these can interfere with tracking accuracy.

Submitting bug reports

If you encounter unexpected results, please let us know!

This feedback helps us continuously improve the system's handling of edge cases and unique gym conditions.

You can report issues directly through the set review menu in the app.

Supported devices

At the time of writing Metric VBT is only available on iOS. There is no Android version of the Metric VBT app.

Metric supports iOS 17 and newer and due to the limitations of older Apple camera systems, Metric works best on newer model iPhone or iPad models.

Below is a list of the recommended devices capable of providing accurate velocity data within the Metric VBT app. Devices older than those listed will likely experience extended processing times and potentially inaccurate training data due to lower resolution cameras and less-powerful hardware.

iPhones compatible with Metric VBT:

✅ iPhone 11 and all models newer than this (2019 or newer)

✅ iPhone SE (gen 3+ only)

iPads compatible with Metric VBT:

✅ iPad Pro - forth generation and newer (released 2020)

✅ iPad - 9th edition and later (released 2021)

✅ iPad Air - 2020 edition and later (released 2020)

✅ iPad Mini - 6th edition and later (released 2021)

Devices not capable of running Metric VBT (due to camera or hardware limitations):

⛔️ iPhone XS, XR (these models can work, but expect longer processing times after recording)

⛔️ iPhone 8, 8 Plus, SE (gen 2) and older models (These models have lower quality cameras and limitations in their computer power for running Metric's advanced tracking algorithm - data from these devices may be inaccurate)

⛔️ All iPad models older than those listed above

⛔️ All iPod Touch models

Metric VBT for Android

Metric is currently only available on iOS enabled devices. As a small development team we simply had to prioritise making a great app for one platform instead of a mediocre app for multiple platform, we hope to get Metric up and running on Android in the future.

You can help speed this up by spreading the word and sharing our app with your friends!