Rating Energy Expenditure in Games is Easier Said Than Done

Measuring energy use while playing games requires you to make a number of assumptions about the player, including how they play, why they play, and how well they play. We strive to be very transparent about our assumptions and our methods so that – if you are inclined – you can challenge, examine, and reference our data without mystery. This page explains the exact methods and needed assumptions that we use for assessing and assigning VR Exercise Ratings.

Assumption No. 01

01. Our users are neither lazy, nor needlessly energetic

We assume that the consumers of our data are interested in exercising. We therefore focus on helping identify high intensity games. We assume that the user will not deliberately avoid movement when playing, but also not deliberately seek it out beyond what the game requires to be successful. We try to apply a reasonable standard for this and measure what we consider to be typical play required to progress through the goals of the game.

Assumption No. 02

02. We assign ratings based on METs, not calories burned

While the badges display estimated calories expended per minute, ratings are actually based on a game’s observed MET score during testing, taking into account the rater’s base metabolic rate during resting. We use calorie estimates for the general user because most people are not familiar with a MET, which is a standard measure of exertion in kinesiology research. Comparisons to other activities, such as tennis, baseball, or boxing, are then based on readily available MET scores for these activities maintained by the US government.

Assumption No. 03

03. We rate peaks & averages

The amount of energy a game burns often depends on player ability. An experienced Audioshield player, for example, can be successful on higher difficulties & will burn more energy as a result. A new player may only be successful on slower settings & will expend less energy in the same game. We record peak sustained METs (highest observed 5-min avg) to help understand what is possible in best circumstances. We record average observed METs over the entire play test to better understand the level of energy expenditure during typical gameplay.

Assumption No. 04

04. We are rating max observed, not max possible

It’s not feasible for our raters to play a game to completion for each rating. They instead attempt to play a representative sample of common gameplay under controlled conditions. This means that we are essentially documenting the highest MET observed during testing. We believe this allows a player to choose a game knowing that it’s been observed to provide at least that level of energy consumption during play. We will almost certainly underrate certain games from time to time, and will be open to adjusting ratings based upon new observations.

Assumption No. 05

05. We will have to rate many games twice

Games are assessed through a combination of oxygen consumption testing and heart rate assessment. A game is assigned a Primary rating based on the heart rate data of a trained subject with a known metabolic baseline, calibrated through metabolic testing. High potential games are then assessed a second time using metabolic carts in the lab to confirm actual observed calorie expenditure directly through oxygen consumption. The results of these metabolic tests not only validate the primary rating, but are also used to maintain rater accuracy.

Assumption No. 06

06. We don’t know the health impact of VR outside energy expenditure

The founding mission of the VR Health Institute is to assess the potential energy expenditure of different VR and AR experiences. While we are interested in all forms of health, we do not have access to any data about other possible effects of long term VR and AR use. Does extended use impact vision health, for example? Are there psychological benefits or concerns from VR use? We don’t know, and make no claims about the global impact of VR on the body. We focus on rating the observed energy expenditure during play.

Always consult your physician before beginning any exercise program. This information is not a replacement for your healthcare professional. Please read our full disclaimer and terms of use.

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