Greetings everyone from the team at Science Behind Sweat!! This post has been a long time coming and will hopefully provide you with an adequate update of various features on the site. Recently we’ve made a lot of changes to improve functionality and give people better information on the drivers of their fitness. In particular, we’ve modified work output calculations, developed new analytics (soon to be widely released!), and have added and will be adding a host of other updates and features. Today I’d like to talk about the specifics of our work output calculations so people can better interpret what they’re seeing when they look at their Work Capacity chart and Fitness Scores. Ultimately, we want you to have a full understanding of all of our features and how they feed into our analytics but for now we begin by laying the foundation. So let’s start with calculating work output.
One of the key goals of CrossFit is to maximize an athlete’s ability to do work over broad time and model domains. From a practical standpoint, this could mean anything from shoveling snow off your driveway to battling renegade ninja’s or carrying Uncle Lou to bed after he’s had one too one too many wine spritzers.
How do we take these varying daily activities or exercises like squats, dead-lifts, pull-ups, bosu-ball squats (= terrible idea) and meaningfully quantify them? To do this we have to calculate or at least estimate the amount of work it takes to perform all the movements in each activity or exercise in terms of foot-pounds (ft-lbs) of force. Once all work estimates are calculated for each movement, we can then figure out the total work done.
As an example, let’s take your average statistician (aka, myself).
Build: Height: 6’1”, Weight: 215 lbs.
Workout: Cindy. This is a 20-minute AMRAP (as many rounds as possible); 1 round = 5 pull-ups, 10 push-ups, 15 squats. I have to do as many rounds as I can in 20 minutes.
Work Estimate (per movement):
1 pull-up = 570 ft-lbs x 5 = 2850 ft-lbs
1 push-up = 320 ft-lbs x 10 = 3200 ft-lbs
1 squat = 400 ft-lbs x 15 = 6000 ft-lbs
1 round of Cindy = 12,050 ft-lbs
With my PR (personal record) for Cindy being 27 rounds the total work done is 325,350 ft-lbs or 12,050 ft-lbs x 27.
This feeds into our analytics in two important ways…
1) We can break down activities into key movements and calculate work estimates for a variety of different workouts while also tracking the amount of time it takes to complete a workout.
2) We can plot work output vs. time to get an idea of your ability to do work over broad time and model domains.
In our next post, we’ll talk about the work capacity chart which will draw on some concepts that we discussed in this blog. Please don’t hesitate to provide feedback, post comments on Facebook, or send us an email with any questions.
Remember we are here to help you train smarter!!