Measuring Intensity – Why it is rad and why it sucks

Over the last year I’ve bought in to the power of CrossFit, measuring intensity and the concept of keeping work outs varied, highly intense and functional. I’ve always been a pretty active person but CrossFit has really taken things to the next level.

This post is all about intensity: how to measure it, how I use it, why I use it, why I like it and why it can be a bad way to gauge your improvement.

Measuring intensity of your workouts is awesome for a few reasons. But for those same reasons, measuring intensity can also be a terrible way to decide if you are improving. I’ll explain both below.

What is measuring intensity?

There are a few different ways that intensity is defined. It can be the percentage of perceived effort you are giving during a specific workout. It can be the way you feel during the workout.

For the purpose of this article, I’m talking about the end result of a workout. The calculated power output that comes from the weight you are lifting (including your body weight), the distance you moved it and the time it takes to move it – Foot pounds per second, ft*lb/sec. And I’m also specifically referring to the intensity measurement that is calculated by Beyond the Whiteboard and the system that they use. I know there are other systems out there but the few I’ve seen were very difficult to use.

How I formed an “intense” opinion

I’ve now spent about 20 hours analyzing my workouts from the past year. I’ve compared them in so many different ways that I’m comfortable saying that I know the numbers.

But what I was seeing on paper wasn’t matching up with what I was seeing in myself.

No matter how I rearranged, blocked or scrubbed the data, all of it was leading to the same conclusion – I was exactly the same today as I was a year ago.

OH CRAP! That can’t be! I’ve worked too damn hard.

This is why you have to be careful and make sure you are getting the whole picture.

Why measuring intensity is nerdily cool

Let me be very clear about something so you know where I’m coming from.

I’m a confessed stat geek. I love spreadsheets and regression analysis. Sometimes it is difficult for me to answer the question, “how are you today?” because there are no numbers involved. If I could chart happiness and create a correlation formula, I would (and I’m trying to figure out how).

So you get it. Numbers are good. Lots of numbers are very good.

When I discovered Beyond the Whiteboard my mind was blown. They created a way to document and chart CrossFit workouts that included almost anything. The workouts are boiled down to a single number, intensity. Oh, and all your workouts can be downloaded to a spreadsheet.

These measurements went beyond the typical heart rate monitor and talk test.

In theory, this means that you can compare any workout, regardless of movement or length or weight load and see which one you went harder on.

Did Fran on Monday and Murph on Thursday? How do they measure up to each other? Just compare the intensity numbers and you can see where you worked harder…right?

Not necessarily.

Why it sucks

The problem with comparing a single number (intensity) is that not all workouts are designed to be the same. What I’ve found is that if you just compare the numbers and don’t consider what is going on around it then you are setting yourself up for disappointment. Or at least confusion.

Some basic logic helps this a little. It makes sense that the longer your workout is, the lower your intensity is going to be. It is unreasonable to think that a typical to high level athlete that is going as hard as she or he can go will be able to maintain the same intensity they have in Helen as they do in the Filthy Fifty.

Measuring intensity

Measuring intensity of two workouts that are completely different in time domains does not provide a good comparison.

So if you are going to compare workouts, I believe you have to start with comparing workouts that are similar in their time domain.

But there’s a problem with that, too

Even when you are comparing similar time domains, there are variables that contribute in unknown ways.

  • Workout includes a technical movement? Focusing only technique may slow you down.
  • Had a bad night’s sleep? It could slow you down.
  • Traveled the last two days and couldn’t get in enough calories? Might affect the weight you can move.
  • Yesterday’s workout was brutal and you’re paying for it today? Probably going to slow you down.
  • Injured a knee or your lower back? Makes sense to be more careful.
  • Stressful deadline at work? Your focus may be out of the gym.
  • You are pushed by the class environment but only 1 other person shows up? That may be a factor, too.

You get it. There are a lot of non-quantifiable things going on that can effect your performance.

The right way to use intensity

As I understand it, the measuring of intensity is a relatively new concept in its application here. While measuring pure weight lifting (ie max squat) or simple time measurement (ie 100 meter sprint) has been done for a long time and is pretty self explanatory, the measurement of intensity is just at the beginning.

measuring intensity over the last year

Measuring intensity of workouts from the previous year

With regards to Beyond the Whiteboard, I would love to see how they break down their measurements and see their algorithm, though I’m sure it is proprietary. Through some discussions with others at the gym, it seems to take in to account your body weight and your height in the calculation. You can also enter custom measurements like hip to floor and shoulders to floor.

So the basic measurements are there.

I’m not sure that there is a “right” way to use intensity as described here. We are all different.

But I do believe that intensity is a good way to characterize workouts in a sport as diverse as CrossFit.

I personally use it to get an idea of my performance for a certain time period. Over the last 30 years I’ve learned when my 100% effort is going to be good, great or poor. I also keep that in mind when considering the results.

Additionally, by looking at results that seemed really low, I found weaknesses. And while Beyond the Whiteboard will provide some of this for you (such as overhead strength, read more here), I noticed some things that were not obvious.

For example, when I row for time my intensity is very good. But when I row for calories, my intensity is low.

Or ab work. I always thought my sit ups, GHD and toes to bar were above average, or at least average. Turns out the toes to bar are a bigger limiter than I thought.

This is great stuff and gives me things to work on.

Even though breaking down my results from the last year doesn’t show improvement in my intensity, I can easily look at myself and what I’m now capable and know that I’m better off now than I was 12 months ago. More mobile, stronger, fitter, faster and knowledgeable.

measuring intensity of two time periods

Comparing intensity levels from two time periods interesting. But it is not the whole story.

I absolutely intend to keep using intensity as a tracking metric. But I’m cautious to also track my diet, sleep and overall well being.

The numbers don’t lie. You just have to ask the right question.