Fixed vs Varied Intensity

Why some movements force rest, while others let you slow down and keep moving.

This is a key framework for how I view movement inside the sport of CrossFit, which then influences how I program for it.

A lot of the errors people make when performing workouts comes down to them not knowing the difference between fixed and varied intensity. 

Once you understand the difference, not only will you be able to better approach workouts, your performances will improve as well.

And in order to understand this framework, we are going to need to discuss a few key points to start.

* What intensity actually is

* The difference between sustainable and unsustainable work

* And why fixed vs varied intensity dictates how you should approach a workout


By the end of this episode, you’ll know:

* Why some movements force rest while others don’t

* How elite athletes separate themselves

* And how to apply this framework immediately to training and competition

Here are some resources/papers that were discussed on the episode:

Bernstein, N. A. (1923). Issledovania po biomekhanike udara s pomoshiu svetovoi zapisi (Studies of biomechanics of the strike with the camera recording) [in Russian]. Issledovanija Centr. Instituta Truda 1, 19–79.

Newell, K. M. (1986). Constraints on the Development of Coordination. In M. G. Wade, & H. T. A. Whiting (Eds.), Motor Development in Children: Aspects of Coordination and Control (pp. 341-360)

Enoka RM, Duchateau J. Translating Fatigue to Human Performance. Med Sci Sports Exerc. 2016 Nov;48(11):2228-2238.

Burnley M, Jones AM. Power-duration relationship: Physiology, fatigue, and the limits of human performance. Eur J Sport Sci. 2018 Feb;18(1):1-12.

They are not the same thing.

Training Camp with Coach Sam Smith

Date: October 18-19th

City: Brussels, Belgium 🇧🇪

Location: CrossFit Super7

To register or inquire about further details, send me an email - [email protected]

Link to register - https://buy.stripe.com/4gMdR9blf0Xm6Bc0UU9EI00

Show Note:

1. ​ I referenced the wrong cyclist paper at the end. The correct link and paper is listed below (same authors but slightly different study).

1. ​ ~9 minute mark - another key difference between EIMP and PE, pain will remain present for some time after the work set with EIMP. Whereas with PE, it will instantly begin to drop once you stop performing work. In the former case, the byproducts from the work have shifted the local environment to where pain “sense” will linger for some time. Whereas in the latter case, once you cease working, your brain stops working so hard which starts to drop your PE.

Papers from the episode:

Perception of effort during exercise is independent of afferent feedback from skeletal muscles, heart, and lungs - https://pubmed.ncbi.nlm.nih.gov/18483166/

Central modulation of exercise-induced muscle pain in humans - https://pmc.ncbi.nlm.nih.gov/articles/PMC2375467/

Opioid-mediated muscle afferents inhibit central motor drive and limit peripheral muscle fatigue development in humans - https://pubmed.ncbi.nlm.nih.gov/19015193/

Austin and I discuss weightlifting and his recent visit to Greg Everett’s gym.

Austin and I discuss the value of having a Coach and our personal experience with them.

In this episode, we are going to discuss General vs Specific Adaptations.

A brief overview of the two:

General Adaptations:

Improving central system’s (Pulmonary / Cardiovascular) ability to intake, deliver, and uptake oxygen when performing work.

When you first start training, everything you do is improving this. As you become more trained, the training stimulus must become more “specific” to continue moving the needle.

Specific Adaptations:

Improving specific musculature’s vascular system, mitochondrial and capillary density. You are working to make a specific area more capable.

Come to the training camp!

Link to sign up - https://hrcf.sites.zenplanner.com/event.cfm?eventId=97B4F855-D4CC-4764-BBF7-A6D02CF4218C

In this episode, I discuss 3 distinct exercise thresholds and their application to training.

1. ​ Lactate Threshold
2. ​ Vo2 Max
3. ​ Critical Power/Critical Speed

Papers from the episode:

1. ​ Variability in exercise tolerance and physiological responses to exercise prescribed relative to physiological thresholds and to maximum oxygen uptake - https://pubmed.ncbi.nlm.nih.gov/36710454/

1. ​ Talk Test - https://hrcak.srce.hr/file/284311

1. ​ Power-Duration Relationship: Physiology, fatigue, and the limits of human performance - https://pubmed.ncbi.nlm.nih.gov/27806677/

How to calculate Critical Speed or Critical Power:

Step 1) 

Perform 2 time trial tests in the 3-20 minute time domain (on the same activity)

Running example:

1. ​ 1600m = 5:20
2. ​ 5000m = 19:30

Step 2)

Take Time for Test 2, convert into seconds.

Take Time for Test 1, convert into seconds

1600m = 5:20 = 320 seconds = 3:33/km

5000m = 19:30 = 1170 seconds = 3:54/km

Step 3)

Take Distance 2 and subtract from Distance 1

5000 - 1600m = 3400m

Step 4)

Take Distance delta and divide by Time delta

3400 / 850 = 4:00/km (+/- 5 seconds)

For this individual, their Critical Speed (the name for the value when meters per second is being evaluated) is 4:00/km (+/- 5 seconds) - CS/CP is not too the second specific, it’s a band of time, which is why we want to give about 5 seconds on either side of this value. 

In this episode, Austin and I discuss my summer training camp. Below are more specifics on the camp and how to sign up:

Camp Details:

* Dates: July 26-27th, 2025

* Location: Hudson River Athletics, Hoboken, NJ

* Who Can Attend: Athletes of all ability levels welcome!

What to Expect:

The camp will feature four intensive sessions (two each day) where we'll evaluate and work on:

* Strength assessment

* Muscle endurance

* Work capacity

* Skill development

* Power repeatability

The primary goal of this camp is to provide you with actionable insights about your current fitness level that you can immediately apply to your training program the following week.

Registration:

To secure your spot, please use the link below and enter the discount code when signing up:

Link - https://hrcf.sites.zenplanner.com/event.cfm?eventId=97B4F855-D4CC-4764-BBF7-A6D02CF4218C

If you have any questions about the camp or logistics, please don't hesitate to reach out to me directly.

I look forward to seeing you there!

In this episode, I discuss the following:

Recap the Mayhem Classic

Discuss Competition Fueling Strategies

Review the Mayhem Classic Events

In this episode, I discuss the following:

* The 2025 CrossFit Open workouts

* Length of the events

* Reps and work rates of the events

* Designing intervals to improve performance in the events

* Training considerations based on the events