Nicholas Rolnick, The Human Performance Mechanic

Nicholas Rolnick, The Human Performance Mechanic Certified Strength and Conditioning Specialist (CSCS)
Doctor of Physical Therapy
Learning and growin

Physical Therapist
Strength and Conditioning
Personal Training
Optimizing Movement
Brookbush Institute Author
Adjunct Faculty for Concordia University-Chicago teaching Kinesiology
"The Human Performance Mechanic"

06/18/2026

This was a hard one to update in my own teaching. Metabolic stress was one of the three pillars of hypertrophy I learned in school. In Episode 5, Paul Carter walks through three consecutive studies that have killed the hypothesis. Lactate infusion in humans, mechanical overload in rodents, in vitro experiments with myotubes. No hypertrophic response in any of them. Metabolic stress was theorized but never proven, and the recent body of research has buried it. But academia hasn't caught up yet.

Full episode: https://www.youtube.com/watch?v=JNth7TPorSs

06/18/2026

The exercise is a posterior pelvic tilt…

06/16/2026

This is one of those studies that gets cited constantly in BFR research, and when you actually read the methods, the design falls apart. The 2012 Nielsen paper had the BFR group training to failure, but the control group was work-matched, not effort-matched. That means the control group was nowhere near failure. Of course the BFR group showed dramatic differences, they were exercising in a completely different myocellular environment. I work through it in Episode 5.

Full episode: https://www.youtube.com/watch?v=JNth7TPorSs

06/15/2026

Getting to a level where you are no longer a stiff immobile person is very challenging. Improving takes time and a lot of effort. Months of consistent end range and but the cool thing is that once you’ve achieved the goal mobility, keeping it is VERY easy. Unlike the hours and hours of work it took to get there, you probably only need 5 min max a week to keep most mobile positions. Exposure tells the body to keep it.

So if you’re an immobile stiff person, suffer through it but on the other side it’s rainbows and butterflies.

06/13/2026

This is the cleanest progressive overload framework I use with my clients, and Paul Carter walked through it in Episode 5. Start at 2 to 3 sets per muscle group per session with long rest periods. If they're progressing, don't change anything. Plateau? Add a set. Still plateaued? Add a rest day between sessions. Three rules, one decision at a time. No periodization spreadsheets needed.

Full episode: https://www.youtube.com/watch?v=JNth7TPorSs

06/13/2026

Upper trap training using elevation is stupid. You’re going to give yourself a nice lower cervical injury and become my next patient. And even so, the risk/reward of these are not there for me. Not even mentioning the fact that the do NOT majorly contribute to elevation of the Scapula - they are MAJOR retractors. So row heavy and get yolked without injuring your neck. You’re not even getting that will be meaningful given the limited size of the fibers that could theoretically contribute to the movement versus those that contribute to retractions. Meanwhile, the elevation function is largely through rotation of the clavicle anyways. It’s all a big myth. But please - continue to do so and even do so with such poor form that you crush your lower neck and continue facilitating muscles prone to over activity anyways. This is one of the old that just didn’t stand the test of time. Hard pass on these for anyone. Really. Anyone. If you want to hit upper traps, arms overhead and shrug.

06/12/2026

Two things have been on my mind. Lots of social media awareness about the benefits of low load exercise with or without compared to heavy lifting. I wanted to bring up two points:
1. I think the hypertrophic differences are probably an artifact of a short training period in these studies. It is VERY hard for me to believe that simultaneous recruitment of motor units would underperform motor unit cycling (where some motor units are recruited but not others and then shut off due to fatigue etc.) over a long time horizon. It’s simply LESS efficient. This isn’t even including the fact that we know fatigue is BAD for muscle growth as a concept...meaning fatigue leads to a loss of access of these high threshold motor units. We should strive to continually stimulate these motor units without the negative impacts on fatigue.
2. The psychology of lifting. Pure and simple. it is going to be much easier to motivate nyourself for a set of 6-8 versus a set of 15-30. Now rinse and repeat for thousands of reps. With the physiology of motor unit recruitment (let’s not discount the impact of FATIGUE either), you will need to push consistently into the upper rep ranges with lower weights to even “match” the potentially equal stimulus of heavy lifting. We know that afferent feedback is a way to reduce the recruitment of these high threshold motor units so inevitably at some point you will hit that wall...and maybe not fully stimulate the muscles.

What are your thoughts on this

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