Evlo Fitness/Education/Body Composition/4 reasons why joint-friendly fitness is also more effective
08/01/2022
4
Dr. Payton Busker, PT, DPT
Dark Mode

4 reasons why joint-friendly fitness is also more effective

Here at Evlo, we are all about joint-friendly fitness. But what exactly does that mean? Today’s post first explains how we define joint-friendly fitness and then dives into the 4 reasons why joint-friendly fitness is actually more effective.

Not all “joint-friendly fitness” is created equal.

Many programs and social media accounts equate “low-impact” with “joint-friendly,” but they are not synonymous entities. 

We define joint-friendly exercises as exercises that specifically target a muscle group without placing unnecessary and potentially damaging stress through the surrounding structures (joints, ligaments, tendons, mensici, etc.). 

We create joint-friendly classes by selecting exercises through a biomechanical lens. We take “good” and “bad” out of the equation, and instead analyze exercises based on 1. how much load is actually going to the muscle group and 2. if said exercise compromises other structures for the sake of muscle activation. 

Oftentimes, compound lifts like squats, overhead presses, etc. fall short in both categories. We will get into the nitty gritty of this below. But it is for this reason that we primarily focus on less complex lifts like step ups, biceps curls, etc. to provide truly joint-friendly classes. 

In addition, some common “low-impact” exercises (like curtsey lunges) can actually place forces through your joints (namely, your knees in this example) that could lead to joint break down over time. So be weary of programs that do not distinguish between the two concepts! 

Speaking of impact, we eliminate the repetitive and compressive nature of a routine solely focused on high intensity interval training (HIIT) by recommending only 1-3 SHORT (think <20 minutes) cardio bursts each week. And we even recommend taking this off of the table if you are actively experiencing joint discomfort or systemic fatigue. This adds to the true joint-friendly nature of our programming! 

But who benefits from a joint-friendly program like Evlo? Is it just for people who have been injured?

The answer is a resounding “NO”. 

Let’s get into the details of why joint-friendly fitness is actually more effective. And why those who are seeking general fitness and well being should switch to it. 

Reason 1: Focusing on single muscle groups with less complex lifts reduces the amount of areas your nervous system has to stabilize. This can lead to better muscular outputs.

In this systematic review, researchers compiled studies to assess which lower body exercise (including step ups, all different squat variations, deadlifts, etc.) produced the highest muscular output to the gluteus maximus. Although most of the exercises achieved some sort of glute max activation, they concluded that all forms of step ups yielded the highest glute max muscular output as compared to all other exercises. 

They did note that step ups can be difficult to perform due to the stabilization requirements at the hip and knee. Here at Evlo, we combat this by placing the contralateral (opposite) hand against a wall. From a biomechanical standpoint, this reduces the unnecessary lateral forces through the working knee and allows for even more specific forces to drive through the gluteus maximus! 

Focusing on single limb activities like step ups as compared to bilateral activities like squats also negates the bilateral deficit phenomenon. This phenomenon suggests that muscular output decreases in each individual limb when both limbs are performing the same action as compared to when one limb is working during an activity.

Reason 2: Each muscle has a unique lever. We can maximize load to an individual muscle group by specifically moving the primary lever.

Compound movements decrease output to each individual muscle group because we are not able to optimize the primary levers’ positions/path of motion for each muscle group involved. 

Let’s compare a front squat variation with a 30 lb dumbbell to a sissy squat with body weight. A sissy squat is performed with heels elevated and knees crossing forward over the toes. 

For a 120 lb individual, force to the quads is illuminated in this rough calculation:

Front Squat:

90 lbs (half of body weight + 30 lb dumbbell) X 3 inches (approximate moment arm to the knee) = 270 lbs X in 

Sissy Squat: 

60 lbs (half of body weight) X 10 inches (approximate moment arm to the knee)= 600 lbs X in 

Due to the external rotation and abduction of the hips in a traditional squat, the moment arm to the knee is significantly reduced as compared to a sissy squat. In addition, the primary lever of the quad (the tibia) is able to reach closer to parallel with the ground in the sissy squat variation. This allows the lever to become more active and therefore place greater load through the quads! 

So although you have more muscle groups working in a traditional squat, you are not maximizing the load you could get to each of those individual muscle groups by choosing different exercises. Learn more about biomechanics here.

Reason 3: Less joint-friendly exercises tend to be more systemically fatiguing. 

Have you ever thought that you need to do endless burpees, jump squats, mountain climbers, etc. to “see results”? Thought “I know my joints hurt, but this is the price I have to pay to achieve my body composition goals” or “since this feels hard, it must mean that I need it”? 

1. You are not alone.

2. I have great news for you. 

“Hard” and “high payoff” aren’t always synonymous when it comes to exercise.

Endless amounts of burpees, jump squats, etc. not only compromise your joint health, but can actually impede motor unit recruitment within individual muscles. This decreases the effectiveness of said exercises for the purposes of muscle growth!

This impediment in motor unit recruitment occurs due to central fatigue. Central fatigue is fatigue stemming from the brain and spinal cord. This feels more like that “all over” feeling of exhaustion that you might experience after a long HIIT workout. 

In order to move the needle with muscle hypertrophy, we are looking to achieve peripheral fatigue. This is fatigue at the site of the muscle stemming from an accurate activation of motor units within the muscle itself. 

Although the two cannot be fully separated, excessive amounts of central fatigue greatly interferes with achieving peripheral fatigue. When you are systemically fatigued, neural drive decreases to the individual muscle groups, limiting the amount of motor unit recruitment that is possible. 

We recommend 1-3, <20 minute HIIT sessions per week only IF your joints are feeling good. This allows us to maximize the benefits of HIIT training (improved cardiovascular health, HRV, etc) while limiting significant joint compression and hypertrophic interference secondary to central fatigue.

Excessive high-intensity or high-impact exercises can also lead to lingering joint inflammation. Inflammation within the joint decreases joint proprioception (your brain’s ability to identify where the joint is in space) and can dampen muscular outputs.  

The brain can interpret decreased joint proprioception as a threat. 

This can lead to a restriction of both mobility and muscular output in order to “protect” the involved joint. Again, decreased muscular output or connection between the motor neuron and the muscle will hinder us from achieving the strongest muscular contractions with each exercise!

Reason 4: You are able to stay more consistent when exercises feel good and when you are not constantly sidelined by injuries. When you select exercises that feel good for your body and do not place unnecessary stress on the joints, you can decrease your risk of overuse injuries.

The tried and true way to achieve muscle hypertrophy is to progressively overload your tissues. If you consistently show up to these joint-friendly lifts and slowly progress the load to the muscles, you will see muscle growth. 

Choosing exercises you enjoy has even been shown to improve body composition results. In a  recent randomized controlled trial, researchers found that participants who were allowed to self-select exercises (choose exercises they preferred) exhibited a greater increase in lean body mass as compared to the participants that were given a particular set of exercises! 

We often hear members say that Evlo is the first program that they have actually enjoyed consistently showing up for. This consistency allows our members to sustainably build muscle without burning themselves out. 

In addition to burnout, overuse injuries can hinder your ability to consistently show up in your workouts.

As I mentioned in the introduction, a program that is full of “low-impact” moves is not necessarily a joint-friendly program. Although you are not contending with the systemic difficulties that can come with a HIIT program, you can still develop joint injuries over time from that type of programming. 

Let’s take a look at a specific exercise that could be considered “low-impact”, but is not necessarily joint-friendly: the curtsey lunge.

A curtsey lunge is performed by crossing one leg behind the other as you hinge at your hip joint. It can be performed with or without additional weight. This exercise is “low-impact” because no jumping or significant joint compression is performed. 

However, this exercise places a rotational force through the knee which causes a significant force on the menisci of the working knee. The knee is a hinge joint that primarily flexes and extends. Overtime, this type of repetitive, loaded rotational force could wear down the menisci of the working knee as it is not designed to consistently account for this rotational load. It is a lot more difficult to show up to your routine when your body doesn’t feel good!! 

You may be thinking “But don’t our knees rotate sometimes in our day to day lives or when we are doing recreational activities like playing soccer with my kids? Shouldn’t I train myself to be ready for those types of movements?”
We believe in building strong muscles to better support our joints without the repetitive wear-and-tear in these loaded situations. That way, when we encounter a situation where we need to utilize the extra cushion/support from structures like the menisci, we have both the muscular and intact connective tissue to handle it!

Joint-friendly fitness is not just for those who have been injured.

It is through consistency with our joint-friendly routines that we can achieve lasting results that we are able to sustain for a lifetime. 

There is no finish line here. But we can “keep ourselves in the race” by treating our bodies with respect and choosing the most joint-friendly (and effective!!) exercises possible.

References

Systematic Review: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7039033/ 

Physics of Resistance Exercise: https://acsmstore.org/the-physics-of-resistance-exercise/
Effect of choosing exercises you enjoy: https://pubmed.ncbi.nlm.nih.gov/29016481/#:~:text=De%20Souza%2C%20EO.-,Auto%2Dregulated%20exercise%20selection%20training%20regimen%20produces%20small%20increases%20in,exercise%20selection%20(AES)%20vs