Dynamic Diaphragm Function Principle 42

Why I Believe Diaphragm Function Is One of the Most Overlooked Keys to Athletic Performance in Repeated Sprint Ability Sports

Over the past 15 years, I’ve noticed a consistent pattern with athletes entering our program from many different training backgrounds. One thing many of them have in common is dysfunctional breathing.

One of the first things we monitor is resting heart rate and how quickly athletes recover between training intervals. Athletes coming from programs that heavily emphasize “bracing the core” often arrive with elevated resting heart rates and much slower recovery between efforts. Then something interesting happens.

Within the first few weeks of our program, and often within the first month, their resting heart rates commonly decrease by 10 to 20 beats per minute. Their heart rates also recover much faster between repeated sprint efforts and high-intensity intervals.

At first, I assumed these improvements were simply the result of better conditioning within the training/lifting program itself. Certainly, our training plays a role. But after seeing this pattern repeat itself, case by case, I became convinced there was another major factor involved.

That factor is diaphragm function.

While I’ve seen this most dramatically in athletes, the same breathing dysfunction shows up in anyone under chronic stress, whether they ever set foot on a field or not.

The Cost of Constant Core Bracing

There is no question that the body must brace during heavy lifting, sprinting, jumping, collisions, and explosive athletic movements. The ability to create stiffness when necessary is essential for performance.

The problem occurs when athletes are taught to keep their core braced all the time.

When the abdominal wall remains chronically tense, it limits the diaphragm’s ability to move through its full range of motion. Instead of breathing deeply into the lower rib cage and abdomen, athletes begin relying on shallow chest breathing using the neck and accessory breathing muscles.

Over time, this changes much more than breathing.

A restricted diaphragm reduces the pressure changes inside the chest that normally assist venous blood return from the lower body back to the heart. When venous return becomes less efficient, the heart often has to work harder to circulate blood throughout the body. One possible consequence is a higher resting heart rate and slower recovery following exercise.

I’ve seen this pattern repeatedly in athletes entering our program.

Why the Diaphragm Matters So Much

The diaphragm is much more than a breathing muscle.

It is one of the body’s primary pumps.

Every diaphragmatic breath creates pressure changes between the chest and abdominal cavities. These pressure changes help move venous blood from the legs and abdomen back toward the heart. They also assist the movement of lymphatic fluid throughout the body.

Unlike the cardiovascular system, the lymphatic system has no central pump. It depends heavily on muscle contractions and pressure changes generated by breathing.

When the diaphragm moves freely:

• Venous blood returns to the heart more efficiently.
• Lymphatic fluid circulates more effectively.
• Tissue swelling is reduced.
• Waste products are removed more efficiently.
• Oxygen delivery improves.
• Recovery is enhanced.

When diaphragm movement becomes restricted, all of these systems may become less efficient.

The Connection to Reflexive Performance Reset (RPR)

One of the biggest changes I’ve seen with Reflexive Performance Reset (RPR) is its ability to reduce unnecessary muscular tension throughout the body.

The diaphragm reset, psoas reset, breathing reset, and spinal resets appear to restore normal movement throughout the entire trunk.

As tension decreases, breathing becomes deeper and more efficient.

I’ve watched athletes who initially believed they had “poor conditioning” suddenly recover dramatically faster between intervals after only restoring proper breathing mechanics.

Many of these athletes tell me they feel like they suddenly got into much better shape.

In reality, they may not have increased their aerobic capacity overnight.

Instead, they’ve simply removed the restrictions that prevented them from using the cardiovascular and respiratory systems they already possessed.

Heart Rate and Heart Rate Variability Tells the Story

One of the most consistent physiological changes we’ve observed after implementing daily RPR is improvement in Heart Rate Variability (HRV).

HRV is one of the best indicators of autonomic nervous system balance.

When the diaphragm is functioning properly and breathing mechanics improve, athletes often shift toward greater parasympathetic activity — the recovery side of the nervous system.

The result is often:

• Lower resting heart rate
• Faster heart-rate recovery
• Improved HRV
• Better sleep
• Reduced muscle tone
• Greater recovery between training sessions

These improvements frequently occur before significant changes in aerobic fitness would be expected, suggesting that restoring breathing mechanics may play a major role in improving recovery.

Recovery Between Repeated Sprints

In repeated sprint sports like hockey, football, soccer, basketball, lacrosse, rugby, and many others, one of the greatest performance indicators isn’t simply how high your heart rate gets.

It’s how quickly it comes back down.

Athletes who recover faster between efforts are able to produce high-speed movements more consistently throughout competition.

If your nervous system remains locked in a high sympathetic state because your breathing mechanics are dysfunctional, every sprint costs more.

Every recovery period becomes less efficient.

Over the course of an entire game, that difference becomes enormous.

This is one reason I believe diaphragm function deserves far more attention in athletic development.

The Goal Isn’t Less Stability — It’s Better Control

None of this means athletes should never brace.

Elite athletes absolutely need the ability to create tremendous trunk stiffness when force demands it.

The key is having the ability to alternate between stiffness and relaxation.

Brace when force production requires it.

Relax when it doesn’t.

The best athletes don’t stay rigid.

They transition seamlessly between stability, mobility, and recovery.

That is exactly what we’ve tried to teach through Reflexive Performance Reset.

By restoring diaphragm function, reducing unnecessary muscular tension, and improving breathing mechanics, we’ve consistently seen athletes lower resting heart rates, improve heart rate variability, recover faster between intervals, and ultimately sustain higher levels of performance throughout competition.

After watching thousands of athletes over the past decade and a half, I no longer believe better conditioning alone explains these changes.

I believe one of the most overlooked performance tools in sports today is restoring the body’s ability to breathe the way it was designed to breathe.