Depth Adaptation with FRC Freediving Training and RV Diving

Understanding FRC and RV Training in Freediving

In the world of freediving, Functional Residual Capacity (FRC) and Residual Volume (RV) training have emerged as powerful techniques for those looking to master deep dives and train for extreme pressure adaptation. These methods allow freedivers to simulate the intense conditions of deep-water dives without needing to fully inflate their lungs, making them excellent training tools for equalization and safe pressure handling at shallower depths.

Exploring FRC Diving in Freediving

Freediving is an incredible journey of self-discovery, focus, and endurance under the sea. As freedivers progress, they search for new techniques to refine their skills and push limits. FRC diving, or diving on a partially-filled lung, is one of those techniques designed to help divers simulate the physiological demands of depth without needing to travel to greater depths. This makes FRC training particularly useful for divers who don’t have easy access to deep-water training locations or want to practice without high physical strain.

What Exactly is FRC Diving?

In FRC diving, freedivers exhale partially before diving, filling their lungs to about 50-70% capacity—compared to full lung diving, where the diver breathes in completely to maximize oxygen storage. For an average adult, this means FRC diving involves using about 2.5-3 liters of lung volume, whereas full-lung dives typically involve 5-6 liters. This difference in air volume allows freedivers to simulate the effects of depth on their body without actually diving as deep.

FRC diving is a technique that helps freedivers develop strength and adaptability for deep dives. By diving with a lower lung volume, the diver’s body experiences the physiological sensations of a greater depth, but from a safer, shallower position.

Want to learn more about adapting to deep diving? Explore our Freediving and the Mammalian Dive Reflex article to see how your body’s natural reflexes help you manage underwater pressure.

Why FRC Training Matters in Freediving

FRC training allows freedivers to strengthen both their mental and physical abilities for depth without the strain of a full descent. This technique has become especially popular among freedivers aiming to fine-tune their skills for high-pressure conditions and master their equalization.

Freediving legend Umberto Pelizzari emphasizes the benefits of FRC training. According to Pelizzari, training with reduced lung capacity mimics deeper depths and provides the diver with valuable insights into their body’s responses to pressure changes. In his words, “FRC training is invaluable in helping freedivers understand and prepare for the physical and mental demands of deep diving. This kind of training cultivates control and confidence, which are key to succeeding in freediving.”

My Personal Insights on FRC Training

Having practiced FRC diving extensively, I can attest that it’s a challenging yet rewarding approach to freediving. FRC dives allow me to replicate deep dive conditions, even in limited-depth environments. On an FRC dive, my body feels as if I’m at three times the depth compared to a full-lung dive. For example, starting an FRC dive at around 20 meters creates pressure effects similar to a full-lung dive at 50 meters. This aspect of FRC diving means I can build my pressure tolerance at shallower depths with the safety of a buddy nearby.

Each FRC dive requires mental resilience, as starting with less air can trick your mind into feeling the urge to breathe earlier. But over time, FRC training strengthens both your mind and body, preparing you for the next depth challenge.

For more on handling the urge to breathe and finding relaxation under pressure, check out How to Control Your Urge to Breathe.

Introducing RV Diving: A Technique for Simulated Depth

In addition to FRC, RV (Residual Volume) diving is another powerful technique used by advanced freedivers. RV diving involves exhaling completely—emptying the lungs as much as possible—before starting the dive. The goal of RV diving is to simulate intense underwater pressure right from the surface, creating a deep dive effect at a safe, shallow depth.

This intense technique requires full exhalation to reduce the lungs to only their residual volume, usually about 20-25% of full lung capacity. For the average male diver, this would equate to approximately 1.5 liters, with volume decreasing further under pressure. This means an RV dive to 10 meters mimics the pressure felt at 60 meters with full lungs, allowing freedivers to train for deep dive conditions without going beyond a safe depth.

To read more about maintaining lung health and flexibility, explore The Anatomy of Freediving, which dives into how lung capacity impacts your ability to handle deep-water pressure.

Expert Opinions on RV Training in Freediving

RV training has been praised for its unique benefits by freediving veteran Aharon Solomons. Solomons believes that RV diving is an incredibly effective training tool for enhancing both physiological and mental resilience in freediving. He advocates that RV dives are even safer than FRC dives since the pressure is simulated from the start and at a shallower depth.

Solomons notes that RV diving encourages physiological adaptations, like blood shift, more rapidly than FRC. Blood shift refers to the movement of blood toward essential organs under pressure, which helps safeguard the lungs and body during dives. Solomons also highlights that RV dives are typically shorter, as the diver is starting with minimal air, reducing overall exposure to pressure and enhancing safety.

“RV diving,” Solomons says, “not only strengthens the body but also challenges the diver’s mental fortitude. It’s a mental game as much as a physical one, pushing freedivers to refine their focus, control, and adaptability at depth.”

Pressure	Depth	Lung Volume (Full Lung)	Lung Volume (FRC)
1 bar	0m	6 liters	3 liters
2 bar	10m	3 liters	1.5 liters
3 bar	20m	2 liters	1 liter
4 bar	30m	1.5 liter	0.75 liters
5 bar	40m	1.2 liters	0.6 liters
6 bar	50m	1 liter	0.5 liters

My RV Training Experience: Taking Freediving to New Depths

When I began training with RV dives, I quickly realized it was a next-level experience. Compared to FRC, RV diving required a much higher degree of mental control as I was diving on an empty lung. From the start, you feel the chest pressure, the need to equalize is immediate, and the mental discipline required is intense. RV dives challenge you to manage every sensation while adjusting to depth at a safe, shallow distance from your buoy and safety diver.

Both FRC and RV dives have helped me build adaptability and lung flexibility, and have provided me with a better understanding of depth and pressure adaptation. I’ve gained invaluable insights into how to handle intense conditions with safety and calm, taking my freediving training to a new level.

FRC and RV Training Safety: Staying Safe and Informed

It’s important to emphasize that FRC and RV training should be done with caution. Both techniques simulate intense pressure changes, which requires understanding of your own limits and proper technique. Experts like Pelizzari and Solomons encourage a gradual approach to both types of training, underscoring that freedivers should progress at their own pace with experienced instructors or diving buddies.

With proper guidance and care, FRC and RV training can deepen your skills as a freediver, improve your body’s resilience to pressure, and strengthen your mental focus underwater.

For more on building resilience and mental control, take a look at Freediving Techniques for Better Sleep, where we explore breath-based methods to calm your mind.