Expanding-Lung on the Cheap! Dive Further, Deeper, Longer on One Breath.




Exapanding-Lung is a respiratory training device that retails for $40. This is a similar tool made for less than $10. And can be easily adapted to fit specific mouth sizes and shapes.

Here's what you'll need:

A mouthpiece from an old snorkel or a replacement from a dive shop

A plastic valve that can open and close on a slide, such as a water flow regulator valve for sprinkler systems.

A zip tie or super glue.

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Step 1: The Mouthpiece

If you are a freediver or spearfishing enthusiast then you will know the importance of shaping your mouthpiece to your already existing mouth shape. Working in the opposite order can be painful and timeconsuming, leaving the mouth poorly adept at completing important daily exercises, like eating or making out.

A diver should have a few left over snorkels hanging around the dive bag. Feel free to sacrifice one of these.
Or, it is prudent to visit you dive shop and pick up a replacement mouthpiece, making sure to thoroughly sample each one for that perfect fit.

I find that the LONG BITE works great for my horse face and adequately fits my bursting jowls. Be sure to choose a good mouthpiece because you will have this in your face for at least 30 minutes a day for the rest of your diving life.    

I use Diver's Supply for all my online diving needs. I suggest you do the same.   

Get ready to start doing impressive things like this. 

Step 2: The Valve

The valve is a device that appropriates a restrictive element to a chaotic force (try not to picture a parent leashing their child to their wrist in the Jacksonville (or nearly any other) airport via Monkey-tail leash. Instead, think: dam).

In our case, the valve should be plastic. The lighter the better. And make sure one end is relatively circular.  I browsed the hardware store for nearly 2 hours fitting all types of valves to the pictured mouthpiece and finally settled on the hose adapter. Its light, sturdy and cheap: about 3 bucks.


Step 3: Assembly

No words can adequately describe the intensity of the picture below. Nah, really you just mate the ends of your silicone mouthpiece to the hard plastic "business" end. A generally good rule of thumb: if it doesnt fit right away, keep jamming it in there.


Step 4: Production

You can now secure the mouthpiece with your adhesive or zip tie, and begin to put the Expanding-Lung company out of business. How they ever got to charge 40 bucks a pop for these things is beyond me, like salt lick fine art.

A helpful link.


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9 Discussions


3 years ago

how is this different from breathing in a straw


6 years ago on Introduction

great job , i make it and start using it , but i didnt notice any diffrent yet , only 2 days in use :)
i hope i get better results in few days


6 years ago on Step 4

ooooooh as someone who has NEVER seen anything like this, one thing to be aware of is that there are potentially people who might imagine this is like one of those James Bond underwater breathing gadgets! God forbid that they should try to use it underwater!!!

I realised only by looking at a YouTube review for an Expand-a-Lung that it is an lung exercising gadget.


6 years ago on Introduction

This is great...i built one sort of like this only I used a piece of 1/2 PVC and duct tape over the end to restrict the air flow. It helped with my scuba diving air consumption. I like this better though, easier to adjust


6 years ago on Step 4

In regards to your link to Salt Lick Fine Art I was reading in bewilderment and this quote should say it all haha.

"We'd had a couple of beers, and it just started looking more and more like art to us,"

I had one of those oooOOOOOOOOhhhh moments.


6 years ago on Introduction

Looks easy to make, what are the instructions for use? How to use, how often, how long? How were the results? Have you made it to 4 minutes?

2 replies

Reply 6 years ago on Introduction

Heres how Expand a lung says to exercise. Its a good start. One HUGE note though: Don't use this devise as an exercise enhancer. It should not be used to modify a workout; instead, the breathing IS the exercise.

I am not as loyal to the regimen as I should be. Im at around 2.


6 years ago on Introduction

I don't dive much, but I am a fan of the skilled salt carvings made by livestock tongues.