Breath-Hold Training (Improving CO2, O2, Urge To Breathe) – The Ultimate Guide For Freedivers

One of the essential principles in all sports training is ‘specificity’.

In breath-holding, specificity is primarily a measure of ‘time’ and ‘work rate’, and replicating these things closely will result in steady breath-hold improvement.

In a nutshell, the better job your training does of replicating your goal’s demands (i.e the length of time you need to hold your breath to do your dive), the better and faster it will prepare you for that goal.

Instead of just attempting your target dive repeatedly, a good specific breath-hold exercise incorporates the total dive time into your repetitions, simulating the demands of your target dive.

For example, breath-hold demands can be replicated like this;

- 4:00 STA = 2:00 STA, 1-5 breaths + 1:00 STA, 1-5 breaths, + 1:00 STA.

- 100m DYN = 25s STA + 75m DYN

- 40m CWTb = Hang at 20m for a total dive time of 1:20.

In all three examples, the exercise result is a total breath-hold time that’s the same as what you would expect on the ‘target’ dive.

What makes this helpful training is that these dives/sets will be easier than performing the actual target dive itself. This has two benefits;

1. You can do multiple exercise repetitions, increasing your total training volume.

2. You build ‘dive-time confidence’ since these exercises should feel much easier than the actual performance.

The result? After many repetitions, you’ll teach your nervous system (your subconscious) to accept the dive time. Then, when performing your target dive (and setting your new personal best), the dive(s) won’t feel too long or uncomfortable.

And, who doesn’t want easy, enjoyable, and super comfortable personal best dives?

When it comes to apnea training for dynamic and depth disciplines, it’s also important to consider work rate when thinking about specificity.

What I mean by the term 'work rate' in freediving is the effort and energy you expend on a 'real' target dive.

Your aim in training is to closely replicate that exact work rate to enable you to properly prepare your mind, body and nervous system for the dive you intend to do.

An ineffective way to train would, therefore, be to artificially decrease CO2 production or O2 consumption in training to get the longest dive times possible.

Here are some examples of ineffective training exercises ...

– Target: 100m DYN – A 2:30, 25m super-slow ‘crawl’ along the bottom of the pool

– Target: 40m CWTb – A slow FIM hang at 20m for a 2:00 dive time

Compared to ‘real’ dives, the work rate on these exercises is all wrong.

The diver is only capable of exceeding their ‘expected’ dive time because they are doing significantly less work during these dives, artificially producing less CO2 and consuming less O2.

Yes, these exercises can be fun and enjoyable (which is why they can be done periodically), but they aren’t going to build a solid, goal-specific breath hold.

Write this down, and repeat after me....

To properly prepare for the dive(s) I want to do. I need to perform my training exercises with comparable work rates.

Now, let's put the 'time' and 'work' specific elements together to create an effective training exercise for the example goals above.

Target: 100m DYN

BREATH-HOLD EXERCISE: 25s STA + 75m DYN; the diver will swim the 75m with the exact same technique and effort they’d expect to use on their 100m dive.

Target: 40m CWTb

BREATH-HOLD EXERCISE: 1:20 hang-dive to 20m; the diver should descend to 20m with the same speed, technique (CWTb), and weights as they’d expect to use on a real 40m dive.

By replicating work rates, you can feel confident that your apnea training has properly prepared you for the target dive you intend to do.

And, as you improve, you’ll know these are real improvements caused by increased apnea fitness, NOT artificial improvements caused by simply ‘doing less work’.

If you get your 'specific exercises' right for your apnea training, and you're still struggling with either CO2, O2, Urge to Breathe (or a combination of these!) Likely, you will also need to add in some 'accessory' training to compliment your more 'specific' training.

CO2 accessory exercises are typically short breath-holds with short recoveries (think classic CO2 table).

Their purpose is to elevate and maintain CO2 levels in the body, allowing you to adapt physically and mentally to increased CO2.

BUT ...The most important part of CO2 training is that you do not have any contractions.

Your tables should be designed to allow you to finish each hold just before your first contraction. This will delay the urge to breathe later and later into your dives.

You should build your O2 apnea accessory exercises very similarly to CO2 tolerance training exercises – using short breath-holds with short recoveries. However, you will modify the exercises to do them on either; FRC (passive exhale) or RV (forced exhale).

This change (exhaling) is going to allow you to become safely hypoxic much faster, and hold after hold, you’ll slowly desaturate your blood, maintaining low-level hypoxia for your table.

Usually, you’ll need to increase your recovery times (compared to equivalent CO2 exercises), but if your CO2 tolerance is well developed (and it should be before attempting O2 training!), you should easily be capable of becoming hypoxic on exhale dives without having more than only a mild-urge to breathe.

For advanced divers (or day-1 beginners), learning to deal with the urge to breathe can be a very important part of the sport. Of course, in my opinion, it is much better to delay it completely before working on tolerating the urge to breathe, but for some, it’s the only way to improve.

**for most divers (probably 95%) you’re better off delaying the urge instead of learning to tolerate it. But I’ll share this anyway.

Basically, good ‘urge-to-breathe’ training is going to involve very controlled exposure to this feeling. It can be as simple as performing x-amount of meters or seconds after the urge to breathe starts. Over time, you can increase the amount of time spent with the urge to breathe as you get better and better at tolerating it and staying composed even with this feeling.

As I said at the beginning, breath-hold training is the foundation of all types of freediving.

No matter which discipline or type of diving you’re doing, you’re going to need to hold your breath. Being comfortable with your breath-hold is going to improve all the other aspects of your freediving automatically.

Always remember the most important thing in training is to be ‘specific’.

Also, make sure to identify your main weakness(es) in breath-holding (hint.. For most divers it’s CO2, or they need to delay the urge to breathe)

Using relevant accessory exercises to boost this ‘weak’ area will improve the quality of your ‘specific’ exercises which, in turn, will improve the quality and comfort of your goal dives.

So there you have it, if you follow the guide and take it step-by-step, you’ll actually see a remarked improvement to your breath-hold, and the rest of your freedive training will benefit as a result.

Here’s to being able to freedive for deeper and longer!

Got questions? Drop them in the comments below :)