The Ultimate Guide To Freediving, Legal Blood Doping, Wim Hof Breathing, Increasing Your Breathhold Time, Underwater Ear Equalizing, Spearfishing & Much More!

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In my article entitled “How Breath-Holding, Blood-Doping, Shark-Chasing, Free-Diving & Ketosis Can Activate Your Body’s Most Primal Reflex,” I mentioned the fascinating book by James Nestor, entitled “Deep: Freediving, Renegade Science, and What the Ocean Tells Us About Ourselves.”

After reading it two years ago, I hired Ted Harty, from Immersion Freediving in Ft. Lauderdale, Florida, to certify me in freediving so that I could learn how to spearfish.

At over six feet tall and 230 solid pounds, Ted is a big, bold, loud, extroverted character. He looks like a boxer and not like a guy who you’d expect to be diving at incredibly efficient oxygen capacity to depths deeper than most human beings have ever ventured.

But it was Ted who was about to open my eyes to a whole new world of freediving and who I spent nearly every waking moment of ninety-six hours of my life with learning every possible closely-guarded breath-holding and deep-diving tactic.

Ted began his underwater career in 2005 as a scuba instructor in the Florida Keys. Over the years, Ted became a Scuba Schools International Instructor and a Professional Association of Diving Instructors Staff Instructor.

But whenever Ted was on the boat and did not have students to take care of, he’d jump in with mask, fins, and snorkel and play around on the reef, sans scuba equipment. As Ted highlights in this fascinating, quick video about his life:

“Sometimes I’d have just five minutes to swim around without all of my scuba gear. I loved it. I could swim down to the sand at Sombrero Reef and hang out for a bit at 20 feet. I wanted more. I wanted to learn how to stay down longer and how to dive deeper.”

So, in January of 2008, Ted took his first Performance Freediving International (PFI) course.

“I couldn’t believe how little I knew about freediving at the time. As a scuba instructor I knew more about diving physiology than the average Joe, but quickly realized I knew nothing about freediving. At the start of the course I had a 2:15 breath-hold, but after just four days of training, I did a five-minute hold! I couldn’t believe it was possible.”

Next, Ted signed up for instructor-level courses at Performance Freediving. He was soon offered a job teaching with Performance Freediving when he moved to Fort Lauderdale.

Then, in 2009 Ted went to PFI’s annual competition. At the time, he was about an 80- to 90-foot freediver and weighed 230 pounds. He wasn’t in good shape at all, but after three weeks of training under the tutelage of world-renowned freedivers Kirk Krack and Mandy-Rae Cruickshank, he did a 54 meter (177 -feet) freedive.

“I was blown away by what I was capable of.”

Ted spent a year working with Kirk and Mandy while traveling around the country teaching the Intermediate Freediver program. Then, in 2010, a much more fit Ted went back to PFI’s annual competition. That year his new personal best was 213 feet, and currently, he’s managed to up that to an impressive 279 feet.

In June 2012, Ted was selected as the Team Captain for the US Freediving Team at the Freediving World Championships, and in 2013 he attained PFI Advanced Instructor and PFI Instructor Trainer, becoming the first and only PFI independent instructor to receive this rating.

Oh yeah, and Ted also holds the record for hypoxic underwater swimming in the pool, having done 7 full lengths (175 meters) without a single breath. 

But most impressive?

Ted has anemia.

This means his blood can’t deliver oxygen as efficiently to his muscles and brain as most of the world’s population. This means he has a blood hematocrit level of 34, easily 1/3 less than most athletes. This is a condition that would leave most folks huffing and puffing for air after climbing a flight of stairs.

Obviously, anemia hasn’t stopped Ted. In our last podcast, which you can listen to here, Ted and I covered:

-Why being cold and cold water can actually inhibit your ability to hold your breath…

-How to use static apnea tables to enhance your ability to tolerate high levels of CO2 and low levels of O2…

-Why training your mammalian dive reflex is so useful, even if you have zero desire to do long breath-holds or freediving competition…

-Why you should avoid hyperventilation and “blowing off CO2” prior to a breath hold…

-The difference between Ted's breathing techniques and Wim Hof's breathing techniques…

-And much more…

Today Ted is back, and we take a deep dive (pun intended) into:

-What happens to the body during free diving…9:30

  • Similar effects as yoga
  • Alter how you breathe
  • Interact with marine life
  • Stress release

-What the “mammalian dive reflex” is and why we would want to activate it…12:25

  • Genetically coded in every human on the planet
  • Dolphins, seals, whales possess the mammalian dive reflex
  • We all have it, but at different levels depending on experience
  • Several components:
    • Bradycardia; Body lowers demand for oxygen
    • Fingers, toes constrict
    • Pee reflex – peripheral extremities constrict
  • We don't have conclusive data on how free diving affects HRV and the vagus nerve
  • The connection between the spleen and breath holding/free diving
    • Another component of the mammalian dive reflex
    • Simply holding one's breath on dry land compresses the spleen
    • Legal blood doping
    • In elite athletes, holding breath compresses spleen; an ordinary person, not so much
    • In free diving, your body becomes more accustomed to these changes
    • Large amounts of blood circulate through the spleen; compressing it leads to a large release of red blood cells
    • Breath holds in the sauna activate the spleen; not the same effects as diving

-The benefits of free diving…24:37

  • Overall well-being
  • Q: How can drowning and suffocating be relaxing? A: You don't feel that way
  • People swear by its efficacy
  • Comparable to training to lose weight
  • How many calories are lost during free diving:
    • It's absolutely exhausting
    • Generate tremendous amount of body heat
    • Study: 1,100 calories burned per hour
    • Breathwork wouldn't translate to burning calories
    • Glycogen sparing effect
    • Ketones increase the ability to hold breath

-Tips for increasing breath hold time…30:10

  • Take a bigger breath
    • Diaphragm, chest, shoulders, neck
    • Flexibility of rib cage determines the size of your breath
    • “Sipping”

-What an apnea table is and the difference between CO2 and O2 apnea…37:30

  • Table: series of breath holds
    • How you can breathe up for
    • How long you can breathe for
  • Learn to tolerate low levels of oxygen; CO2 levels rising
  • Carbon dioxide table: breath up for 2 minutes; hold breath for 2 minutes…
  • Wonka table
    • You want higher CO2 levels
    • Hyperventilating discards CO2 faster than anything
    • Sit on couch, hold breath
    • You'll feel a contraction, start stopwatch; deal with discomfort for 15 seconds
    • Take one breath
    • Go to the bathroom before doing this!
  • Would you do a table while exercising?
    • No, but you can incorporate breath exercises into your training
    • Risk of blacking out; do on seated equipment
  • Book: The Oxygen Advantage by Patrick McKeown
  • Book: The Power of Your Breath by Anders Olsson

-What kind of breath work one would do in between dives to maintain maximum breath hold time…49:30

  • Remember diaphragmatic breathing
    • Only thing you should feel moving is your stomach moving out and in
    • We're all chest breathers
  • Control, be conscious of your breathing vs. not thinking about it

-Why the Valsalva breathing technique is not optimal for free diving…53:22

  • Pinch and blow: equalize your ears
  • Can use Valsalva scuba diving
  • Frenzel technique
    • Pinch your nose.
    • Fill your mouth up with a little bit of air.
    • Close the epiglottis.
    • Move the soft palate to the neutral position.
    • Use the tongue like a piston and push air towards the back of your throat.
  • Valsalva is optimal for scuba diving as you dive head first; air rises
  • Frenzel is optimal for free diving because you dive head first; opposite of scuba diving

-A demonstration of the Frenzel breathing technique…58:30

-Similarities and differences between Ted's breathing technique and Wim Hof's…1:02:45

  • Hof's methods are good for cold therapy, not necessarily breath holding
  • Hyperventilation increases risk for blackout
    • Drastically lowers CO2 levels
    • Carbon dioxide levels trigger urge to breathe
    • Physically reduces amount of oxygen available to your body
  • Bohr effect:
    • When we hold our breath, our blood becomes more acidic; changes ph levels
    • Hyperventilating increases strength of the bond between hemoglobin and oxygen
    • If strength of bond too high, oxygen molecule can't be used as fuel
  • Hyperventilating initially increases ability to hold breath, but there's the risk of blackout

-Exercise and stretching regimens specific to free divers…1:13:30

  • Paradox: Free divers train a lot, which leads to high metabolism, which you don't want as a free diver
  • There is no set regimen on how to craft the “perfect free diver”
  • Problem seeking to solve is very complicated
  • Similar to training cyclists would undergo
  • Diaphragmatic stretching is critical –
    • Ted gives demonstration

-Some of the courses Ted teaches online…1:26:30

-And Much More…

Click here for the full written transcript of this podcast episode.

Resources from this episode:

Click here to see all of Ted's courses, including how to equalize, how to take a 20-30% bigger breath, how to freedive safely, and much more!

-Deep: Freediving, Renegade Science, and What the Ocean Tells Us about Ourselves

-The OURA ring

The WHOOP wristband

Spleen volume and blood flow response to repeated breath-hold apneas.

CO2 and O2 apnea tables

The Wonka table

-The Oxygen Advantage book by Patrick McKeown

The Power Of Breath

My podcast with Laird Hamilton about underwater workouts

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Do you have questions, thoughts or feedback for Ted or me? Leave your comments below and one of us will reply!

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24 thoughts on “The Ultimate Guide To Freediving, Legal Blood Doping, Wim Hof Breathing, Increasing Your Breathhold Time, Underwater Ear Equalizing, Spearfishing & Much More!

  1. Rich says:

    Hi Ben,

    Are you concerned about any negative effects of freediving?

    Study with conclusion: “These findings suggest that breath-hold diving training over several years may cause mild, but persistent, short-term memory impairments.” on PubMed
    I’m asking because I have done freediving in the past and I’m thinking of getting back into it.



    1. I think this would be more of an issue if you were doing it very regularly. Also if you're using the proper techniques to oxygenate before the breath hold it would seem like less of a concern. Ketones may be helpful for this as well.

      1. Rich says:

        Thanks very much Ben!
        I’m looking forward to starting again with freediving – it’s such a great experience, well done for spreading the word. I’ve only done it in warm water so far, so I want to see what this ‘mammalian dive reflex’ is all about in the cool Atlantic waters!

  2. Robert says:

    What supplement(s) do you recommend for freediving?

    Glycofuse? Any others?

      1. Mikey says:

        Hi Ben by ketones do you mean exogenous?

  3. Ron says:

    So for a breath holding protocol we can do in the sauna, what do you recommend Ben?

      1. Ron says:

        Thanks, will do.

  4. phil heist says:

    Hi Ben do you have any advise for training for high altitude? 21,000 ft

  5. Robert Clark says:

    Both “The Oxygen Advantage” and “The Power of your Breath” seem to have the same views and techniques. Is there value in reading both or do you recommend one over the other to read and to actually put into practice? Thanks!

  6. Robert says:


    We know freediving carries the highest caloric burn at 1,000+ calories per hour, based on your podcast discussion. I’m 6’1”, 165 lbs with extremely low body fat and can’t afford that. If I train for competitive freediving or spearfish for say, at least two hours in the water or more, what blend of supplements would you recommend I take? How often should I take the serving? All at once or spread it out?
    I would assume your previously recommended blend of a 1/2 serving of Glycofuse, and 1 serving of Catalyte electrolytes, Kion Aminos, and ketones/Brain Octane would cover the all the bases for even the lowest body fat/highest metabolisms like mine. So at this point, would you recommend anything different than this blend?

  7. Bryan says:

    Hey Ben, thanks as always for a great podcast. Do the Wonka tables begin by holding an inhalation or after exhalation?

    1. You start recording time when you feel the uncomfortable moment (the first hiccup) as Ted describes it. Check out the show transcript where Ted gives a pretty thorough description:

  8. Christopher Aspinall says:

    I don’t free dive but would like to know if Wim Hof breathing has benefits for the lay man/woman?

  9. GJ says:

    Again awsome episode with ted. Loved it!

    Made very clear to me why not to do wim hof style / hyperventilation breathing before swimming under water Laps.

    The part about under water black out without warning shocked me a little.

    @ben/ted: Is under water blackout a serious scenario when doing some under water Laps after swim training?

    I sometimes push pretty hard (for my standards) to make it to 50mtrs.


    1. Konstantin Kesper says:


      Never freedive unsupervised period.

      Never hyperventillate or use the wim hof method before a dive.

  10. Sam says:

    Hey Ben, I play underwater rugby which basically involves wrestling at depth while holding your breath. What do you think about the training benefit of that given that it combines breath holding with short bouts of intense anaerobic activity?

    1. I would imagine it would be very demanding by combining elements of breath retention, strength and balance, endurance, etc… Sounds fun

  11. Zo says:

    Would using the power lung be a useful tool for becoming a better freediver?

    1. Yes would be helpful.

  12. Kev says:

    Listened to the podcast today while I was out for a run, very interesting to here the amount of calories burnt during the free diving process. I have been looking to learn why I seem to lose so much weight while we are in saturation, but you spoke today about the activation of glycogen caused buy low oxygen levels. We are only breathing 2% o2 mixed with 98% helium while in the system so I wonder if that’s why I lose up to 3/4 kilograms in trip. I’d love to be able to calculate the calories burned in a 6 hour dive but it’s just not possible to wear anything at that depths that would survive a bell run.

  13. gareth thomas says:

    Cool topic & its also popular with those seeking to boost IQ as the diameter of the carotid is supposed to increase

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