Freediving - Breathlessly Deep on a Deep Breath
This past weekend I had the opportunity to participate in a sport that is quickly gaining popularity among today's athletes, and is truly without parallel in the sporting world. I'm talking about freediving, which is the sport of underwater breath-hold diving, used in spearfishing, snorkeling, underwater photography, or pure recreation.
The sport involves a basic contradiction: athletic activity usually involves high consumption of oxygen, while diving underwater necessarily requires conservation of oxygen, for lack of a scuba tank. Finding the balance between these opposing factors is part of what makes the sport so fascinating. In fact, taking the course felt like becoming a superhero; all these amazing abilties to hold my breath, to dive deeper than I ever thought possible, considering that I had been barely able to touch the bottom of my grandparents' swimming pool growing up.
Unlike most any other sport, the pace of record-breaking in freediving is actually accelerating. Of sixteen competitive categories recognized by the sport (eight men's, eight women's), thirteen have seen new world records in the past year alone.
I had signed up for a four-day intermediate-level course with Performance Freediving Inc., run by Kirk Krack and Mandy-Rae Cruickshank, both world-class freedivers. Mandy has held several world records, and it's no exaggeration to say that she gives dolphins a run for their money. Also assisting was Craig Gentry, a member of the USA national freediving team.
The course was hosted by Malibu Divers, a scuba outfit I've dived with extensively. The owner, Carter, was kind enough to arrange the course, and another Malibu Divers regular, Matt, joined me for the four-day training session. Matt have never really free-dived before, so the sport was totally new to him; I've had some amount of experience with breath-hold diving while snorkeling, but never any formal training.
Day 1: Apnea
The course began with several hours of classwork: learning the physiology and safety aspects of the sport. Learning about the Mammalian Diving Reflex; why hyperventilation is counterproductive; the signs and symptoms of hypoxia and blackout; rescue techniques for emergencies; proper breathing techniques to slow your metabolism; and how to build up your CO2 tolerance and maximize breath-hold time.
Later in the afternoon we headed over to the Pepperdine swimming pool, where we slithered into our custom form-fitting wetsuits (an awkward endeavor, requiring several dollops of hair-conditioner to expedite the way), ultra-low-profile freediving masks, rubber weight belts, and extra-long fins. An hour of rescue drills, how to handle an unconscious or semi-conscious diver, how to protect the airway, how to make someone start breathing again. Matt and I took turns rescuing each other in simulated situations, until we got the hang of it.
Then it was over to the shallow end, for static apnea (breath-holding). Two minutes of controlled breathing (quick inhale, hold for two seconds, slow exhale for ten seconds, hold two seconds, repeat), followed by a one-minute breath-hold. Piece of cake. Then a three-minute breathe-up, followed by five "purges" (deep inhale, four-second deep exhale), and a two-minute breath-hold. Easy. Then a four-minute breathe-up, five purges, and a three-minute breath-hold. I had done this before, so I didn't have much difficulty, but some of my classmates were starting to struggle. Finally, a five-minute breathe-up, five purges, and a four-minute-max breath-hold. I was completely in the zone, and spent the first few minutes nearly asleep, eyes closed, just floating. Periodically Matt would give me two taps, and I'd signal that I was still doing fine. As four minutes approached, I started to feel a slight urge to breathe, but didn't want to up yet. I heard Craig say: "You're making this look way too easy; go for 4:15." As that time approached, I slowly planted my feet, grabbed the edge of the pool, and at 4:20 lifted my head out of the water. Six quick breaths, an "okay" signal, and within a few seconds I felt completely back to normal. According to Kirk, this breath-hold time theoretically corresponds to over a 200-foot dive (taking exertion into account), so I was stoked! My personal bests are 5:30 for breath-holding and a 60-foot dive, so I was eager to get into the ocean and put my training into practice.
Day 2: Heat
Alas, the ocean would have to wait one more day. Day 2 consisted of more classroom and pool training, focusing on stretching exercises and negative compression, getting used to the feeling of 100 feet of water compressing your lungs and chest. The standard training maneuver: bend over and exhale as much air as you can, then stand up straight and suck in your diaphragm, compressing your chest and lungs. This typically triggers an urge to breathe, even though you have plenty of oxygen; the stretching helps to overcome this reflex. It also helps diminish the residual lung volume, making more air available for equalization during a deep dive. The second training maneuver was to breathe all the way out, then sink to the bottom of the 16-foot pool, simulating the chest compression of a 200-foot dive. We learned to use our throat muscles to make "grouper call" sounds, using the throat as a piston to force bits of remaining air up from our lungs, enabling equalization at depth. An odd and uncomfortable sensation at first, but increasingly more comfortable as we got used to it.
Unfortunately, this day found us in the middle of a heat wave, wearing thick wetsuits in a heated pool with the sun straight overhead, and pretty soon we were suffering from the heat. (I hadn't gotten much sleep the night before, either.) After more rescue practice, we headed over to the shallow end for another static-apnea attempt. I wasn't feeling nearly as good as the day before, possibly fighting off a cold, but I gamely went through the preparation exercises: a five-minute facial immersion to stimulate the diving reflex and slow the metabolism, then a three-minute breathe-up, and a two-minute breath-hold. Comfortable, but not effortless. Then a four-minute breathe-up, and a three-minute breath-hold. The day before this had been trivial, but this time I was starting to overheat; I felt the urge to breathe around 2:45, and knew I was nowhere near my best performance. Finally, a five-minute breathe-up, and a maximum breath-hold attempt. I started feeling the CO2 buildup in my lungs around 3:30, and by four minutes I was struggling. My diaphragm started going into periodic involuntary contractions, a typical and expected symptom of extended breath-holds; uncomfortable, but not painful. I also got a bit self-conscious, since I had never done this in front of anyone before. By 4:30 the contractions were getting intense, and I was losing my willpower, so I stood up. Six quick breaths, ok signal, but I was feeling pretty wiped out.
Astoundingly, one of our classmates was a 60-year-old spearfisherman and triathlete, who managed to pull out a six-minute breath-hold, approaching the elite level. He came up smiling, to cheers and applause. Another classmate made 4:45 but blacked out momentarily on surfacing, definitely making the highlights reel. Within seconds he was fine; competitive freedivers regularly lose consciousness, with no persistent ill effects. (Note: I have little desire to become a competitive freediver; I'm doing this for recreation!)
After the pool session we raced down to Long Beach to catch the Catalina ferry, making it by minutes. An uneventful crossing, a big spaghetti dinner, and a good night's sleep to prepare for the next day!
Day 3: Depth
Woke up early, bright and sunny, and went off to eat a light breakfast. Sixteen of us in a kitschy Catalina pancake house, all ordering oatmeal with raisins and no coffee, all added up to a very confused server. An hour later, we walked up to Casino Point, and swam out a couple hundred yards to the dive floats, in 100 feet of water. I was still feeling a bit out of sorts, but the sun was out, the surface water temperature about 66 degrees, and I felt comfortable enough in the water. I floated at the surface, letting my black wetsuit soak up the sun's rays.
After a five-minute facial immersion to kick-start the dive reflex, we took turns pullling ourselves down a line, hanging underwater until we felt the urge to breathe, then coming up. We started at 5 meters, then went to 10, 15, and 20 meters. A wicked thermocline at 50 feet dropped the water temperature to 55 shivering degrees, but I wasn't down there that long. With the dive reflex, even at 60 feet with my lungs compressed, I felt totally fine; staying underwater for a minute and a half on each dive. Then we went through some rescue scenarios, learned the techniques for finning up and down instead of pulling on the line, and headed back to shore for lunch and a rest.
Later in the afternoon, back out for more diving. After some preparatory dives, the line was lowered to 80 feet, and after a breathe-up I started back down. Kick hard down to 33 feet, then softer down to 66 feet, then drift deeper as negative buoyancy kicks in.The difference between 60 and 80 feet was night and day; I felt serious compression on my lungs, and had difficulty finding air to equalize, using the grouper-call technique to get air. Yet I never felt out of breath, and hung on the line for several seconds at 80 feet acclimatizing to the pressure, before slowly swimming back up, streamlined with hands overhead. Drop hands at 33 feet, exhale halfway at six feet, then on hitting the surface, take a deep breath and hold for three seconds; breathe out and in quickly; hold three seconds; out and in, hold. Then three quick breaths to blow off the last CO2, and an okay signal.
Still feeling good, I decided to attempt a 100-foot dive. Breathe-up, take a huge breath, and dive down. Strong kicks to 33 feet, soft kicks to 66, then drift down. I was able to equalize to about 90 feet, then stretched to reach the plate at the bottom of the line. Tap, turn, kick back up. And up. And up. And up. Whew! My dive watch read 95 feet; over 50% deeper than my personal best. After a ten-minute break, I tried one more time, and reached 96 feet. Then a few more rescue exercises, and we called it a day.
Day 4: Cold
Woke up with a slight fever; probably the same cold I'd been fighting all week. Low-energy, and not enough time to eat a proper breakfast; half a power bar, collected my stuff together, and we walked out to the dock to catch the King Neptune, a dive boat that would carry us out to the deep water site. 15 minute boat trip, then we slithered into our cold wetsuits, donned the gear, and jumped in the water. I was still feeling under the weather, but really didn't want to miss the opportunity. The weather itself was also under the weather; cloudy and cold, with some wind blowing. We started with the five-minute facial immersion, lowering our metabolism; within a few minutes, I was shivering. I should have been smart and headed back to the boat; more on that soon.
We went through the pull-downs to 5 meters, 10 meters, 15 meters, 20 meters, and my shivering was getting intense. The boat was 200 feet away, and no one else was swimming back, so I didn't want to be the first to wimp out. As this was my last opportunity to try a deep dive, and I really wanted to see 100 feet on my watch, I tried to pull myself down the line. Got to 91 feet, couldn't equalize, felt out of breath, so I came back up. Rested a bit, and my shivering began to subside. (Bad sign.) Figured I'd try one last time: Kicked down to 33 feet, 66 feet, drifted down, and got within a few feet of the bottom plate: my watch read 97 feet, but I was already out of breath. The kick back up felt interminable; never any panic, but a long, long swim. Reached the surface, shivered my way through a few last rescues, then we swam back to the boat. By this time I was seriously hypothermic; perhaps 94 degrees core temperature by my best guess, but it didn't occur to me to worry about it.
So we got back on the boat, got out of our wetsuits, and went to the on-boat shower to rinse off. Hot shower. Really, really bad idea. As I discovered afterward, a hot shower is perhaps the worst possible thing I could have done with hypothermia. The heat stimulates the circulation in the limbs, which makes the cold blood stream straight back to the heart and lungs, lowering the core temperature even more. After a few minutes, I started to feel a very peculiar sensation, like my chest and lungs were shivering. I checked my heartbeat, and it was erratic; fluttering randomly between 60 and 120 beats per minute in a chaotic dance. Otherwise I still felt okay, so it didn't seem like an emergency; I just tried to stay warm, and although I was very tired, I didn't feel dangerously bad. The arrhythmia persisted for over an hour, but finally subsided after we ate a hot lunch and walked over to the ferry.
In hindsight, there were several contributing factors, all preventable. I woke up with a fever; that alone should have kept me out of the water. My electrolytes were imbalanced from no breakfast, which can aggravate arrhythmia. After an hour in the water, I was probably a bit dehydrated. And I let myself get way too cold, which is really the wrong time to do strenuous exercise and breath-holding. And finally, the hot shower triggered the further drop in core temperature and resulting arrhythmia.
I'm planning to get an EKG test to be safe; I don't anticipate anything out of the ordinary, but I've never had one before, so it's long overdue. Besides, I'll need a doctor's note to get clearance for the advanced freediving course in Kona this August, which I'm very much looking forward to. I also look forward to writing a blog entry that focuses less on medical mishaps, and more on the beauty of freediving!
Update: Clean bill of health, EKG normal, all systems go. Excellent!
Update 2: Turns out the arrhythmia was nothing but Respiratory Sinus Arrhythmia, which is a perfectly normal occurrence, and actually A Good Thing. From the article: "In humans, the magnitude of the RSA increases with physical conditioning and self-induced, relaxed breathing. RSA becomes less prominent with age, diabetes and cardiovascular disease."
And here is a Class Video !
The sport involves a basic contradiction: athletic activity usually involves high consumption of oxygen, while diving underwater necessarily requires conservation of oxygen, for lack of a scuba tank. Finding the balance between these opposing factors is part of what makes the sport so fascinating. In fact, taking the course felt like becoming a superhero; all these amazing abilties to hold my breath, to dive deeper than I ever thought possible, considering that I had been barely able to touch the bottom of my grandparents' swimming pool growing up.
Unlike most any other sport, the pace of record-breaking in freediving is actually accelerating. Of sixteen competitive categories recognized by the sport (eight men's, eight women's), thirteen have seen new world records in the past year alone.
I had signed up for a four-day intermediate-level course with Performance Freediving Inc., run by Kirk Krack and Mandy-Rae Cruickshank, both world-class freedivers. Mandy has held several world records, and it's no exaggeration to say that she gives dolphins a run for their money. Also assisting was Craig Gentry, a member of the USA national freediving team.
The course was hosted by Malibu Divers, a scuba outfit I've dived with extensively. The owner, Carter, was kind enough to arrange the course, and another Malibu Divers regular, Matt, joined me for the four-day training session. Matt have never really free-dived before, so the sport was totally new to him; I've had some amount of experience with breath-hold diving while snorkeling, but never any formal training.
Day 1: Apnea
The course began with several hours of classwork: learning the physiology and safety aspects of the sport. Learning about the Mammalian Diving Reflex; why hyperventilation is counterproductive; the signs and symptoms of hypoxia and blackout; rescue techniques for emergencies; proper breathing techniques to slow your metabolism; and how to build up your CO2 tolerance and maximize breath-hold time.
Later in the afternoon we headed over to the Pepperdine swimming pool, where we slithered into our custom form-fitting wetsuits (an awkward endeavor, requiring several dollops of hair-conditioner to expedite the way), ultra-low-profile freediving masks, rubber weight belts, and extra-long fins. An hour of rescue drills, how to handle an unconscious or semi-conscious diver, how to protect the airway, how to make someone start breathing again. Matt and I took turns rescuing each other in simulated situations, until we got the hang of it.
Then it was over to the shallow end, for static apnea (breath-holding). Two minutes of controlled breathing (quick inhale, hold for two seconds, slow exhale for ten seconds, hold two seconds, repeat), followed by a one-minute breath-hold. Piece of cake. Then a three-minute breathe-up, followed by five "purges" (deep inhale, four-second deep exhale), and a two-minute breath-hold. Easy. Then a four-minute breathe-up, five purges, and a three-minute breath-hold. I had done this before, so I didn't have much difficulty, but some of my classmates were starting to struggle. Finally, a five-minute breathe-up, five purges, and a four-minute-max breath-hold. I was completely in the zone, and spent the first few minutes nearly asleep, eyes closed, just floating. Periodically Matt would give me two taps, and I'd signal that I was still doing fine. As four minutes approached, I started to feel a slight urge to breathe, but didn't want to up yet. I heard Craig say: "You're making this look way too easy; go for 4:15." As that time approached, I slowly planted my feet, grabbed the edge of the pool, and at 4:20 lifted my head out of the water. Six quick breaths, an "okay" signal, and within a few seconds I felt completely back to normal. According to Kirk, this breath-hold time theoretically corresponds to over a 200-foot dive (taking exertion into account), so I was stoked! My personal bests are 5:30 for breath-holding and a 60-foot dive, so I was eager to get into the ocean and put my training into practice.
Day 2: Heat
Alas, the ocean would have to wait one more day. Day 2 consisted of more classroom and pool training, focusing on stretching exercises and negative compression, getting used to the feeling of 100 feet of water compressing your lungs and chest. The standard training maneuver: bend over and exhale as much air as you can, then stand up straight and suck in your diaphragm, compressing your chest and lungs. This typically triggers an urge to breathe, even though you have plenty of oxygen; the stretching helps to overcome this reflex. It also helps diminish the residual lung volume, making more air available for equalization during a deep dive. The second training maneuver was to breathe all the way out, then sink to the bottom of the 16-foot pool, simulating the chest compression of a 200-foot dive. We learned to use our throat muscles to make "grouper call" sounds, using the throat as a piston to force bits of remaining air up from our lungs, enabling equalization at depth. An odd and uncomfortable sensation at first, but increasingly more comfortable as we got used to it.
Unfortunately, this day found us in the middle of a heat wave, wearing thick wetsuits in a heated pool with the sun straight overhead, and pretty soon we were suffering from the heat. (I hadn't gotten much sleep the night before, either.) After more rescue practice, we headed over to the shallow end for another static-apnea attempt. I wasn't feeling nearly as good as the day before, possibly fighting off a cold, but I gamely went through the preparation exercises: a five-minute facial immersion to stimulate the diving reflex and slow the metabolism, then a three-minute breathe-up, and a two-minute breath-hold. Comfortable, but not effortless. Then a four-minute breathe-up, and a three-minute breath-hold. The day before this had been trivial, but this time I was starting to overheat; I felt the urge to breathe around 2:45, and knew I was nowhere near my best performance. Finally, a five-minute breathe-up, and a maximum breath-hold attempt. I started feeling the CO2 buildup in my lungs around 3:30, and by four minutes I was struggling. My diaphragm started going into periodic involuntary contractions, a typical and expected symptom of extended breath-holds; uncomfortable, but not painful. I also got a bit self-conscious, since I had never done this in front of anyone before. By 4:30 the contractions were getting intense, and I was losing my willpower, so I stood up. Six quick breaths, ok signal, but I was feeling pretty wiped out.
Astoundingly, one of our classmates was a 60-year-old spearfisherman and triathlete, who managed to pull out a six-minute breath-hold, approaching the elite level. He came up smiling, to cheers and applause. Another classmate made 4:45 but blacked out momentarily on surfacing, definitely making the highlights reel. Within seconds he was fine; competitive freedivers regularly lose consciousness, with no persistent ill effects. (Note: I have little desire to become a competitive freediver; I'm doing this for recreation!)
After the pool session we raced down to Long Beach to catch the Catalina ferry, making it by minutes. An uneventful crossing, a big spaghetti dinner, and a good night's sleep to prepare for the next day!
Day 3: Depth
Woke up early, bright and sunny, and went off to eat a light breakfast. Sixteen of us in a kitschy Catalina pancake house, all ordering oatmeal with raisins and no coffee, all added up to a very confused server. An hour later, we walked up to Casino Point, and swam out a couple hundred yards to the dive floats, in 100 feet of water. I was still feeling a bit out of sorts, but the sun was out, the surface water temperature about 66 degrees, and I felt comfortable enough in the water. I floated at the surface, letting my black wetsuit soak up the sun's rays.
After a five-minute facial immersion to kick-start the dive reflex, we took turns pullling ourselves down a line, hanging underwater until we felt the urge to breathe, then coming up. We started at 5 meters, then went to 10, 15, and 20 meters. A wicked thermocline at 50 feet dropped the water temperature to 55 shivering degrees, but I wasn't down there that long. With the dive reflex, even at 60 feet with my lungs compressed, I felt totally fine; staying underwater for a minute and a half on each dive. Then we went through some rescue scenarios, learned the techniques for finning up and down instead of pulling on the line, and headed back to shore for lunch and a rest.
Later in the afternoon, back out for more diving. After some preparatory dives, the line was lowered to 80 feet, and after a breathe-up I started back down. Kick hard down to 33 feet, then softer down to 66 feet, then drift deeper as negative buoyancy kicks in.The difference between 60 and 80 feet was night and day; I felt serious compression on my lungs, and had difficulty finding air to equalize, using the grouper-call technique to get air. Yet I never felt out of breath, and hung on the line for several seconds at 80 feet acclimatizing to the pressure, before slowly swimming back up, streamlined with hands overhead. Drop hands at 33 feet, exhale halfway at six feet, then on hitting the surface, take a deep breath and hold for three seconds; breathe out and in quickly; hold three seconds; out and in, hold. Then three quick breaths to blow off the last CO2, and an okay signal.
Still feeling good, I decided to attempt a 100-foot dive. Breathe-up, take a huge breath, and dive down. Strong kicks to 33 feet, soft kicks to 66, then drift down. I was able to equalize to about 90 feet, then stretched to reach the plate at the bottom of the line. Tap, turn, kick back up. And up. And up. And up. Whew! My dive watch read 95 feet; over 50% deeper than my personal best. After a ten-minute break, I tried one more time, and reached 96 feet. Then a few more rescue exercises, and we called it a day.
Day 4: Cold
Woke up with a slight fever; probably the same cold I'd been fighting all week. Low-energy, and not enough time to eat a proper breakfast; half a power bar, collected my stuff together, and we walked out to the dock to catch the King Neptune, a dive boat that would carry us out to the deep water site. 15 minute boat trip, then we slithered into our cold wetsuits, donned the gear, and jumped in the water. I was still feeling under the weather, but really didn't want to miss the opportunity. The weather itself was also under the weather; cloudy and cold, with some wind blowing. We started with the five-minute facial immersion, lowering our metabolism; within a few minutes, I was shivering. I should have been smart and headed back to the boat; more on that soon.
We went through the pull-downs to 5 meters, 10 meters, 15 meters, 20 meters, and my shivering was getting intense. The boat was 200 feet away, and no one else was swimming back, so I didn't want to be the first to wimp out. As this was my last opportunity to try a deep dive, and I really wanted to see 100 feet on my watch, I tried to pull myself down the line. Got to 91 feet, couldn't equalize, felt out of breath, so I came back up. Rested a bit, and my shivering began to subside. (Bad sign.) Figured I'd try one last time: Kicked down to 33 feet, 66 feet, drifted down, and got within a few feet of the bottom plate: my watch read 97 feet, but I was already out of breath. The kick back up felt interminable; never any panic, but a long, long swim. Reached the surface, shivered my way through a few last rescues, then we swam back to the boat. By this time I was seriously hypothermic; perhaps 94 degrees core temperature by my best guess, but it didn't occur to me to worry about it.
So we got back on the boat, got out of our wetsuits, and went to the on-boat shower to rinse off. Hot shower. Really, really bad idea. As I discovered afterward, a hot shower is perhaps the worst possible thing I could have done with hypothermia. The heat stimulates the circulation in the limbs, which makes the cold blood stream straight back to the heart and lungs, lowering the core temperature even more. After a few minutes, I started to feel a very peculiar sensation, like my chest and lungs were shivering. I checked my heartbeat, and it was erratic; fluttering randomly between 60 and 120 beats per minute in a chaotic dance. Otherwise I still felt okay, so it didn't seem like an emergency; I just tried to stay warm, and although I was very tired, I didn't feel dangerously bad. The arrhythmia persisted for over an hour, but finally subsided after we ate a hot lunch and walked over to the ferry.
In hindsight, there were several contributing factors, all preventable. I woke up with a fever; that alone should have kept me out of the water. My electrolytes were imbalanced from no breakfast, which can aggravate arrhythmia. After an hour in the water, I was probably a bit dehydrated. And I let myself get way too cold, which is really the wrong time to do strenuous exercise and breath-holding. And finally, the hot shower triggered the further drop in core temperature and resulting arrhythmia.
I'm planning to get an EKG test to be safe; I don't anticipate anything out of the ordinary, but I've never had one before, so it's long overdue. Besides, I'll need a doctor's note to get clearance for the advanced freediving course in Kona this August, which I'm very much looking forward to. I also look forward to writing a blog entry that focuses less on medical mishaps, and more on the beauty of freediving!
Update: Clean bill of health, EKG normal, all systems go. Excellent!
Update 2: Turns out the arrhythmia was nothing but Respiratory Sinus Arrhythmia, which is a perfectly normal occurrence, and actually A Good Thing. From the article: "In humans, the magnitude of the RSA increases with physical conditioning and self-induced, relaxed breathing. RSA becomes less prominent with age, diabetes and cardiovascular disease."
And here is a Class Video !
posted by Ben Weiss at
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