Dean Karnazes: the man who can run for ever

Most runners have to stop when they reach their lactate threshold, but Dean Karnazes’ muscles never tire: he can run for three days and nights without stopping. What’s his secret?

From club runners to Olympians, every athlete has a limit. Scientifically, this limit is defined as the bodys lactate threshold and when you exercise beyond it, running rapidly becomes unpleasant. Weve all experienced that burning feeling heart pounding, lungs gasping for air as your muscles begin to fatigue, eventually locking up altogether as your body shuts down. However, there is one man whose physiological performance defies all convention: Dean Karnazes is an ultrarunner from California and, at times, it seems as if he can run for ever.

Karnazes has completed some of the toughest endurance events on the planet, from a marathon to the South Pole in temperatures of -25C to the legendary Marathon des Sables, but in his entire life he has never experienced any form of muscle burn or cramp, even during runs exceeding 100 miles. It means his only limits are in the mind.

At a certain level of intensity, I do feel like I can go a long way without tiring, he says. No matter how hard I push, my muscles never seize up. Thats kind of a nice thing if I plan to run a long way.

When running, you break down glucose for energy, producing lactate as a byproduct and an additional source of fuel that can also be converted back into energy. However, when you exceed your lactate threshold, your body is no longer able to convert the lactate as rapidly as it is being produced, leading to a buildup of acidity in the muscles. It is your bodys way of telling you when to stop but Karnazes never receives such signals.

To be honest, what eventually happens is that I get sleepy. Ive run through three nights without sleep and the third night of sleepless running was a bit psychotic. I actually experienced bouts of sleep running, where I was falling asleep while in motion, and I just willed myself to keep going.

While supreme willpower is a common trait among ultrarunners, Karnazes first realised that he was actually biologically different when preparing to run 50 marathons in 50 days across the US back in 2006. I was sent to a testing center in Colorado, he recalls. First, they performed an aerobic capacity test in which they found my results consistent with those of other highly trained athletes, but nothing extraordinary. Next, they performed a lactate threshold test. They said the test would take 15 minutes, tops. Finally, after an hour, they stopped the test. They said theyd never seen anything like this before.

As Laurent Messonnier from the University of Savoie explains, the difference is that your aerobic capacity is a measure of your cardiovascular system performance, while your lactate threshold is your ability to clear lactate from your blood and convert it back into energy.

If you take a high-level runner and you train that guy for a long time, his cardiovascular system will improve until a certain point where it will be very difficult to improve it further, as its determined by the heart and the blood vessels. So if you carry on training that guy, you will not improve his aerobic capacity but his performance will still improve, because the lactate threshold is not limited by the cardiovascular system its determined by the quality of the muscles.

Your body clears lactate from the blood via a series of chemical reactions driven by the mitochondria in your muscle cells. These reactions transform lactate back to glucose again and they are enhanced by specific enzymes. The clearance process also works more efficiently if your mitochondria have a larger capacity, increasing their ability to use lactate as a fuel.

Years of training will improve both your enzymes and mitochondria and so improve your clearance, but there is a limit to how much you can improve your lactate threshold by training alone. If you inherit these enzymes and a larger mass of mitochondria genetically, your personal limits will be far higher.

Karnazes fell in love with running from an early age, and at high school he began to show endurance capabilities which far surpassed those of his peers. At one charity fundraiser, while his fellow runners were able to manage 15 laps of the track at most, Karnazes completed 105. But in his mid-teens he stopped altogether until experiencing an epiphany on his 30th birthday. Gripped by a powerful desire to run once more, he set off into the night.

After 15 years of no training, most of us would not have been physically capable of getting too far, but Karnazes did not stop until 30 miles later. Although the blisters were excruciating, his muscles showed little sign of fatigue.

Many elite distance runners will show some improvements in their ability to clear lactic acid from the system due to the training effect, but that only goes so far, he says. The rest, as I am told, is left up to heredity. They say the best thing you can do as a long-distance runner is to choose your parents well!

However, genetics alone does not tell the full story. Karnazes believes that his lactate clearance abilities could also be down to low body fat, low sweat rate, a highly alkaline diet and low exposure to environmental toxins. Genetics can give you the propensity for a natural advantage but you express your genes differently depending on your environment and your lifestyle.

The intriguing question is whether Karnazes lactate clearance abilities would be the same now if he had not done so much running at an early age.

If you take two twins one grows up in Africa and one grows up in northern Europe their athletic performance will potentially be very different, because they will express their genes differently as the environment, food, everything is different, Messonnier says.

An interesting experiment could be to repeat the lactate threshold test with Karnazes brother.

He plays competitive volleyball but has never really done an extensive amount of running, Karnazes says. I would be curious if he exhibits some of those same abilities to clear lactic acid from his system.

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Top 20 Best Cities To Visit When You’re Young, Broke And Adventurous

Traveling the world while in your 20s is possibly one of the most carefreeexperiences that you will ever have. This is not to say that traveling becomes any less enjoyable as you get older; it’s just different.

Now at29, I simplydon’t have the patience to share a dorm with 20 other snoring and highly sexually active backpackers, and I don’thave the stamina to party until the wee hoursof the morning, or the ability to hold down terrible-tasting, cheap shots. Although, come to think of it, I don’t think my younger 20-year-old self possessed that ability either.As you get older, your tastes and priorities change, which is why you should make the most of travel while in your carefree 20s.

Here is a list of20 cities to visit in your 20s, when having that 20s stamina may very well come in handy.

1. Berlin

Berlin radiates “uber” cool and is a magnet for creatives, hipsters and entrepreneurial types. Check out the bars in grittyKreuzberg, explore the industrial buildings in the Urban Spree, cheer on the brave souls atbear pit karaoke inMauerpark and ride a bike along the airstrip at the abandoned Tempelhof airport.

You’ll need all the stamina that you can muster to keep up with this experimental city.

2. Budapest

Budapest hascemented itselfas one of Europe’s coolest cities and for good reason. The glitteringDanube River literallydividesthe city into two, and also figurativelysplits the city’spersonality.

You’ll find the hordes of tourists on the leafy Buda side during the day, and the partygoers on the Pest side in the evening. Stay in the hip Jewish quarter and spend time inthe makeshiftruin pubs born out of abandoned buildings. The original and most famous ruin pub, Szimpla Kert, is a visual feast to behold.

Budapest is also known as the “city of spas,” sohead to one of the infamous spa parties if you’re game.

3. London

A cosmopolitan melting pot of cultures and a hub for excellent music, it is often saidthat London is the centre of the universe, a fact which is indisputable when you’re there.

Join the cool kids for a gin and tonic in the trendy suburbs ofEast London,pick up one-of-a-kind vintage finds at the Portobello Market and watch all ofyour favorite bands for less than 20 quid. The royal family isn’tagainst welcomingcommoners into the regal fold, so you never know

4. Tokyo

Home tothe wacky, bizarre and the brilliant, there is no other city quite as eclectic asTokyo, or one as likely to make you feel as if you’re in a Manga comic.

Pretend you’re one of Gwen Stefani’s backup dancers in quirky Harajuku, have a sak with Japanesesalarymen in one of the minuscule bars in the Golden Gai area, get your geek on in nerd-town Akihabara and, of course, belt out your favorite J-pop tunes inone of the many karaoke bars.

5. New York

It’s cool, urban and trendy, and you’ll need a whole lot of New York swag to keep up with all of the pavement-pounding locals in this concrete jungle.

Findthe pocket of New York that speaks to you: whether it’s the edgy Lower East Side, boho Greenwich Village, trendy Tribeca or hipster-central Brooklyn. Walk the Highline, visit Central Park and soak in the view from the top of the Empire State Building.

You’ve seen the movies, you know what to do.

6. Dubrovnik

Blessed witha mesmerizing locale on the Croatian coast,Dubrovnik is a must-see for all 20-somethings.Although not as renownedas its island counterpartsfor its party atmosphere,there is still plenty to dowithin the ancient city walls of the Old Town, which has its own unique auraof Adriatic charm.

Don’t miss out on the Buza bar, otherwise known as the “hole-in-the-wall,”a bar perched on the cliffs offering uninterrupted panoramas of the sparklingsea. You’ll need to pinch yourself to make sure you’re not dreaming.

7. Amsterdam

A strange combination of refinement and liberalness, Amsterdam is the home of canals and tulips, sex and weed. Although let’s be honest, the young’uns areprobablymore interested in the latter.Twenty-somethings will fall in love with the freedom and autonomy that Amsterdam grants its residents and the unrivaled friendliness of the locals.

8. Rio deJaneiro

There are three certainties in life: death, taxes and that the last one standing during a night out will always be a Brazilian. Seriously, Brazilians know how to party. Time your visit to coincide with the colorful and wonderful Carnival festival that is held annually before Lent.

Otherwise, spend yourdays sun baking on the famous Copacabana and Ipanema beachesbefore practicing your samba moves and drinking caipirinhas to your heart’s content.

9. Phuket

Phuket’s reputation as a party hub is well established. Most of the activity takes place along Bangla Road in Patong, where youwill encounter thecurious and the outlandish among the bright neon lights and discotheques. It’s cheap and cheerful; what more could you want?

10. Hong Kong

More than astopover city, Hong Kong offers the best in food, shopping and entertainment. Gorge on the dumplings at Tim Ho Wan, the cheapest Michelin-starred restaurant in the world, watch the symphony of lights illuminating Victoria Harbour and then head on over toLan Kwai Fong on Hong Kong Island, the centre of HK’s bustling nightlife and a beacon for the expat community.

11. Barcelona

This spirited Spanish city isa wonderful mix of quirkyarchitecture, delectable foodand lively nightlife. Explore Gaudi’s architectural masterpieces during the day (don’t miss the incrediblePark Gell), grab a fresh juice from La Boqueria, settle in for your 9 pm tapas dinner and then find a cool bar tucked away in the labyrinth of the Gothic Quarter where you can get your flamenco on.

12. Las Vegas

Look, I can’t say too much because, you know, what happens in Vegas stays in Vegas. Although I think this line is used just to mask the fact that most people don’t actually rememberwhat happenedafter a weekend away in Vegas. Thisdesert oasis cityis made for partiers and punters, and you will soon find yourself getting seduced by the (faux) glitz and glamour.

13. Buenos Aires

Here is city that will be guaranteed to have you reveling until the early hours of the morning, simply because the parties in Buenos Aires areknown to get started at 2 am hope you’ve had your coffee intake! Buenos Aires is smooth,sexy and intoxicating, and the perfect place to dance the night away beforethe sun comes up.

14. Istanbul

A citywhere east and west collide front-on, Istanbulis a cosmopolitanblend of different cultures and empires. Wake up to the mesmerizing call to prayer at the Blue Mosque (it’s goose bump-worthy), haggle for colorful scarves and carpets at the Grand Bazaar, and visit a hamman for a traditional Turkish bath and a vigorous scrub.

Beyolu is the epicenterofIstanbul’s pulsating nightlife, and you’llfind a diverse mix of people partying together in trendy rooftop bars to more traditional folk venues.

15. New Orleans

Not just the birthplace of jazz, New Orleans is also famed for its raucous and jubilantnightlifeand you will be swept away by the joie de vivre spirit that embodies this city.

Join in on the festivities during Mardi Gras which occurs at the beginning of the year. Otherwise, tuck into thedelicious gumbo, jambalaya and po-boys, enjoy the live music scene onFrenchman Street and hit the bountiful bars on Bourbon Street in the French Quarter.

16. Tel Aviv

Tel Avivis a lively,young city with a beautiful coastline and plenty of vivacious energy to keep you buoyed throughout the night. It’s often touted as the party capital of the Middle East, which may come as a surprise to some, but perhaps it’s the backdrop of ongoing conflict that compels locals to live in the moment and toseek outfun and pleasure.

Head tothe beachfrontif you’re keen toparty by the wateror check out the bars along the area surroundingLilienblum Street if you’re in the mood forsomethingwith a local flavor.

17. Reykjavik

It’s super expensive but oh-so worth every dollar and, in this case, Icelandickrnur.For a city with such a small population, Icelandic people seemed to be iced (pardon the pun) in coolness and creativity.

Icelandersalso know how to have a good time and after spending your daysroad-trippingand marveling at the sublimebeauty of the island, you’ll want to join in on the rntur, which is the town pub crawl.

Taste the local “schnapps” Brennivn, otherwise known as the Black Death.

18. Santorini

Sure there are other Greek Islands better known for their party vibe; however, Santorini undoubtedly wins the award for best-looking. The whitewashed walls of Cycladic housesperched dramatically on the cliffs,contrast brilliantly againstthe indigoAegean sea. This is a vision that will be engrained in your brain for years to come.

19. Melbourne

I may be biased, as it’s my hometown, but Melbourne is simply one of the coolest cities if not the coolest in the world with the best bars, restaurants and coffee on offer in this cosmopolitan microcosm.

All of the action happens down dimly lit laneways, behind dumpsters, in abandoned lofts and through unmarked doors, so you need to be in the know to know where to go. The rule of thumb is to venture down every derelict alleyway that you come across; you never know what you maydiscover.


Bienvenue Montral! As the home to the second largest number of French-speakers outside of France, it may be beneficial to brush up on your high-school French to score points with the locals.

Montral is a captivating city with ajam-packedfestival calendar,innovative culinary sceneand countless cocktail bars topractice your Franaisin.

This post was originally published on the author’s blog.

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