The Science of Distance Running
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The Science of Distance Running


Yup that’s me. You might be wondering how I ended up in this
situation. So I’m training for a marathon. I’m 15 miles into this run. I have another 7 to go. I’m losing steam. My legs are cramping. I can barely breathe. I don’t know if I can make it another mile. What happened? You basically need three things to run a marathon:
energy, oxygen and water. Our bodies mainly use the sugar glucose for
energy. We store it in big blobs called glycogen that
can hold 30,000 glucose molecules. Building up glycogen is the basis for carbo-loading
or carbing up. That’s when runners eat loads of carb-heavy
meals, cramming as much glucose into their cells in the days before a race. Sounds like a great excuse to eat a bunch
of pasta, but studies show it actually does work to increase your energy stores. Runners need oxygen too. First to, you know, live. But second because it’s key to using glucose
efficiently. Our cells use oxygen in the reactions that
break down glucose. Aerobic respiration, which relies on oxygen,
is about 20 times more efficient than anaerobic respiration, which does not use oxygen. Aerobic activity like distance running, cycling,
cross-country skiing has you breathing in a lot to keep going. Anaerobic activity is short & fast, like sprinting
or weight-lifting. Oxygen fuels our body’s breakdown of glucose
to water and carbon dioxide. Training increases the amount of oxygen your
body takes in and your cell’s ability to use it. All that makes for more efficient use of last
night’s pasta. When you start getting out of breath, your
body is falling behind on the cleanup of waste products from burning all that fuel. That can lead to fatigue. As your aerobic respiration rates drop, your
cells can only break glucose in half. That makes lactic acid. It’s a myth that lactic acid leads to muscle
soreness. But the higher acidity inside your cells does
disrupt biological processes. That’s why your brain tells your legs they
are on fire: it wants you to slow down and catch your breath. You can run low on glucose too. Runners like to say they’ve “bonked”
when they run out of glycogen. It tends to happen around mile 20 (about 32
km), which is when many distance runners feel like they hit “the wall.” When that happens, your cells start breaking
down fatty acids make more energy. Endurance athletes who have trained properly
can “break through the wall” more smoothly and keep on truckin’. Hitting the wall unprepared can be dangerous. Breaking down fatty acids form ketones, which
can trip a process that drops your pH and causes dehydration – this tires you out faster. And then there’s water. One of water’s most important functions
is keeping you cool. When you sweat, liquid water on your skin
evaporates, turning into water vapor. The energy that water molecules take into
the gas phase comes from your body’s heat. That’s how sweating cools you off – it literally
pulls heat away from your body. Sweat also gets rid of salts. When we’re glistening heavily we can run
low on salts, which is why sports drinks contain sodium chloride, calcium chloride, potassium
phosphate and other salts, AKA electrolytes. Yup, electrolytes are just salts. It is possible to drink too much water. When you drink more than you’re sweating
out, it can lead to hyponatremia, a dangerously low sodium concentration in your blood that
can cause your brain to swell. Not. good. The science is still out on exactly how much
and what someone should drink while they’re running. So it’s best to use common sense: Distance
running, especially when it’s hot out, can make you rather thirsty. So if you want to enjoy the experience, make
sure you take in some fluids when your body says that would feel nice, thanks. So long distance running is really hard, especially
if you haven’t trained properly. But there is a payoff–and I don’t just
mean the space blanket and free food at the finish line. Some people may recognize a feeling of euphoria
after a grueling workout, often called a “runner’s high.” Recent research shows a connection between
the euphoria and the brain’s endocannabinoid system, the same one that responds to the
active ingredient in pot: THC. Scientists have found high levels of a THC
relative called anandamide in runners’ blood after they work out. That leads to an increase of every brain’s
favorite molecule and the one that results in the “high”: dopamine. Some of us at Reactions, really dig this distance
running thing. Others -ahhhh- not so much. Are you a runner? Or are you more of a couch-based athlete? Let us know in the comments, along with your
other sports chemistry questions. Thumbs up and subscribe on the way out, we’ll
see you again soon.

92 thoughts on “The Science of Distance Running

  1. @2:22 the Ketones molecule doesn't have a ketone functional group. It only contains an ester and alcohol. Can someone explain what I'm missing?

  2. what about fat adapted athletes who only use water during marathons? you're only educating on one side of the equation, which is misinformation…

  3. How do you guys feel about ketosis diets in relation to this? Doesn't forcing your body into a state of ketosis mean that you're already starting your race past 'the wall'? I bet that would mean terrible endurance.

  4. I ran my first marathon on Sunday in Franktfurt and i can recommend it to anyone.
    The feeling when you cross the finish line is incredible, its way better than pot and just lets you feel amazing!

    PS.: Avoid stairways the day afterwards ^^

  5. I love these reactions videos! Great reminders of relevant science behind the everyday – just want a science teacher needs to stay up to date. As a hobby athlete, I can really relate to this episode. ( :

  6. Been running for a long time but I never knew you start burning fat at the 20 mile mark. Thanks for this video 🙂

  7. Studies also show that carb loading needs to be preceded by a week of not eating carbs, just like taking caffeine helps if you haven't taken any for a week as well.

  8. I've heard about some newer study saying that not eating any carbs before a run, but rather eating fat for fuel is better since you won't hit "the wall" and thus can keep your energy up during the whole run.

  9. iam a mid distance runner, 5k-10k, mostly because i have to do do strength training and hiit Training just after running. I would love if you post a video on science behind MMA FIGHTS, because it involves almost all muscles and both aerobic and anaerobic respiration.

  10. interesting, so what happens after running a long distance when in the ketonic state? is it possible to top up on fat and protein rather than carbs to keep going or is that something the human body doesn't agree with or isn't designed for?

    Also, how long could you could go without cars just in general life?

  11. Great marathon runners don't eat pasta, they consume anti-inflammatory foods. Most pasta, unless whole grain only causes your blood sugar levels to spike, causing inflammation. It's better to consume greens, vegetables etc.

  12. I actually have drive in my life and I’ve lost 20 lbs, run 5 mi daily, do calisthenics and I’ve ran 3.82 mi in 31:34 and I’m on a quest to getting ripped in 2018 and I will never let myself venture away from fitness.

  13. Can you simply mix some kitchen salt in your drink used while running (I for example simply take water mixed with a bit of fruit sirup to keep med going) or does it have to be the mix of salts in an energy drink?

  14. Good information, I usually just drink a bottle of water, or Gatorade, and eat a pickle and I'm good to go.

  15. New runner, just did 10K for the first time yesterday! 1 hr 4 min. Goal is to work up to a half marathon eventually. Biggest advice I could give, do not go too fast! Find your comfortable pace!! I’m doing a 9-10min per mile pace & that feels good but when I started I was doing 7 min & couldn’t last. It’s OK to go slower! 🏃🏻‍♀️🏃🏻‍♀️🏃🏻‍♀️🏃🏻‍♀️

  16. Awesome video thanks for the share! I recently put out another marathon training tip video that would compliment this video well! Overall the goal is to make sure everyone has the knowledge to train for a full marathon safely! Great work!

    https://m.youtube.com/watch?v=kL-QCBOa_pw&index=2&t=0s&list=LLBZVICtFLl8YthxPgy0eL_A

  17. So I used to run, but I haven't run in over a year and I've gained a bunch of weight since I stopped. Have any of you done this and been able to get back into it? Was it hard or easy? What motivated you to get back into it?

  18. A runner for sure , but lately, more time on the couch 🛋, had a few issues plantar fasciitis , general ankle and knee issues 😬 ! Having said that , I did a 5.3km race on Saturday in around 30minutes

  19. I’m a runner! Used to be a couch potato. Actually mystic messenger got me running thanks to Zen always talking about his workouts. It motivated me!

  20. You underestimated the fat burning. It does not start when glycogen finishes, it starts ong before that. What is more, elite athletes try to train their bodies to start burning fat sooner in the race in order to have that source of energy from as soon as possible (fats are really aloric, they give much more energy than glucose).

  21. I love watching people work out on TV from the comfort of my amazing couch while inhaling bags of chips, buckets of ice cream and of course chugging beer..that's my workout

  22. I'm sorry but elite marathon runners are the ultimate athlete. Holding a 4:40 (sometimes lower) mile for over 26 miles?! I mean most people can't hold that pace for half a mile

  23. Thank you! This explains so many things! I went on my first 25k yesterday and in the last 5 km of the run, I started getting cramps in my legs. I felt like I was dying inside and was quite confused about why I was feeling that way. I drank water, but knew nothing about sodium and carb loading. I can't wait to recover and try again by utilizing the tips you provided in this video. 🙂 Good luck on your marathon! I wish I can do one too eventually. =)

  24. Can you avoid bonking altogether by taking energy gels during the run. Let's say 5 or 6 during a marathon?

  25. I ran 20 miles outside last december just for the hell of it. I did experience a runners high, which is basically just an extreme feeling of relaxation.

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