What Too Much Exercise Does To Your Body And Brain
If working out is good for you, then working out more can only be better for you, right? Not quite. Too many trips to the gym or cardio sessions could actually undo all of those gains you've been working towards. Worse, they might be doing damage to your heart, arteries and causing your brain to become addicted to exercise. Scary stuff! Tech Insider tells you all you need to know about tech: gadgets, how-to's, gaming, science, digital culture, and more. Subscribe to our channel and visit us at: http://www.businessinsider.com/sai TI on Facebook: https://www.facebook.com/techinsider TI on Instagram: https://www.instagram.com/tech_insider/ TI on Twitter: https://twitter.com/techinsider -------------------------------------------------- Following is the transcript of the video: Exercising is supposed to be good for you. It can help you stay at a healthy weight, improve your cardiovascular health, and even ward off depression. But like most things, it’s possible to over-do it. And getting too much exercise can have serious consequences for your body and brain. So, what exactly is “too much” exercising? Well, it depends on factors like your age, health, and choice of workouts. But in general, adults should get around 5 hours a week of moderate exercise or 2-and-a-half hours of more intense activity. Or some combination of the two. That's according to the CDC. But research shows that going way above and beyond that doesn’t increase your health benefits. One unsurprising study found that light to moderate runners had a lower risk of death than people who didn’t exercise. But, in a surprising turn, some people who ran at a faster pace for more than 3 times a week had a similar risk of dying as the non-runners. So running too much, and too intensely, seems to undo some of the health benefits gained from regular running. Extreme endurance exercises, like ultra marathons, may also lead to heart damage, heart rhythm disorders, and enlarged arteries, in some people. Experts believe extreme endurance puts extreme demands on the cardiovascular system. One study found that repeated extreme exercises can “remodel” the heart, thickening the muscle’s walls and scarring tissue. Another study showed that women were less likely to have a heart attack or stroke, if they were physically active at least once a week. But that risk of heart attacks and strokes shot up for women who exercised strenuously every day. So, excessive exercise doesn't provide more benefits than moderate exercise. And it could be more risky. Women are at particular risk for what's known as the "female athlete triad" that includes: loss of menstruation, osteoporosis or bone mineral loss and eating disorders. These symptoms usually arise from a combination of overexercise and calorie restriction. For men, intense exercise has been shown to decrease libido. Possibly due to physical fatigue and lower testosterone levels. For both men and women, overexercise raises the risk of overuse injuries, like tendinitis and stress fractures. These injuries result from repetitive trauma. Your immune system can likewise suffer. While moderate exercise can improve your immune system, excessive exercise can actually suppress it. There's up to a 72-hour "open window" of impaired immunity after intense exercise. This basically means viruses and bacteria might have an easier time invading and infecting the body. And athletes who overexercised also experienced more upper respiratory tract infections. So, we know excessive exercise can wreak havoc on your body — particularly your heart, tendons, ligaments, and immune system. And for around 1 million people in the US, exercise addiction is wreaking havoc on their brains. Symptoms of exercise addiction include withdrawal — that's when you feel anxious or exhausted when you miss a workout. Or feeling a lack of control and unable to cut down on exercise. Even when you know it's hurting you. Now, it’s important to understand that you shouldn't just give up on exercising. The key is to get the right amount. So, feel free to go forth and run. Just not all the time.
What Really Happens During A Brain Freeze
Drinking cold beverages is a great way to fight off the summer heat, but if you drink too quickly, it could lead to a brain freeze. But is your brain actually getting cold? Science Insider tells you all you need to know about science: space, medicine, biotech, physiology, and more. Subscribe to our channel and visit us at: http://www.businessinsider.com/science Science Insider on Facebook: https://www.facebook.com/BusinessInsiderScience/ Science Insider on Instagram: https://www.instagram.com/science_insider/ Business Insider on Twitter: https://twitter.com/businessinsider Tech Insider on Twitter: https://twitter.com/techinsider -------------------------------------------------- Following is a transcript of the video: Ugh, brain freeze! It’s awful. That sharp searing pain in your forehead! But you know what’s even worse? Not everyone gets it! That’s right, some people can suck down as many milkshakes as they want and never feel a thing. Life is so unfair. And you know what else? These lucky people are ruining it for scientists, too. Brain freeze is one of those scientific mysteries that’s been around since the 1800s. Just throw it in there with UFOs and crop circles. We may never know the real reason behind them! Ok, maybe that’s a bit of an exaggeration. But here’s the thing: The leading theories for what causes a brain freeze have to do with a physical response that everyone should feel. The way scientists think it works is this: Brain freeze happens when something cold hits the roof of your mouth, where it triggers your trigeminal nerve. It’s the nerve in charge of sensations you feel around the front of your head. That’s why, when you freeze it to subzero temperatures, the pain is around the temples and forehead. In fact, different nerves cause pain in different parts of your head. A toothache, for example, can irritate the mandibular nerve, causing pain near the central skull. But when it comes to a brain freeze the source of the pain is different from most other headaches. Turns out, it’s more similar to why your feet and hands sting when they get too cold. Your body floods that area with blood to try and return it to body temperature and in the process, your blood vessels expand, which causes that throbbing pain. Similarly, during a brain freeze, blood vessels in your brain widen, sending a rush of blood to the roof of your mouth and, in the process, cause pain. Now, the trigeminal nerve is a natural part of the body. So, if it’s the real cause of brain freeze, then that means everyone should get it. So why do scientists estimate that only 37% Americans actually feel it? And for that matter, 41% of children in Taiwan and only 15% of the adults in Denmark, according to another study? Researchers can only speculate: Maybe the trigeminal nerve is less sensitive in certain demographics. One thing that does seem to be clear is that people who do experience brain freeze may also be more susceptible to another kind of mysterious headache: migraines. In one small study, 93% of migraine patients were also prone to brain freeze. Which has led researchers to suspect that the trigeminal nerve also plays a key role in migraines. Whatever the reason, just hang in there. Brain freeze usually only last 20-30 seconds. Go ahead and take that time to remember not to slurp so quickly next time.
3 Surprising Ways Humans Are Still Evolving
Evolution gave humanity powerful brains, flat feet, and opposable thumbs. But it's not through with us yet. Humans are still evolving new traits that help us survive and thrive in a changing world. ------------------------------------------------------ Science Insider tells you all you need to know about science: space, medicine, biotech, physiology, and more. Subscribe to our channel and visit us at: http://www.businessinsider.com/science Science Insider on Facebook: https://www.facebook.com/BusinessInsiderScience/ Science Insider on Instagram: https://www.instagram.com/science_insider/ Business Insider on Twitter: https://twitter.com/businessinsider Tech Insider on Twitter: https://twitter.com/techinsider ------------------------------------------------------ Following is a transcript of the video: On the outside, it may seem like we haven’t changed much from our early ancestors. But take a closer look and you’ll discover that humans are still evolving in some fascinating new ways. HOLDING YOUR BREATH The average person can hold their breath for 30 seconds. But Bajau people in Southeast Asia can hold it up to 12 minutes! Which comes in handy when they freedive over 230 feet for food. Part of the reason is simply training and experience, since they spend over half their work day underwater But it turns out the Bajau also have a genetic mutation that makes their spleens 50% larger than average. Our spleens are what filter and store oxygen-rich red blood cells. So, when the Bajau dive underwater their larger spleens contract, which boosts oxygen levels in the blood by up to 10%, allowing them more time to collect food. It’s a handy adaptation that probably came from living on houseboats for the last 1,000 years. DRINKING MILK About 35% of the world’s population has the equivalent of a genetic superpower: They can digest milk as adults. Not impressed? Then consider this: humans are the ONLY mammals on the planet with this ability. Thanks to a genetic mutation that popped up in Europe around 5 to 10 thousand years ago. Those with the mutation produce lactase throughout their lives. That’s the enzyme that breaks down milk sugars for easy digestion. All other mammals, and humans for most of history, stop producing it after childhood. But once those lucky few Europeans could drink milk as adults, that suddenly meant extra nutrition and ultimately healthier, longer lives so that they could pass their superpower on to future generations. Today, roughly 95% of Northern Europeans have the mutation. FENDING OFF DISEASE The human body has an estimated 20 to 30 thousand genes. And while some mutations can change our spleens and diet others can protect us against deadly conditions, like AIDS. Nearly 50% of women in parts of South Africa have HIV. But researchers found that some show a stronger resistance to the virus taking longer to develop AIDS, or sometimes never getting it at all. Turns out, these women also share a mutation in a gene called HLA-B27, that the others lack. Does this mean we're going to evolve our way to HIV immunity? It’s too early to say. But one thing’s clear: Evolution’s not done with us yet.