Here's why the heart doesn't need to rest like other muscles - We Are The Mighty
MIGHTY FIT

Here’s why the heart doesn’t need to rest like other muscles

Mindy N. asks: After a long run my leg muscles are tired, but my heart is not. Why doesn’t the heart need any rest?

An average of around 60 to 100 times every minute of every day of every year of your ultimately meaningless life, your heart beats… until it doesn’t. Not long after it stops, all knowledge of your having existed is rapidly forgotten. Unlike the other muscles in your body, however, your heart steadfastly rages against the dying of the light, refusing to ever get tired. But how does it manage this and why are your other muscles such slackers in comparison?

To begin with, the human body is broadly composed of three types of muscles: skeletal, smooth and cardiac. Skeletal muscles are striated (banded), and are what most of us think of when we envision a muscle — controlling pretty much all voluntary, and some involuntary, body movement.


Like cardiac muscle, skeletal muscle derives energy from ATP (Adenosine triphoweknowyoudontcare), with this being made in a few different ways. To avoid going full textbook, we’ll just briefly give the high level over simplified view here. In a nutshell, the slowest, but most efficient, method of ATP production is via aerobic respiration where mitochondria in your muscle cells draw energy from the Dark Dimension, producing ATP, a small amount of which is stored in your muscles at any given time. This stored amount is a sufficient supply to last for about 3 seconds of vigorous activity, not unlike your high school boyfriend.

Here’s why the heart doesn’t need to rest like other muscles

Diagram of the human heart.

After this supply is taxed, with the ATP converted to ADP (adenosine diphosophate) in the process, creatine phosphate in the muscles is used to convert it back to ATP. This supply will last about 8-15 seconds.

Next up, it turns out we were totally wrong about that whole Dark Dimension thing as, in fact, your muscles continue to get ATP beyond this via a series of chemical reactions resulting in glucose being used to make the needed ATP to keep going. This glucose comes from a variety of sources, such as glycogen in your muscles, or via blood via fats, protein, stores in the liver, and from your food churning away in your intestines.

There are two high level ways this production of ATP ends up being accomplished. In the first, using large supplies of oxygen. In this case, as much as 38 ATP molecules can be produced for every glucose molecule. In the second case, via anaerobic glycolysis — not requiring oxygen — only 2 molecules of ATP are produced for each molecule of glucose. While an extremely inefficient use of the available supply of glucose, this method at least produces the ATP over two times faster than aerobic respiration and continues working for a time while you’re out of breath.

Due to glycolysis resulting in the accumulation of lactic acid in the muscles, ultimately if it accumulates faster than it can be gotten rid of, it will interfere with the anaerobic glycolysis process and your muscles are going to go all jelly and cease to work as well for a little bit. This is in part why, if you get out of breath when exercising and your body is relying more on anaerobic glycolysis, you get fatigued extremely quickly. In this case, you’re simultaneously creating lactic acid at a much more rapid rate and using up your available glucose molecules faster, but producing relatively small amounts of ATP for those molecules used. Do this for more than a minute or two and it will overtax your skeletal muscles’ ability to produce the needed ATP at the rate you’re using it. (Though, again, your mileage will vary based on your current fitness level.)

Here’s why the heart doesn’t need to rest like other muscles

(Photo by Annie Spratt)

Back it off and so you’re relying mostly on aerobic respiration and you’re going to get the most bang for your buck, able to keep going all night long if you keep hydrated and well fed. Slow and steady wins the race.

Unsurprisingly from all of this, the more mitochondria there are, the faster ATP can potentially be produced if the needed molecules are present and the more the muscle can keep on keeping on. As for skeletal muscle, about 2%-8% of the volume of such muscle is mitochondria, though this varies somewhat from person to person depending on your level of physical fitness.

Moving on to smooth muscle, as you may have gleaned from the name, this is smooth with no striations. Found in your hollow internal organs (except the heart), smooth muscles work automatically, helping you digest food, dilate your pupils and take a wee-wee. As an example of smooth muscle in action, in digestion, the contractions themselves are really not too dissimilar to how your heart beat works — fluctuation of electrical potential in the smooth muscle cells which causes the muscle to contract in a rhythmic fashion, in this case called the “Basic Electrical Rhythm” or BER. This rhythm is about three times per minute in the stomach, and 12 times per minute in the small intestines. The sound you are hearing when your stomach and intestines make noise is the result of these muscular contractions mixing and moving chyme (the cocktail of digestive juices, food, microbes, etc.) and air along down the tube between your mouth and your waste disposal port.

As for the mitochondrial needs of these muscles, they are typically approximately that of your skeletal muscles, with mitochondria making up about 3-5% of the smooth muscle volume.

This finally brings us to the real hero of your life story — cardiac muscle. Like skeletal muscle, cardiac muscle is striated and like the other muscle in your body is primarily powered by mitochondria. The cardiac muscles, however, have as much as 10 times the density of mitochondria as your other muscles, at about 35% of the volume of your cardiac muscle.

It should also be noted that individual muscle cells in the heart actually do get regular rest thanks to how the heart beat actually works, which we’ll get into in the Bonus Fact in a bit. But the net result is that about 60%-70% of your life a given part of your heart is actually in a resting state.

Here’s why the heart doesn’t need to rest like other muscles
Giphy

Combining these micro-rests with the extreme amount of mitochondria and a large amount of oxygen from the heart’s awesome blood supply, this allows your heart all the ATP it needs to not get tired, assuming you’re not in an extreme state of starvation or doing some extreme form of exercise for extended periods well beyond your normal fitness regime.

On that note, the downside to needing so much ATP thanks to no extended downtime is that the heart really needs to rely on aerobic respiration to make sure it doesn’t run out of ATP, and thus it doesn’t take oxygen being cut off for too long from it before you’re going to have a bad time, unlike other muscles you can just stop using to help recover the needed ATP over time.

And, yes, it turns out the human heart can actually get tired and suffer damage if you’re trying to do some extreme form of physical activity outside your norm for lengthy periods, especially if in a low oxygen environment like at high altitude. In these cases, even the healthiest hearts can suffer damage, though given the other effects on your body of such extreme physical activity, typically most people will stop doing whatever before the heart is negatively impacted in a damaging way. In essence, your legs will give out before your heart does (usually), at least when talking energy supply. But that doesn’t mean in certain cases a measurable level of tiredness in the heart can’t be observed.

For example, in 2001, cardiologists studied a few dozen endurance athletes competing in a 400 km race in Scotland, which comprised of all manner of physical activities from paddling, rope climbing, running, biking, climbing, etc. and the whole event taking almost 100 hours. During this span, the athletes typically only slept about 1 hour per 24 hours during the event and otherwise soldiered on.

The results? At the end of the race, the athletes’ hearts were only pumping about 90% of the volume per beat they’d been managing before the race started.

Showing the resilience of the heart and its mitochondrial baddasery, Cardiologist Euan Ashely, who was involved in the study, stated that “the athletes’ hearts that showed signs of cardiac fatigue did return to normal fairly quickly after the race and no permanent damage was done.”

Here’s why the heart doesn’t need to rest like other muscles

(Photo by Boris Stefanik)

That said, further research on endurance athletes calls into question the notion of “no permanent damage” being done. For example, researchers involved in a 2011 British study looking at British Olympians who competed in distance running and rowing (and specifically competing in at minimum a hundred events), found that as they aged they showed marked signs of heart muscle scarring, something that can lead to irregular heart function and, potentially, heart failure.

Of course, these are extreme examples, and for most people not doing ultra marathons regularly or competing professionally or semi-professionally in endurance events, this is unlikely to be a problem and the holistic health benefits of regular, vigorous exercise are likely to make up for it even then.

Bonus Fact:

Ever wonder how the heart beat works? Well, wonder no more. In a nutshell, the heart is a four chambered pump. The top two chambers are called Atria, the bottom two are called Ventricles. They are separated from top to bottom by valves; the right and left sides are separated by a septum. So what makes the pump squeeze? When the hearts muscle gets “shocked”, it will contract and force the blood down its path, with the valves not allowing blood to flow back through the system, unless they are defective.

The blood’s path through the heart starts in a vein called the Superior Vena Cava. Then it enters the right atrium, flows through the tricuspid valve into the right ventricle. From there it travels through the pulmonic valve into pulmonary arteries, then the lungs. Now back to the heart and into the left atrium, through the mitral valve. The blood is now in the “strongest” chamber of the heart, the left ventricle. From there it gets pumped through the aortic valve and into the aorta and out to the rest of the body!

So what causes that infamous electric shock the heart receives approximately 60-100 times a minute? Short answer: Dormammu. Long answer: The exchange of electrolytes across specialized cells within the heart build up a differing electrical potential on either side of the cell. When this electrical potential reaches a certain level, it discharges and sends a shock down another unique set of cells within the heart, causing a shock and thus the contraction.

Here’s why the heart doesn’t need to rest like other muscles

The specific set of cells that regulates the heart rate (in most people) are called the Sinoatrial node or SA node for short. The SA node (pacemaker of the heart) sits in the upper portion of the R atria near the entrance of the superior vena cava.

When the SA node sends out and electrical shock, it immediately shocks the atria. The pulse then gets “held up” in another set of cells called the Atrioventricular node, or AV node for short. This then transmits the impulse down to the bundle of His and then to two pathways called the right and left bundle branches. Then it’s transmitted to the rest of the Ventricles through what are called Purkinje fibers. All together this “shock” causes the atria to contract, then the ventricles. You’re still alive! (For now.)

So what and how do these electrolytes cause this shock? In an attempt not to give a physiology lecture of ungodly proportion, we will simply say that the main two electrolytes involved are sodium and potassium. Potassium normally sits inside the cell, and sodium outside. Potassium slowly leaks outside of the cell and sodium then goes inside the cell. This creates the differing electrical potential that builds up until the point of discharge. Other electrolytes also help in creating this differential, and they are calcium and magnesium. All together the harmony created by this yin and yang system of electrical and mechanical systems come together to make that wonderfully thumping thing inside your chest!

This article originally appeared on Today I Found Out. Follow @TodayIFoundOut on Twitter.

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This is what basic Marine infantry training is like

If you know anything about Marine infantry, you know that we’ve built up one h*** of a reputation over the past 243 years. Whether it’s destroying our enemies or our profound capability to drink an entire town dry of alcohol, one thing is for sure — we’ve made a name for ourselves. But, the biggest and most important reputation is the one we have on the battlefield.

But the infantry plays the biggest role — closing with and destroying the enemy. Some may even regard us as the best in this respect but, to be the best, you have to train like the best from the ground up. This all starts at the Marine Corps School of Infantry so here are some things you should know about how the Marine Corps makes Infantry Marines:


Here’s why the heart doesn’t need to rest like other muscles

You’ll be pushed further than you were in boot camp.

(U.S. Marine Corps photo by Cpl. Chelsea Anderson)

Infantry training is tough

You probably expected as much. But, let’s get this out of the way now: it’s tough but it’s not as tough as you’ll think it is. There are going to be lots of challenges but remember that the goal is to mentally and physically prepare you for being a professional war fighter.

Here’s why the heart doesn’t need to rest like other muscles

A lot of late nights and early mornings, but it’s for the best.

(U.S. Marine Corps photo)

Sleep deprivation

Not unlike the first 48 hours of boot camp, you’re deprived of sleep. Very unlike the rest of boot camp, the sleep deprivation doesn’t end after the first 48 hours. In fact, you might develop a mentality like, “I can sleep when I get to my unit.” But, chances are, you won’t.

Here’s why the heart doesn’t need to rest like other muscles

It’s better than nothing though.

(U.S. Marine Corps photo by Lance Cpl. Shane T. Manson)

Malnourishment is a common side effect of joining the infantry

In boot camp, you get three meals at the mess hall each day with the exception of field week, where you get MREs, and the Crucible, where you get, like, one MRE for three days. In SOI, you get nothing but MREs – and believe me, your gut will feel it.

There might even be times your instructors don’t pull your platoon aside to make sure you eat; you’ll just have to eat when you can.

Here’s why the heart doesn’t need to rest like other muscles

Okay, you might get tents in your unit.

(U.S. Marine Corps photo by Cpl. Donato Maffin)

Sleeping indoors is rare

You might have expected this. Infantry Marines sleep outside no matter what. Sleeping inside is something you only get to do when you’re out of the field so get used to sleeping in the dirt under the rain.

Here’s why the heart doesn’t need to rest like other muscles

Remember that they’re teaching you a lot of valuable lessons, even by being tough.

(U.S. Marine Corps photo by Cpl. Orrin G. Farmer)

The instructors are more harsh

Just because they don’t scream in your face all the time like Drill Instructors doesn’t mean they’re better. Combat Instructors are, in a way, much easier to deal with. Overall, they’re way more harsh in the long run because they know you might end up in their squad or platoon and they want to make sure they trained you well enough to be there.

MIGHTY TRENDING

5 of the ways to lose the “once a Marine, always a Marine” status

You see and hear this term all the time: “former Marine.” And, wherever you see it, you’ll also see Marines telling you (and everyone else) why we hate it. Sure, there are a few folks out there who agree with it, but those of us who hold the title near and dear to our hearts will tell you a different story.

In my opinion, there’s a damned good reason for the expression, “once a Marine, always a Marine.” Others disagree.


To be fair, this is not a mentality exclusive to Marines. Just because you “get out” doesn’t mean you’re no longer a Marine, soldier, airman, coast guardsman, etc. You don’t just instantly forget everything you’ve learned and experienced over the past few years once you get your DD-214. Joining the military makes you a part of a fraternity and you’ll find that you resonate better with other veterans than you do with people from any other walk of life for one simple reason: You became a part of something much larger than yourself.

Your membership was paid for in blood, sweat, and tears, along with the countless hours you spent dedicated to the cause. To say a veteran is an “ex-” anything is highly inaccurate.

However, there are certain qualities (mostly conscious choices) that define a former Marine. These are just a few of those qualities:

Here’s why the heart doesn’t need to rest like other muscles

Maybe you just need some new Drill Instructors…

(U.S. Marine Corps)

Severe lack of discipline

It’s easy to fall into the trap of letting your discipline slide when you get out — in fact, a lot of us are guilty of this. But at some point, we pick it back up and we reintegrate it into our lives. To allow this discipline to drop off entirely is most definitely a conscious choice — one that can lead to the discontinuation of other hard-earned qualities.

Forgotten core values

No matter which branch you join, you’ll first learn the core values and then you’ll embody them. Those values shape your personal code and you live by them while you’re in the military. When you get out, if you aren’t still using them to find some direction in life, you’ve earn the “ex” in front of your title.

Here’s why the heart doesn’t need to rest like other muscles

Just remember what you learned.

(U.S. Marine Corps)

Lack of leadership

Almost everyone comes out of the military with some type of leadership capabilities. Something you hear often in the military is, “in the absence of leadership, be a leader.” This applies heavily to civilian life because there’s often severe absence of leadership. If you get out of the military without learning how to take control from time to time, you likely didn’t learn much else.

Lack of punctuality

We’re all guilty of being late to something at some point. It just happens, it’s the way of life. But, those who learned anything from time in service will remember the factors that played into that tardiness, both self-inflicted and external, and ensure it doesn’t happen again.

If you’re choosing to be late because you just don’t care — you’ve given up your title.

Here’s why the heart doesn’t need to rest like other muscles

If you define yourself as an “ex-Marine,” by all means.

(U.S. Marine Corps)

A conscious decision to no longer be a Marine

There’s a common belief among those who served that states you should always work to justify the fact that you’ve earned the right to be called a Marine (or solider, or airmen, etc). You should continuously employ the values learned in service in forming your civilian life.

There is, however, another side to this — and it’s simple. If you decide you’re no longer fitting of that title because you’ve grown a beard or whatever other, arbitrary reason, then you aren’t.

Many of us still believe in our titles and we’re willing to continue to honor it. It’s a lifetime effort and, if you’re not willing to make the commitment, nobody else will make it for you.

MIGHTY TRENDING

The US threatens to sanction Turkey over an American pastor

U.S. President Donald Trump says Washington is ready to impose “large sanctions” on Turkey unless authorities there allow a U.S. pastor being detained on house arrest to go free.

“The United States will impose large sanctions on Turkey for their long time detainment of Pastor Andrew Brunson, a great Christian, family man, and wonderful human being,” Trump wrote in a tweet.


“He is suffering greatly. This innocent man of faith should be released immediately!” he added.

Turkish Foreign Minister Mevlut Cavusoglu issued a Twitter statement shortly afterward saying that “no one dictates [to] Turkey.”

“We will never tolerate threats from anybody. Rule of law is for everyone; no exception,” he wrote.

Trump’s comments come an hour after Vice President Mike Pence issued a similar threat, warning of “significant sanctions” against Ankara.

“To President [Recep Tayyip] Erdogan and the Turkish government, I have a message on behalf of the president of the United States of America: Release Pastor Andrew Brunson now or be prepared to face the consequences,” Pence said, speaking at a State Department event in Washington to advance religious freedom.

Brunson, who has worked in Turkey for more than 20 years, was jailed in 2016 and was indicted a year later on terrorism and espionage charges, accused of aiding groups Ankara alleges were behind a failed military coup in 2016.

Brunson was held in custody until July 25, 2018, when he was transferred to house arrest.

Secretary of State Mike Pompeo said the move to house arrest was “not enough” and that he should be allowed to leave Turkey.

Featured image: Turkish Foreign Minister Mevlut Cavusoglu

This article originally appeared on Radio Free Europe/Radio Liberty. Follow @RFERL on Twitter.

MIGHTY CULTURE

This is why the BCGs aren’t really all that bad

The old saying, “women love a man in uniform” comes with a long list of exceptions. For example, the expression does not apply to service members wearing a pair of S9 GI glasses — more commonly known as “birth control glasses,” or BCGs. Even the updated 5A GI glasses are only just a slight improvement in style over their infamous predecessor.

The distaste held by many troops wearing them isn’t without merit. You’re asking big, badass troops to don a pair of prescription glasses that immediately makes them look like the biggest dorks on the face of the planet. But if you can get over the fact that you’re often going to be mistaken for the commo guy, you’ll see there’s a very valid reason why the military has issued them out for all these years.

And it’s related to one of their other nicknames: up-armored glasses.


Here’s why the heart doesn’t need to rest like other muscles

This soldier’s look has been appropriated by hipster douchebags who raise hell if their organic kale smoothie wasn’t free-range.

(Tennessee State Library and Archives)

The very first version of GI glasses were issued out back in WWII. The P3 lenses they used were originally meant to be inserts for gas masks — but your average, visually impaired troop needed to see clearly, so the military started issuing out their own version of prescription glasses.

After the war, they switched the frames from a nickel alloy to cellulose acetate. Recipients could choose between gray and black frames. The glasses weren’t too out of the ordinary style-wise and they served a dual purpose of acting as thicker-than-average eye protection while improving a troop’s sight.

For the time, the glasses were aligned with fashion trends and, frankly, style wasn’t much of a concern — they were free, they worked, and they were definitely within military regulations. It was just a bonus that they didn’t look too bad, either.

Here’s why the heart doesn’t need to rest like other muscles

They can do anything but help you talk to the ladies.

(Photo by Sam Giltner)

Then, the late 70s rolled around and the military went all in on the S9 GI glasses. The frames were bulky and only available in “librarian brown” cellulose acetate. Around this time, soft corrective contact lenses became more prevalent, but military regulation forbid contacts, so if you had a visual impairment, you were forced to look like a dork.

The restriction on contacts isn’t without merit. As anyone who’s ever worn contacts can tell you, they’re a pain in the ass to maintain everyday and almost impossible to keep up with in a military environment. A single speck of dirt can potentially irritate your eye and take you out of the fight. The S9s on the other hand, were intended to withstand the austere environments troops deploy to and the lenses and frame are durable.

Here’s why the heart doesn’t need to rest like other muscles

All of the jokes we throw at each other for looking dorky as hell will soon be a thing of the past. Now we’ll need some other trait to poke fun at…

(Photo by Melissa K. Buckley, Ft. Leonard Wood)

The military has adapted to societal trends over the years to keep troops seeing properly and protecting their eyes. Wearing BCGs is a regulation that’s really only enforced during recruit training or Officer Candidate School. After the bespectacled troop gets to their first unit, they can swap them out for a pair of civilian, prescription glasses — so long as they don’t have any brand logos on the sides.

The modern version of the GI Glasses — the Model 5A — were released in 2012 to replace the awkward S9s. They offer the same protection, are still free, and they come in a variety of style options from which the troop can choose.

MIGHTY CULTURE

To DITY or not to DITY?

With each set of PCS orders, I wonder whether we should consider a Personally Procured Move (PPM), which is the official name of what most of us call a DITY, or Do It Yourself move. It’s tempting — you hear stories of military families making tons of money, and it seems like there is less chance of damaged goods. If you’re considering a DITY move this PCS season, here are six questions you need to ask yourself:

How much reimbursement will you get?

For most people, the main reason to consider doing a DITY move is to make a little money. Before you get started, be sure you understand exactly what you will and will not receive, whether you do a DITY, a full government move, or something in between.

All service members who are executing PCS orders are entitled to a wide range of travel entitlements, including:

  • temporary lodging,
  • monetary allowance in lieu of transportation (technically called MALT, but often just called mileage),
  • per diem for travel days,
  • dislocation allowance.

When you do a DITY move or a partial DITY move, you’ll also get an allowance for moving your belongings, based upon the distance and weight moved. From that allowance, you pay all the expenses of the move: packing materials, hired help, the actual transportation of your goods, and unpacking. Any excess reimbursement beyond your actual expenses is taxable income.

Contact your personal property office to be sure you understand your entitlements and the reimbursement requirements for your branch, including when you need to have your vehicle weighed (empty/full/both? start/finish/both?).

Can you manage an upfront cost?

All branches have a process for getting an advance of a portion of your anticipated move reimbursement, but it doesn’t always work out as expected. If you decide to do a DITY move, you should plan to pay for all expenses out-of-pocket and expect that it may take months to be reimbursed.

Here’s why the heart doesn’t need to rest like other muscles

Is moving yourself realistic?

Doing a DITY move is work, especially if you have a lot of stuff or heavy things like a piano or old-school entertainment center. Do you realistically have the time, mental energy and physical strength to pack up everything you own, load it safely onto a truck — or into a moving container — and unload it all on the other end?

Do you have a lot of professional gear?

One major limitation of a full DITY move is there is no way to separate out professional gear weight. Service members and their spouses are permitted to deduct the weight of certain specified work-related items from the overall weight of goods. Separating professional gear is a big help if you are close to your weight allowance.

Will you be able to keep track of the paperwork?

DITY moves require extra paperwork and receipts, particularly when you go to file your income tax return. You’ll need weight receipts to get reimbursed by the military — requirements may vary by branch. Then, because DITY reimbursements are taxable income, you’ll need all your expense receipts to deduct from your income.

TIP: Experienced DITY movers recommend a designated folder or envelope for receipts, but also taking a photograph of every single receipt when you get it. Upload the picture to the cloud to ensure you’ll always have access to a copy.

Have you considered a partial DITY?

One of the easiest ways to get the benefits of a DITY move without the work is to do a partial DITY, which separates your move into two parts. The government movers take care of the things you don’t want to move, and you get reimbursed for the portion you do move. A partial DITY is a good solution if you aren’t sure you want to do a full DITY, or if you have certain items you want to move yourself.

DITY moves are a good option for different situations, but they are a lot of work and they may or may not make money. Understanding the reimbursements and the process will help you decide if it is the right option for you.

This article originally appeared on Military Families Magazine. Follow @MilFamiliesMag on Twitter.

MIGHTY TACTICAL

How a 200-year-old engine is changing sub warfare

Swedish submarines have proven themselves in exercises against the U.S. One of their subs successfully lodged a kill against the USS Ronald Reagan as the carrier’s protectors stood idly by, incapable of detecting the silent and stealthy Swedish boat. Oddly, the Swedish forces succeeded while using an engine based on a 200-year-old design.


Here’s why the heart doesn’t need to rest like other muscles

The USS Ronald Reagan was sailing with its task force for protection when a single Gotland-class submarine snuck up, simulated killing it, and sailed away without damage.

(U.S. Navy photo by Mass Communication Specialist 1st Class Peter Burghart)

First, a quick background on what engines were available to Sweden when it was looking to upgrade its submarine fleet in the 1980s. They weren’t on great terms with the U.S. and they were on worse terms with the Soviets, so getting one of those sweet nuclear submarines that France and England had was unlikely.

Nor was it necessarily the right option for Sweden. Their submarines largely work to protect their home shores. Nuclear boats can operate for weeks or months underwater, but they’re noisier than diesel subs running on battery power. Sweden needed to prioritize stealth over range.

But diesel subs, while they can run more quietly under the surface, have a severe range problem. Patrols entirely underwater are measured in days, and surfacing in the modern world was getting riskier by the day as satellites kept popping up in space, potentially allowing the U.S. and Soviet Union to spot diesel subs when they came up for air.

So, the Swedish government took a look at an engine originally patented in 1816 as the “Stirling Hot Air Engine.” Stirling engines, as simply as we can put it, rely on the changes in pressure of a fluid as it is heated and cooled to drive engine movement.

That probably sounded like gobbledygook, but the important aspects of a Stirling engine for submarine development are simple enough.

  • They can work with any fuel or heat source.
  • They generate very little vibration or noise.
  • They’re very efficient, achieving efficiency rates as high as 50 percent while gas and diesel engines are typically 30-45 percent efficient.
Here’s why the heart doesn’t need to rest like other muscles

An officer from the HMS Gotland watches the crew of a U.S. patrol plane track his sub during war games near Sweden in 2017.

(U.S. Navy photo by Lt. Brian O’Bannon)

Sweden tested a Stirling engine design in a French research vessel in the 1980s and, when it worked well, they modified an older submarine to work with the new engine design. Successes there led to the construction of three brand-new submarines, all with the Stirling engine.

And it’s easy to see why the Swedes chose it once the technology was proven. Their Stirling engines are capable of air-independent propulsion, meaning the engines can run and charge the batteries while the sub is completely submerged. So, the boats have a underwater mission endurance measured in weeks instead of days.

But they’re still stealthy, much more quiet than nuclear subs, which must constantly pump coolant over their reactors to prevent meltdowns.

Here’s why the heart doesn’t need to rest like other muscles

The HMS Gotland sails with other NATO ships during exercise Dynamic Mongoose off the coast of Norway in 2015.

(U.S. Navy photo by Mass Communication Specialist 2nd Class Amanda S. Kitchner)

So much more stealthy, in fact, that when a single Swedish Gotland-class submarine was tasked during war games to attack the USS Ronald Reagan, it was able to slip undetected past the passive sonars of the carriers, simulate firing its torpedoes, and then slip away.

The sub did so well that the U.S. leased it for a year so they could develop tactics and techniques to defeat it. After all, while Sweden may have the only subs with the Stirling engine, that won’t last forever. And the thing that makes them so stealthy isn’t restricted to the Stirling design; any air-independent propulsion system could get the same stealthy results.

Shortened to AIP, these are any power systems for a submarine that doesn’t require outside oxygen while generating power, and navies are testing everything from diesel to fuel cells to make their own stealthy subs. China claims to have AIP subs in the water, and there is speculation that a future Russian upgrade to the Lada-class will introduce the technology (as of August 2017, the Lada-class did not feature AIP).

So, for the U.S., getting a chance to test their mettle against them could save lives in a future war. And, if it saves a carrier, that alone would save thousands of lives and preserve tons of firepower.

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For its part, Sweden is ordering two new submarines in their Type A26 program that will also feature Stirling engines, hopefully providing the stealth necessary to catch Russian subs next time their waters are violated. Surprisingly, these advanced subs are also cheap. The bill to develop and build two A26s and provide the midlife upgrades for two Gotland-Class submarines is less than id=”listicle-2589628522″ billion USD.

Compare that to America’s Virginia-Class attack submarines, which cost .7 billion each.

MIGHTY TRENDING

U.S. fighters scramble to escort Russian bombers near Alaska

Two U.S. Air Force jet fighters scrambled to escort a pair of Russia Tu-95 strategic bombers that were conducting a flight over the Arctic Ocean, the Bering Sea, and the Sea of Okhotsk on Sept. 6, 2018.

The Russian Defense Ministry on Sept. 7, 2018, confirmed the incident, saying the bombers were performing “scheduled flights over neutral waters” when they were escorted by the U.S. F-22 warplanes.


Earlier, a spokesman for the U.S. Northern Command and North American Aerospace Defense (NORAD), Michael Kucharek, told journalists that the Russian bombers were flying “in the Alaskan Air Defense Identification Zone, south of the Aleutian Islands.”

Here’s why the heart doesn’t need to rest like other muscles

Two F-22s during flight testing.

(U. S. Air Force Photo)

“At no time did the Russian bombers enter Canadian or United States sovereign airspace,” he said.

Featured image: A Russian Tu-95 strategic bomber.

This article originally appeared on Radio Free Europe/Radio Liberty. Follow @RFERL on Twitter.

MIGHTY TACTICAL

This Brazilian trainer thinks it can replace the Warthog

Brazil has had a decent aerospace industry centered on Embraer, a conglomerate that made everything from airborne radar planes to trainers. However, that industry has gotten a little too full of itself lately. They think one of their trainers can replace the A-10.

Now to be fair, this trainer, the Super Tucano, is doing some attack work with the Afghan Air Force and is a contender in the Air Force’s OA-X program, advancing to a fly-off with the AT-6. Two other contenders, the AT-802 and the Textron Scorpion, didn’t make it to the fly-off. Stinks to be them, but honestly, could any of them really replace the A-10?


But we digress. We’re not here to cyberbully a wannabe A-10 to the point that Selena Gomez has to consider making an aviation version of 13 Reasons Why, despite how much fun it would be to really make said wannabe feel really bad about itself. Even though it should… but again, we digress.

Here’s why the heart doesn’t need to rest like other muscles

The fact is, the P-51 Mustang could arguably fly circles around the A-29, but the A-29 makes for a decent trainer.

(USAF photo)

No, we are here to take a look at this plane, which is already giving honorable service in the fight against terrorism. It’s been dropping bombs on al-Qaeda and the Taliban for a bit. It’s in service with over 14 countries.

The Super Tucano boasts a top speed of 229 miles per hour (the P-51 Mustang could hit 437). It can carry rockets, bombs, AGM-114 Hellfire missiles, air-to-air missiles, and gun pods for use against enemy forces. The plane also boasts a maximum range of 2,995 miles. Currently, 205 Super Tucanos are in service around the world.

Here’s why the heart doesn’t need to rest like other muscles

The United States Air Force is one of 14 countries using the Super Tucano.

(USAF photo)

While the winner of the OA-X competition has yet to be determined, the Super Tucano does have a decent track record as a trainer and light attack plane. Learn more about this Brazilian A-10 wannabe in the video below.

https://www.youtube.com/watch?v=FrHqQ1u1yOI

www.youtube.com


MIGHTY TACTICAL

These pistols are carried by NCOs at the Tomb of the Unknowns

Many military members are familiar with the sight of a shift change at Arlington National Cemetery’s Tomb of the Unknown Soldier. Only the U.S. Army’s finest can join the Old Guard and walk the carpet as a tomb sentinel, so the highlight of any visit to Arlington is catching the Changing of the Guard, where the guard’s M-14 rifle is famously inspected during the ceremony.

What you might not notice is the duty NCO’s sidearm, holstered but clearly ready for use. This weapon is as clean as the rifle the NCO inspects, with one important difference for the guards.


Here’s why the heart doesn’t need to rest like other muscles

Firepower.

The M-14 rifles used by the Tomb Sentinels are fully functional, the Old Guard says. While the unit would not discuss further security measures due to the sensitive nature of what they do, it’s clear the rifle isn’t loaded when it’s carried by the men walking the line in front of the Tomb. An M-14 with a magazine is distinctly different than one without. Furthermore, when the rifle is inspected during the Changing of the Guard, the inspection would eject a round from the rifle, were there a round in the chamber.

No one really knows if there are live rounds in the nearby tent or another means for the sentinels to defend themselves in case of an active shooter. But the NCOs are packing.

Here’s why the heart doesn’t need to rest like other muscles

Serious firepower.

When an NCO of the Old Guard attends to the Changing of the Guard, the NCO is equipped with a custom, U.S. Army-issued weapon, the Sig-Sauer M17. The weapon was built by the gunmaker specifically for the Tomb Sentinels and comes with a number of beautiful features. There are only four like them ever created, and all are carried exclusively by NCOs in the Old Guard.

The hardwood in the grip of these special pistols comes from the deck of the USS Olympia, a cruiser first laid in 1895 and seeing service in the Spanish-American War and World War I. Marble from the Tomb of the Unknown Soldier is superheated, converted into glass, and added to the weapon’s sights, making for one of the most unique weapons created for the military anywhere.

Here’s why the heart doesn’t need to rest like other muscles

Since things are so tight at the Pentagon in terms of operational security, it’s not known whether the NCOs are carrying ammunition for the sidearms, but since there is a magazine in the weapon, they certainly could be. After the 2014 shootings at Canada’s Tomb of the Unknown Soldier and subsequent spree on Ottawa’s Parliament Hill, they certainly should be.

popular

5 terrifying things that will happen in North Korea if war broke out

North Korea has finally opened up talks with the outside world. They remained amicable throughout the Pyongyang Winter Olympics and Kim Jong-un recently visited Beijing personally — the first political visit of its kind for the young dictator. Meanwhile, President Trump is preparing for his own visit to North Korea in May. Now, more than ever, it’s important to remember what’s on the line.


If, god forbid, war were to break out between North Korea and the U.S., it would be on their territory. It’s unlikely that they’d risk launching an intercontinental ballistic missile towards American soil, and it’s even more unlikely that a launched missile could go the distance (or make it past the massive number of anti-missile sites between). And although North Korea may boast an impressive number of troops, they lack any real transport capability.

Even with those shortfalls in mind, a wartime North Korea wouldn’t be an entirely benign entity.

Here’s why the heart doesn’t need to rest like other muscles

Take it in… This image could get your grandkids killed if you were a North Korean.

(Warner Bros.)

They will execute all of their political prisoners.

The world knows what North Korea is doing within their political prisons and North Korea knows what they’re doing is wrong. That’s why every guard in North Korea is ordered to execute every single one of the hundreds of thousands of political prisoners — to hide any evidence of their wrongdoing.

Unfortunately, North Koreans are sent to a political prison for an insane amount of petty infractions, like not hanging a picture of Kim Jong-il in the living room or coming in contact with western pop culture. Prisoners are also jailed according to the “three generations” rule, which states that punishments can be levied against the children and grandchildren of an offender.

If Americans showed up, some people might face execution because their grandfather got caught watching The Wizard of Oz fifty years ago.

Here’s why the heart doesn’t need to rest like other muscles

Hell, North Koreans think this guy exercises.

(KCNA)

Their propaganda would go overboard.

North Korean propaganda is hilarious to Westerners because of the ridiculous claims they make. But to North Koreans, it’s no joke. Over generations, people have been made to believe the ludicrous, like the fact that their “supreme leader” doesn’t need to poop.

One of their oldest claims is that the “American Imperialist Wolves,” as we’re known, are going to come and invade. By touching down on North Korean soil, American troops would prove government propaganda correct, giving the regime the credibility to pump out even more outrageous falsities.
Here’s why the heart doesn’t need to rest like other muscles

Fighting a conventional war is terrifying enough. Fighting one alongside a cult-like insurgency would be unheard of.

(KCNA)

Kim loyalists would start a guerrilla war unlike any the world has seen.

The North Korean people have been told for over sixty five years that members of the Kim dynasty are near to gods. Anyone who disagrees has already been executed. Those who remain are the military and the devout.

In a war, there would be almost no working with the locals. Every man, woman, child may be willing to die for their government’s twisted cause.
Here’s why the heart doesn’t need to rest like other muscles

The guns may be old, but enough of them could wipe out the 25 million in Seoul in seconds.

(KCNA)

They’ll use their artillery aimed at Seoul.

Even a sports bookie who deals with hopeful Cleveland Browns fans would laugh at anyone who thinks North Korea stands the slightest chance against America. And for good reason: Their military is untrained, their troops are poorly equipped, and their technology is decades behind.

The real reason the U.S. hasn’t flexed its muscles since the 1950s is because of the large number of artillery guns pointed south, directly at one of our closest allies, South Korea. This threat has dangled for over sixty years and you can be certain they’re itching to pull the string.
Here’s why the heart doesn’t need to rest like other muscles

On the bright side, Korea would be reunified just like they always wanted… Just not in the way they’d hoped.

(KCNA)

They would go out in a blaze of glory.

There’s nowhere to go and there’s very little chance of winning. Their only support, China, is far more dependant on the United States than it is on them. The majority of their citizens are willing to lay down their lives for their leader — and North Korea knows it.

If they were to truly go up against America, they wouldn’t hold anything back. Winning is impossible, so their goal would be to leave as big of a dent on the way out as possible.
MIGHTY TACTICAL

The Army’s ‘Space Cowboys’ can see anywhere

It can sometimes be hard for commanders to get a full picture of the battlefield, whether that’s on the ground in Syria or in the forests of Colorado. The “Space Cowboys” of the Colorado Army National Guard‘s 117th Space Battalion aim to solve that problem.


Just the Facts

  • The 117th Space Battalion is the only unit of its kind in the National Guard.
  • Its 12 space support teams work with commercial and classified space-based assets to support command requirements.
  • The 117th has the highest concentration of space support teams anywhere in the Army.
  • Army Space Support Teams are made up of six soldiers — two officers and four enlisted — each with unique skills. The teams deploy around the world to enhance intelligence and operations planning abilities.
  • Here’s why the heart doesn’t need to rest like other muscles

    U.S. Army Sgt. Rick D. Peevy, a crew chief from Alpha Company, 2nd Battalion, 135th Aviation Regiment, Colorado Army National Guard, surveys the scene while wildfires burn the training range at Fort Carson, Colo., June 12, 2008.

  • “The [space] support team allows the warfighter to see and overcome enemy forces using the most appropriate amount of lethality available to them,” said Army Sgt. Maj. Fred Korb, the 117th’s senior enlisted leader. “For example, this allows the maximum effectiveness for targeting enemy forces while limiting danger to the coalition warfighter and noncombatants.”
  • More than 55 percent of soldiers in the unit have advanced degrees.
  • “Support can include producing imagery products, deconflicting GPS issues, missile warning, missile defense, satellite communications, and space as well as terrestrial weather effects on operations,” said Army Staff Sgt. Joseph Fauskee, the noncommissioned officer in charge of one of the battalion’s space support teams.
  • The 117th’s soldiers also produce the imagery needed to support wildfire fighting efforts in their home state. This year, some of its soldiers responded to the Spring Creek fire, the third-largest wildfire in Colorado history.
  • This article originally appeared on the United States Department of Defense. Follow @DeptofDefense on Twitter.

    MIGHTY CULTURE

    The “Shark Attack” was part of an outdated and costly training doctrine

    Earlier this month, Fort Benning’s United States Army Infantry School (USAIS) announced its plan to retire the “shark attack”, an approach unleashed on fresh recruits during their first moments at basic combat training. Headlines and critics would have you believe that the Army’s decision to eliminate this tactic from the basic training experience represents a move to make the training ‘nicer,’ ‘easier’ or ‘softer’ on recruits. But the truth is that the “shark attack” is outdated, ineffective and likely does more harm than good in the long run; Its retirement is long overdue.

    The “shark attack” is a purposeful stress-inducing attack on a single recruit that is carried out by several drill sergeants. It is typically marked by intense yelling, the issuing of contradicting commands and verbal denigration and is designed to assess the trainee’s ability to handle stress. According to Command Sergeant Major Robert K. Fortenberry, Command Sergeant Major for USAIS, the “shark attack” was designed to create a “chaotic environment that centered around applying physical exertion under stress.”


    Here’s why the heart doesn’t need to rest like other muscles

    Sgts. 1st Class Alec Donahoe and Todd Owen, drill sergeants with the Mississippi National Guard Recruiting and Retention Battalion, motivate a warrior in the Recruit Sustainment Program during a “shark attack” Oct. 7, 2017, in Senatobia. (U.S. National Guard photo by Staff Sgt. Scott Tynes)

    In a video articulating the new USAIS approach, CSM Fortenberry explains that this weeding-out technique is outmoded due in large part to the fact that we have an all-volunteer force. In other words, volunteer recruits likely already have attributes favorable for military service and don’t need to be thinned by the extreme technique which was used to “establish dominance and authority using intimidation and fear to weed out the weak of heart.”

    In truth, Army basic training techniques haven’t evolved much since the 1970s and in some cases since the early 20th century. The majority of the core training techniques are designed to reinforce blind obedience and reactiveness to commands. While making sure soldiers are able to follow orders is critical, modern warfare requires soldiers who are adept at, say, reading the mood of a marketplace in a foreign city versus going “over the top” or charging machine gun emplacements.

    The Army Vision for 2028, which was announced in June of this year and is co-authored by Army Chief of Staff General Mark Milley and Secretary of Defense Mark Esper, then Secretary of the Army, outlines a stark evolution of the U.S. Army’s battle stance. In addition to increasing the Army to 500,000 soldiers, the memo outlines the increased use of “autonomous systems, artificial intelligence and robotics” on a battle stage of “high-intensity conflict, with emphasis on operating in dense urban terrain, electronically degraded environments, and under constant surveillance.”

    Getting rid of the “shark attack” is, in fact, just one way the Army is modernizing its approach to preparing a modern fighting force. The retooling of infantry One Station Unit Training, or OSUT, also serves as the introduction of a new program dubbed ‘The First 100 Yards.’ According to CSM Fortenberry, the program builds a “critical foundation” by “professionally introducing the soldiers to the spirit of our great branch” and introducing drill sergeants as “leaders willing to share in the hardship.” The goal of The First 100 Yards is to “develop teamwork, identify informal leadership, establish trust, and build esprit de corps,” explained Fortenberry.

    But removing the “shark attack” isn’t just about modernizing training, but removing the vestiges of the hand-me-down era of training that was preoccupied with spitting out bonafide soldiers as quickly as possible. Late last year, USAIS announced its plans to extend OSUT from 14 to 22 weeks. The extension is intended to give recruits more exposure to weapons systems and small-unit and individual skills in a less pressurized, hurried training environment.

    But the OSUT extension is also a nod to how the military has had to evolve to accommodate the level of preparedness of incoming would-be soldiers. In a press release around the announcement of the new 22-week OSUT program, Colonel Dave Voorhies, 198th Infantry Brigade commander said the extension is geared toward establishing “firmer training fundamentals: marksmanship, physical training, land navigation, the ability to medicate, combat lifesaver skills, combat water survival, Soldier discipline, and more.” The extended OSUT allows for more time for soldiers to get up to Army standards while adequately preparing them for a faced-paced, technologically advanced battlefield.

    Attrition among recruits is a perennial problem for initial training facilities like USAIS. According to recent reports, attrition rates across the Army training centers fall somewhere around 12-15%, a number that comes at a huge price tag. A study of Army retention published in 2020 by the Rand Corporation, suggests that the total sunk cost for a single enlistment — including outlays for training, wages, and other benefits given to recruits — is roughly ,000. This equates to a loss of roughly 0 million dollars annually.

    According to a January report from Stars and Stripes, attrition rates of extended OSUT courses have fallen to below 6%, and on average, posted higher fitness scores than those from the 14-week course.

    Training centers like USAIS also have to contend with new reports that link post-traumatic stress and anxiety to the heavy-handed methods often used in basic training, especially tactics like the “shark attack.” And while the induction of stress and anxiety into training scenarios has always been seen as a crucial element to preparedness, methods like the “shark attack” may not have that effect, especially on a green volunteer looking to serve their country. In fact, it “betrays the innate trust between teammates,” said CSM Fortenberry. “And worse — betrays the crucial bond of trust with our leaders.”

    Here’s why the heart doesn’t need to rest like other muscles

    U.S. Army Drill Sergeant Sgt 1st Class. Aleman assigned to Foxtrot 1st Battalion 34th Infantry Regiment participates in the “Shark Attack” or fear stage of the discipline process, as trainees arrive to the First day of Basic Combat Training on 12 June 2017 at Fort Jackson, SC. (U.S. Army photo by Spc. Darius Davis/Released).

    That breakdown of trust may prove to stick with soldiers long after they have left the training world. According to the American Institute of Stress, basic training environments which teach soldiers ’emotional numbing’ may in fact be unknowingly laying the foundation for PTSD. “Emotional numbing,” it states, “allows for the person to put aside feelings and do whatever it takes to survive or help others survive.” While this is, at face value, a positive trait for a soldier to have on the battlefield, it’s often that it remains as the mode of dealing with any stressors.

    “Later such numbing may include a sense of not really being a person, feelings of not fitting in, that no one can understand, feeling or being told that one has no emotions, and not being able to feel emotions in situations calling for intimacy, tenderness, sexuality or grief. Efforts to avoid thoughts or feelings associated with the trauma may include isolating, substance abuse (drugs, alcohol, food, cigarettes), and other compulsive behaviors,” the report states.

    Essentially, the “shark attack” may be a cornerstone of a training approach that has been pre-conditioning soldiers to manage their military-related stress through ‘mental numbing.’ This ‘mental numbing’ may then lead soldiers to suppress subsequent feelings of stress that arise from combat scenarios which could exacerbate the effects of COS — Combat Operational Stress — and lead to permanent patterns of PTSD. In short, there is no basic ‘un-training.’

    Interestingly, the rate of PTSD among veterans since Vietnam has been fairly consistent. According to information from the Veterans Administration, roughly 15% of Vietnam veterans were diagnosed with PTSD resulting from combat service. That number was slightly lower in the Gulf War at 12%. For OIF and OEF, the amount of service-connected PTSD ranges from 11-20% year to year. There are a multitude of factors that contribute to PTSD. Further, the three aforementioned wars were markedly different in just about every aspect. That said, they all shared a common trait: the basic training doctrine.

    Without further study into the relationship of the “shark attack” style training in basic training units and its long term effects on PTSD, it’s impossible to know if the two are connected. What is certain, however, is that the new approach ushered in by USAIS is a positive one, if only because it does away with the outdated training modules of a long-extinct type of warfare and refocuses on the needs of today’s soldiers to fight today’s battles.

    This article originally appeared on SOFREP. Follow @sofrepofficial on Twitter.


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