HEALTH

Weekender

What happens to you in isolation

SINCE the pandemic officially began in March, we’ve been told staying home is the best way to avoid catching Covid-19.
And it is. But life in confinement can cause physical ailments on its own.
Being homebound for so long contorts the body, weakens the heart and lungs and even impairs brain function. The effects of life in isolation may stay with us beyond the pandemic’s end (whenever that may be).
This is what half a year of isolation, staying home and staying sedentary can do to your body.

You start losing muscle
A week homebound, whether you’re working, eating or sleeping, may feel comforting and necessary. But all the inactivity can undo hard-won progress.
That’s because it can take months to build muscle and just one week to lose it. Humans, for all of our hardiness, also lose muscle more quickly the older we get, said Keith Baar, a professor of molecular exercise physiology at the University of California – Davis.
When you lose muscle, you’re not necessarily losing bulk, but you are losing strength, which Baar said is one of the “strongest indicators” of how long you’ll live.
“The stronger we stay, the easier it is for us to maintain our longevity.”

Your heart and lungs get weaker
If you’re not exercising, you’re not raising your heart rate. And when your heart isn’t pumping as hard, it gets weaker, Baar said.
The same thing happens to your lungs when you’re inactive, said Dr. Panagis Galiatsatos, a pulmonologist from Johns Hopkins Bayview Medical Center. He said many of his patients have felt their breathing function deteriorate because they’re no longer conditioned to exercise.
People with poor lung health are already considered more susceptible to coronavirus because it’s a respiratory illness, so they’re likely staying home to reduce their risk of infection. But if they’re not moving and increasing blood flow to their lungs, then their preexisting condition might harm them anyway.
Exercise is the only key to improve both heart and lung function — “Not a single medication can do that,” Galiatsatos said. If it’s not safe to leave the house, Baar recommends dancing or finding household objects for home strength training — think milk jug deadlifts.

You gain fat
If you’re home all day, every day, you’re likely feet away from your pantry. Depending on your perspective, that’s either convenient or dangerous.
With such easy access, your “feeding” window, or the period of time during which you eat most of your meals, might widen from 10 or 12 hours every day to 15 hours a day– more than half the day, which could cause your insulin levels to spike. Insulin encourages fat storage and converting other fat molecules to fat, said Giles Duffield, an associate professor of anatomy and physiology at the University of Notre Dame who studies circadian rhythms and metabolism, among other subjects.
Excessive eating is also an issue because, at the beginning of the pandemic, many people stocked up on nonperishable foods in case of supply shortages, Duffield said. Many nonperishable foods are highly processed and rich in sugars and starches.
Weight gain during periods of intense stress is normal, and 2020 has been unrelentingly stressful. Weight gain becomes dangerous, though, when it turns into obesity. Then, your body might start to resist insulin, and chronic health issues like metabolic illness or diabetes may develop, Duffield said.

Your posture is affected
We all have a seated position we subconsciously sink into — slumped forward, shoulders hunched; spine curled, neck bent; on your chest, elbows up.
But sitting and lying down all day can seriously affect your posture and strain your back, neck, shoulders, hips and eyes, said Brandon Brown, an epidemiologist and associate professor in the Center for Healthy Communities at the University of California – Riverside.
Brown suggests getting up from your seat once an hour, walking around and stretching for a moment. You might even lie on the floor and “let your back readjust,” he said.

Your sleep suffers
At least half of all Americans are skimping on vitamin D, which sustains bone density and keeps fatigue at bay. You’re definitely one of them if you spend most of your day at home, curtains drawn, Duffield said.
Getting enough sunlight in the morning helps synchronize your body’s circadian rhythm, Duffield said. So if you’re shut in all week or working in the dark, your sleep might suffer, too.
Brown said as long as you’re going on walks or exercising, doing yard work or other activities that drag you outside for a bit, you won’t need to worry about getting enough sunlight. If you’re unable to get out of the house or the weather won’t permit you to, an artificial bright light can help your body retune in the morning, Duffield said, as can avoiding blue lights at night.

Your brain slows
A sedentary lifestyle can slow your brain, too.
Exercise produces certain chemicals in the brain that break down toxins in the blood and even prevent them from going to the brain, where they can kill brain cells, Baar said.
Not exercising means you won’t as efficiently break down amino acid byproducts that wind up as neurotoxins in the brain.
The effects of isolation are insidious — like the pandemic, the physical symptoms after months of seclusion often aren’t obvious until they become harmful or extreme.
It’s possible, too, to stave off those symptoms before they set in for good.
Prioritizing your mental and physical health while staying home requires some work, but it’s a healthier coping mechanism for uncertainty than staying stationary until Covid-19 is no longer a threat, health experts say. And when it’s safe to live fully again, you’ll be prepared. -CNN


Fatigue control fatigue possible

SCIENTISTS at Johns Hopkins Medicine using MRI (magnetic resonance imaging) scans and computer modeling say they have further pinpointed areas of the human brain that regulate efforts to deal with fatigue.
The findings, they say, could advance the development of behavioral and other strategies that increase physical performance in healthy people, and also illuminate the neural mechanisms that contribute to fatigue in people with depression, multiple sclerosis and stroke.
Results of the research were published online Aug 12 in Nature Communications.
“We know the physiologic processes involved in fatigue, such as lactic acid build-up in muscles, but we know far less about how feelings of fatigue are processed in the brain and how our brain decides how much and what kind of effort to make to overcome fatigue,” says Vikram Chib, Ph.D., assistant professor of biomedical engineering at the Johns Hopkins University School of Medicine and research scientist at the Kennedy Krieger Institute.
Knowing the brain regions that control choices about fatigue-moderating efforts can help scientists find therapies that precisely alter those choices, says Chib. “It might not be ideal for your brain to simply power through fatigue,” says Chib. “It might be more beneficial for the brain to be more efficient about the signals it’s sending.”
For the study, Chib first developed a novel way to objectively quantify how people “feel” fatigue, a difficult task because rating systems can vary from person to person. Physicians often ask their patients to rate their fatigue on a scale of 1 to 7, but like pain scales, such ratings are subjective and varied.
To standardise the metric for fatigue, Chib asked 20 study participants to make risk-based decisions about exerting a specific physical effort. The average age of participants was 24 and ranged from 18 to 34. Nine of the 20 were female.
The 20 participants were asked to grasp and squeeze a sensor after training them to recognize a scale of effort. For example, zero was equal to no effort and 50 units of effort were equal to half the participant’s maximum force. The participants learned to associate units of effort with how much to squeeze, which helped to standardize the effort level among individuals.
The participants repeated the grip exercises for 17 blocks for 10 trials each, until they were fatigued, then were offered one of two choices for making each effort. One was a random (“risky”) choice based on a coin flip, offering the chance to exert no effort or a predetermined effort level. The other choice was a predetermined set effort level. By introducing uncertainty, the researchers were tapping in to how each subject valued their effort — a way, in effect, of shedding light on how their brains and minds decided how much effort to make.
Based on whether the participant chose a risky option versus the predetermined one, the researchers used computerized programs to measure how participants felt about the prospect of exerting particular amounts of effort while they were fatigued.
“Unsurprisingly, we found that people tend to be more risk averse — to avoid — effort,” says Chib. Most of the participants (19 of 20) opted for the risk-free choice of a predetermined effort level. This means that, when fatigued, participants were less willing to take the chance of having to exert large amounts of effort.
“The predetermined amount had to get pretty high in relative effort for participants to choose the coin toss option,” says Chib.
Among a separate group of 10 people trained on the gripping system but not given numerous, fatiguing trials, there was no significant tendency toward picking either the risky coin toss or defined effort.
Chib’s research team also evaluated participants’ brain activity during the gripping exercises using functional magnetic resonance imaging (fMRI) scans, which track blood flow through the brain and show which neurons are firing most often.
Chib’s team confirmed previous findings that brain activity when participants chose between the two options seemed to increase in all participants in an area of the brain’s known as the insula.
Also using MRI scans, they took a closer look at the motor cortex of the brain when the participants were fatigued. This region of the brain is responsible for exerting the effort itself.
The researchers found that the motor cortex was deactivated at the time participants “decided” between the two effort choices. That finding is consistent, Chib says, with previous studies showing that when people perform repeated fatiguing exertions, motor cortex activity is decreased, associated with fewer signals being sent down to the muscles.
Participants whose motor cortex activity changed the least, in response to fatiguing exertion, were the ones who were most risk averse in their effort choices and were most fatigued. This suggests that fatigue might arise from a miscalibration between what an individual thinks they are able to achieve and the actual activity in motor cortex.
Essentially, the body attunes to the motor cortex when fatigued, because if the brain kept sending more signals to muscles to act, physiological constraints would begin to take over, for example, increased lactic acid, contributing to even more fatigue. – Science Daily

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