By Joanna Fong-Isariyawongse, University of Pittsburgh 

If you have ever lifted a weight, you know the routine: challenge the muscle, give it rest, feed it and repeat. Over time, it grows stronger.

Of course, muscles only grow when the challenge increases over time. Continually lifting the same weight the same way stops working.

It might come as a surprise to learn that the brain responds to training in much the same way as our muscles, even though most of us never think about it that way. Clear thinking, focus, creativity and good judgment are built through challenge, when the brain is asked to stretch beyond routine rather than run on autopilot. That slight mental discomfort is often the sign that the brain is actually being trained, a lot like that good workout burn in your muscles.

Think about walking the same loop through a local park every day. At first, your senses are alert. You notice the hills, the trees, the changing light. But after a few loops, your brain checks out. You start planning dinner, replaying emails or running through your to-do list. The walk still feels good, but your brain is no longer being challenged.

Routine feels comfortable, but comfort and familiarity alone do not build new brain connections.

As a neurologist who studies brain activity, I use electroencephalograms, or EEGs, to record the brain’s electrical patterns.

Research in humans shows that these rhythms are remarkably dynamic. When someone learns a new skill, EEG rhythms often become more organized and coordinated. This reflects the brain’s attempt to strengthen pathways needed for that skill.

Your brain trains in zones too

For decades, scientists believed that the brain’s ability to grow and reorganize, called neuroplasticity, was largely limited to childhood. Once the brain matured, its wiring was thought to be largely fixed.

But that idea has been overturned. Decades of research show that adult brains can form new connections and reorganize existing networks, under the right conditions, throughout life.

Some of the most influential work in this field comes from enriched environment studies in animals. Rats housed in stimulating environments filled with toys, running wheels and social interaction developed larger, more complex brains than rats kept in standard cages. Their brains adapted because they were regularly exposed to novelty and challenge.

Human studies find similar results. Adults who take on genuinely new challenges, such as learning a language, dancing or practicing a musical instrument, show measurable increases in brain volume and connectivity on MRI scans.

The takeaway is simple: Repetition keeps the brain running, but novelty pushes the brain to adapt, forcing it to pay attention, learn and problem-solve in new ways. Neuroplasticity thrives when the brain is nudged just beyond its comfort zone.

The reality of neural fatigue

Just like muscles, the brain has limits. It does not get stronger from endless strain. Real growth comes from the right balance of challenge and recovery.

When the brain is pushed for too long without a break – whether that means long work hours, staying locked onto the same task or making nonstop decisions under pressure – performance starts to slip. Focus fades. Mistakes increase. To keep you going, the brain shifts how different regions work together, asking some areas to carry more of the load. But that extra effort can still make the whole network run less smoothly.

Neural fatigue is more than feeling tired. Brain imaging studies show that during prolonged mental work, the networks responsible for attention and decision-making begin to slow down, while regions that promote rest and reward-seeking take over. This shift helps explain why mental exhaustion often comes with stronger cravings for quick rewards, like sugary snacks, comfort foods or mindless scrolling. The result is familiar: slower thinking, more mistakes, irritability and mental fog.

This is where the muscle analogy becomes especially useful. You wouldn’t do squats for six hours straight, because your leg muscles would eventually give out. As they work, they build up byproducts that make each contraction a little less effective until you finally have to stop. Your brain behaves in a similar way.

Likewise, in the brain, when the same cognitive circuits are overused, chemical signals build up, communication slows and learning stalls.

But rest allows those strained circuits to reset and function more smoothly over time. And taking breaks from a taxing activity does not interrupt learning. In fact, breaks are critical for efficient learning.

The crucial importance of rest

Among all forms of rest, sleep is the most powerful.

Sleep is the brain’s night shift. While you rest, the brain takes out the trash through a special cleanup system called the glymphatic system that clears away waste and harmful proteins. Sleep also restores glycogen, a critical fuel source for brain cells.

And importantly, sleep is when essential repair work happens. Growth hormone surges during deep sleep, supporting tissue repair. Immune cells regroup and strengthen their activity.

During REM sleep, the stage of sleep linked to dreaming, the brain replays patterns from the day to consolidate memories. This process is critical not only for cognitive skills like learning an instrument but also for physical skills like mastering a move in sports.

On the other hand, chronic sleep deprivation impairs attention, disrupts decision-making and alters the hormones that regulate appetite and metabolism. This is why fatigue drives sugar cravings and late-night snacking.

Sleep is not an optional wellness practice. It is a biological requirement for brain performance.

Exercise feeds the brain too

Exercise strengthens the brain as well as the body.

Physical activity increases levels of brain-derived neurotrophic factor, or BDNF, a protein that acts like fertilizer for neurons. It promotes the growth of new connections, increases blood flow, reduces inflammation and helps the brain remain adaptable across one’s lifespan.

This is why exercise is one of the strongest lifestyle tools for protecting cognitive health.

Train, recover, repeat

The most important lesson from this science is simple. Your brain is not passively wearing down with age. It is constantly remodeling itself in response to how you use it. Every new challenge and skill you try, every real break, every good night of sleep sends a signal that growth is still expected.

You do not need expensive brain training programs or radical lifestyle changes. Small, consistent habits matter more. Try something unfamiliar. Vary your routines. Take breaks before exhaustion sets in. Move your body. Treat sleep as nonnegotiable.

So the next time you lace up your shoes for a familiar walk, consider taking a different path. The scenery may change only slightly, but your brain will notice. That small detour is often all it takes to turn routine into training.

The brain stays adaptable throughout life. Cognitive resilience is not fixed at birth or locked in early adulthood. It is something you can shape.

If you want a sharper, more creative, more resilient brain, you do not need to wait for a breakthrough drug or a perfect moment. You can start now, with choices that tell your brain that growth is still the plan.

About the Author: 

Joanna Fong-Isariyawongse, Associate Professor of Neurology, University of Pittsburgh

This article is republished from The Conversation under a Creative Commons license. Read the original article.

By Kaveh Madani, United Nations University 

The world is now using so much fresh water amid the consequences of climate change that it has entered an era of water bankruptcy, with many regions no longer able to bounce back from frequent water shortages.

About 4 billion people – nearly half the global population – live with severe water scarcity for at least one month a year, without access to sufficient water to meet all of their needs. Many more people are seeing the consequences of water deficit: dry reservoirs, sinking cities, crop failures, water rationing and more frequent wildfires and dust storms in drying regions.

Water bankruptcy signs are everywhere, from Tehran, where droughts and unsustainable water use have depleted reservoirs the Iranian capital relies on, adding fuel to political tensions, to the U.S., where water demand has outstripped the supply in the Colorado River, a crucial source of drinking water and irrigation for seven states.

Water bankruptcy is not just a metaphor for water deficit. It is a chronic condition that develops when a place uses more water than nature can reliably replace, and when the damage to the natural assets that store and filter that water, such as aquifers and wetlands, becomes hard to reverse.

A new study I led with the United Nations University Institute for Water, Environment and Health concludes that the world has now gone beyond temporary water crises. Many natural water systems are no longer able to return to their historical conditions. These systems are in a state of failure – water bankruptcy.

What water bankruptcy looks like in real life

In financial bankruptcy, the first warning signs often feel manageable: late payments, borrowed money and selling things you hoped to keep. Then the spiral tightens.

Water bankruptcy has similar stages.

At first, we pull a little more groundwater during dry years. We use bigger pumps and deeper wells. We transfer water from one basin to another. We drain wetlands and straighten rivers to make space for farms and cities.

Then the hidden costs show up. Lakes shrink year after year. Wells need to go deeper. Rivers that once flowed year-round turn seasonal. Salty water creeps into aquifers near the coast. The ground itself starts to sink.

That last one, subsidence, often surprises people. But it’s a signature of water bankruptcy. When groundwater is overpumped, the underground structure, which holds water almost like a sponge, can collapse. In Mexico City, land is sinking by about 10 inches (25 centimeters) per year. Once the pores become compacted, they can’t simply be refilled.

The Global Water Bankruptcy report, published on Jan. 20, 2026, documents how widespread this is becoming. Groundwater extraction has contributed to significant land subsidence over more than 2.3 million square miles (6 million square kilometers), including urban areas where close to 2 billion people live. Jakarta, Bangkok and Ho Chi Minh City are among the well-known examples in Asia.

Agriculture is the world’s biggest water user, responsible for about 70% of the global freshwater withdrawals. When a region goes water bankrupt, farming becomes more difficult and more expensive. Farmers lose jobs, tensions rise and national security can be threatened.

About 3 billion people and more than half of global food production are concentrated in areas where water storage is already declining or unstable. More than 650,000 square miles (1.7 million square kilometers) of irrigated cropland are under high or very high water stress. That threatens the stability of food supplies around the world.

Droughts are also increasing in duration, frequency and intensity as global temperatures rise. Over 1.8 billion people – nearly 1 in 4 humans – dealt with drought conditions at various times from 2022 to 2023.

These numbers translate into real problems: higher food prices, hydroelectricity shortages, health risks, unemployment, migration pressures, unrest and conflicts.

How did we get here?

Every year, nature gives each region a water income, depositing rain and snow. Think of this like a checking account. This is how much water we receive each year to spend and share with nature.

When demand rises, we might borrow from our savings account. We take out more groundwater than will be replaced. We steal the share of water needed by nature and drain wetlands in the process. That can work for a while, just as debt can finance a wasteful lifestyle for a while.

Those long-term water sources are now disappearing. The world has lost more than 1.5 million square miles (4.1 million square kilometers) of natural wetlands over five decades. Wetlands don’t just hold water. They also clean it, buffer floods and support plants and wildlife.

Water quality is also declining. Pollution, saltwater intrusion and soil salinization can result in water that is too dirty and too salty to use, contributing to water bankruptcy.

Climate change is exacerbating the situation by reducing precipitation in many areas of the world. Warming increases the water demand of crops and the need for electricity to pump more water. It also melts glaciers that store fresh water.

Despite these problems, nations continue to increase water withdrawals to support the expansion of cities, farmland, industries and now data centers.

Not all water basins and nations are water bankrupt, but basins are interconnected through trade, migration, climate and other key elements of nature. Water bankruptcy in one area will put more pressure on others and can increase local and international tensions.

What can be done?

Financial bankruptcy ends by transforming spending. Water bankruptcy needs the same approach:

• Stop the bleeding: The first step is admitting the balance sheet is broken. That means setting water use limits that reflect how much water is actually available, rather than just drilling deeper and shifting the burden to the future.
• Protect natural capital – not just the water: Protecting wetlands, restoring rivers, rebuilding soil health and managing groundwater recharge are not just nice-to-haves. They are essential to maintaining healthy water supplies, as is a stable climate.

• Use less, but do it fairly: Managing water demand has become unavoidable in many places, but water bankruptcy plans that cut supplies to the poor while protecting the powerful will fail. Serious approaches include social protections, support for farmers to transition to less water-intensive crops and systems, and investment in water efficiency.
• Measure what matters: Many countries still manage water with partial information. Satellite remote sensing can monitor water supplies and trends, and provide early warnings about groundwater depletion, land subsidence, wetland loss, glacier retreat and water quality decline.
• Plan for less water: The hardest part of bankruptcy is psychological. It forces us to let go of old baselines. Water bankruptcy requires redesigning cities, food systems and economies to live within new limits before those limits tighten further.

With water, as with finance, bankruptcy can be a turning point. Humanity can keep spending as if nature offers unlimited credit, or it can learn to live within its hydrological means.

About the Author: 

Kaveh Madani, Director of the Institute for Water, Environment and Health, United Nations University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

By D. Brian Blank, Mississippi State University and Brandy Hadley, Appalachian State University 

After months of speculation, President Donald Trump nominated Kevin Warsh on Jan. 30, 2026, to be the next chair of the Federal Reserve.

If confirmed by Congress, Warsh will inherit leadership of the U.S. central bank at a delicate time. For months, current Fed Chair Jerome Powell has come under attack from the Trump administration for failing to heed the president’s call for lower interest rates. The fight has put into question the central bank’s independence and its role in stewarding the economy.

Powell’s term as chair will end in mid-May, leaving his successor to navigate an economy that has improved on some fronts but remains uneven and uncertain.

But what should America expect from the next Fed chair? Here are three things to note about Trump’s nominee.

1. He is a familiar face …

Warsh brings deep experience with monetary policymaking to the role.

A graduate of Stanford University and Harvard Law School, he served as special assistant to the president for economic policy and executive secretary of the White House National Economic Council under President George W. Bush before becoming one of the youngest members of the Federal Reserve Board of Governors.

Warsh is no newcomer to discussions about Federal Reserve leadership. He was a finalist for the job in 2017, when Trump instead appointed Powell. Trump has since stated that he made a mistake by not selecting Warsh then – though clashes between Trump and Powell may have influenced that view.

Warsh’s credentials are unquestionable. As a governor of the Federal Reserve Board from 2006 to 2011, he worked closely with other policymakers and with Wall Street during the global financial crisis of 2008. Since departing the Fed, he has returned to Stanford as a visiting fellow at the Hoover Institution and a lecturer at the Graduate School of Business, as well as a member of the Panel of Economic Advisers of the Congressional Budget Office.

He also has ties to the finance industry. He began his career in mergers and acquisitions at Morgan Stanley and, since leaving the Fed, has worked as a partner at Duquesne Family Office, an investment firm that manages the personal wealth of hedge fund manager Stanley Druckenmiller and other investors.

In 2016, Trump included Warsh in an economic advisory group assembled during his transition. Critics of Warsh’s nomination point toward his father-in-law, Ronald Lauder, a college friend and donor of the president, as evidence of politicization.

2. … with evolving monetary views

The big question people have is what a Warsh Fed would mean for monetary policy – that is, is it likely to play tight or loose with rates.

When the economy is growing quickly, like in 2021, the Federal Reserve tightens policy by raising interest rates to avoid the kind of economic growth that may not be sustainable long term and can lead to bubbles. However, during downturns, like in 2008 or 2020, the economic policy that can provide a backstop for the economy is looser. The Fed tends to lower rates in these situations, which supports growth.

Warsh’s views on monetary policy have long been considered hawkish, meaning he is inclined toward tighter policy and generally higher interest rates to keep inflation in check, even at the expense of slower economic growth. During his previous tenure at the Fed, he signaled concern about expansive monetary tools such as quantitative easing, in which the central bank buys Treasurys and other securities to stimulate the economy. This resulted in what Warsh called a “bloated” Fed balance sheet that held almost US$9 trillion of debt at its peak in 2022.

In recent public remarks leading up to his nomination, however, he has increasingly aligned in part with Trump’s push for lower interest rates and discussed establishing a new Treasury-Fed Accord, like in 1951, when Fed independence from fiscal authorities such as the Treasury Department was established.

3. His nod highlights fight over Fed independence

A central question surrounding this nomination is whether it promotes the politicization of the Federal Reserve.

The Fed’s independence from day-to-day political pressure has long been viewed as a cornerstone of U.S. economic policymaking. Decisions about interest rates, inflation control and financial stability are insulated from electoral politics for that reason. A truly independent Fed can resist making decisions that provide a short-term economic bump – something incumbent governments tend to like – but may lead to longer-term economic pain down the road.

The Fed tends to use its monetary policy tools carefully. Yet politicians tend to want looser monetary policy so the economy grows fast and they get credit for it.

And Warsh’s nomination can be seen in the context of a broader push from the executive branch to exert greater influence over monetary policy. Given Trump’s public criticism of Powell and vocal calls for his early departure, the president almost certainly intended to nominate someone who would lower interest rates according to preferences stated by the administration.

Critics of the nomination have argued that Warsh has a tendency to be more opportunistic with his policy views than Powell and other economists, who try to ignore political preferences.

As such, Warsh’s nomination encapsulates more than just a leadership transition. It highlights the ongoing tensions between political priorities and the traditional economic playbook, between short-term growth pressures and long-term stability, and between institutional independence and democratic accountability.

Time will tell whether he turns out to be hawkish or politically motivated as chair, if he is confirmed.

About the Author:

D. Brian Blank, Associate Professor of Finance, Mississippi State University and Brandy Hadley, Associate Professor of Finance and Distinguished Scholar of Applied Investments, Appalachian State University

This article is republished from The Conversation under a Creative Commons license. Read the original article.