How Short-Form Video Is Changing Your Brain

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Today’s Health Upgrade

• How short-form video is stealing your focus (and how to get it back)

• Your reaction time is slowing down. This mineral could help.

• Do plant proteins build muscle?

• The science on soy has changed (An inside look at hormones and inflammation)

Health 
Is Your Phone Training Your Brain to Be Distracted?

Most people know scrolling TikTok isn’t the best habit or use of time. But what's less obvious is what it's doing to your ability to focus on anything that actually matters.

A new meta-analysis of nearly 100,000 people found that the more you watch short-form videos, the more likely you are to struggle with attention and cognitive control, the mental brakes that help you stay on task and resist distractions.

Researchers analyzed 71 studies examining how platforms such as TikTok, Instagram Reels, and YouTube Shorts relate to cognitive function and mental health in youth and adult populations. The scientists found that watching short-form videos affects your ability to stop impulses and redirect focus. And it had a negative effect on mental health, specifically increasing stress and anxiety.

The researchers believe the problem starts with what makes the videos addictive in the first place: algorithmic conditioning. Short-form videos are engineered for rapid-fire reward. Every few seconds, you get something new. 

Researchers believe that repeated exposure to that pace may recalibrate your brain's expectations, making slower, more effortful tasks — reading, problem-solving, staying in the gym without your phone — feel increasingly difficult to sustain.

It’s worth noting that nearly all of the included studies were cross-sectional, meaning researchers captured a snapshot in time. That means we can't say short-form video causes these effects. It's possible that people with existing attention difficulties are simply drawn to that type of content. But a consistent pattern across almost 100,000 people is hard to dismiss.

The practical implication doesn't necessarily require deleting apps. But it does suggest making a change. Start with context-specific limits, such as cutting off short-form videos before workouts, during focused work, and in the hour before bed. Both iOS and Android have built-in screen time tools that take about two minutes to set up. That's the minimum effective dose here: protect the windows that matter most, and then build from there. 

Together With Magtein
Are You Slowing Down In Ways You Don’t Notice?

Most people don’t even think about reaction time. It seems like a benefit that only matters if you're a competitive gamer or a fighter pilot. But reaction time shows up in subtle ways that matter a lot. 

Consider the last time you had to slam on the brakes because someone cut you off. Or lunged to protect your kid before they hit their head on the counter. 

Your ability to see something and respond — fast and accurately — is one of those invisible skills you rely on dozens of times a day without thinking about it. Most people use caffeine to boost their reaction time, but research suggests there may be a non-stimulant approach.

If you’re worried about fighting the inevitable slowdown, scientists found that six weeks of Magtein (magnesium L-threonate) improved reaction time and hand-eye coordination in a controlled study.

Researchers had adults complete a test in which they rapidly click on appearing targets, assessing visual processing speed, motor response, and coordination. After six weeks, the Magtein group's scores improved significantly. The placebo group? No change at all.

As we age, reaction time naturally slows by about 5 to 10% per decade after 30, increasing the risk of falls and driving accidents.

The likely mechanism involves magnesium's role in cleaning up neural signaling. By reducing background "noise" in the brain and supporting faster transmission across the visual-motor pathway, reaction time improves. Not because you're stimulated, but because your nervous system is running more efficiently.

The researchers note that this is the first controlled trial to show that any form of magnesium improves visuomotor performance. For anyone who values staying sharp and responsive — whether you're on a court, behind a wheel, or chasing a toddler — this is a finding worth filing away.

As an added bonus, the same study’s primary outcome found that Magtein improves HRV, which is a measure of your body's ability to shift into recovery mode.

As a result, participants felt less impaired by their sleep, even though they weren't sleeping longer. Their nervous systems were recovering more efficiently during the same hours.

If you’re looking to add Magtein to your routine, Momentous Magtein is our preferred supplement because it’s backed by the Momentous Standard, which ensures third-party testing, quality checks, and purity. 

To learn more about the science behind magnesium l-threonate and the ground-breaking reaction time and HRV research, visit magtein.com.

Judge The Headline 
“Soy Protein Is An Inferior Protein”

There's a version of the protein conversation that stops at "animal protein is better," and nobody ever digs any deeper. And while earlier research suggested that plants were inferior, more recent studies paint a more nuanced picture, especially when it comes to soy.

A 2025 meta-analysis of 43 randomized controlled trials found that soy protein produces comparable muscle gains to dairy protein. If you've been avoiding soy because someone told you it's a poor muscle-building protein, the evidence says otherwise.

Researchers reviewed randomized controlled trials comparing plant and animal protein sources in relation to muscle mass, strength, and physical performance. Overall, plant protein led to slightly less muscle mass, but this headline finding overlooked an important point. 

When soy was compared directly against milk protein across 17 trials, the difference essentially disappeared. The gap in the broader analysis was driven by single-source proteins such as rice, oat, chia, and potato, which showed a greater disadvantage relative to animal protein.

Not to mention, strength and physical performance showed no significant differences across any group, regardless of protein source. In adults 60 and older, even the small muscle mass gap between plant and animal protein was no longer statistically significant, suggesting that for this age group, hitting your daily protein target matters considerably more than where it comes from.

It's worth noting that the research tested soy protein supplements, not specifically foods like tofu, edamame, or tempeh. That said, whole-food soy-based foods have meaningful protein quality on their own. Soy is a complete protein, containing all nine essential amino acids.

Research on protein quality scoring across 45 sources confirms that the majority of soy products have high absorption (based on gold-standard DIAAS scores), and a controlled digestibility study measuring amino acid absorption found tofu to be approximately 95% digestible, which is comparable to animal protein sources. The key functional difference from dairy is lower leucine content, not a fundamental deficiency in quality.

Like any dietary decision, what you eat is your choice. You don’t need to eat soy, and you can avoid it if you feel that’s the best choice for you. With any diet, getting some variety from your protein sources is a good idea. But if soy protein is part of your diet — whether from a supplement or whole food sources like edamame and tofu — the evidence suggests you're not meaningfully leaving muscle gains on the table.

Fact or Fiction
Beyond Muscle: But Is Soy Healthy?

When we’ve posted in the past about soy, we’ve heard the concerns about soy extending beyond the gym, and you deserve a direct answer. 

If you’re worried that soy is bad for your health, overall, the research suggests something very different from the fear spread on social media. 

The most comprehensive analysis of the clinical data focused on male hormonal health — 41 studies involving over 1,700 men — found that neither soy protein nor isoflavone intake affects testosterone, free testosterone, or estrogen levels at normal dietary amounts, a finding that held regardless of dose or study duration. 

But it’s not just hormones. On prostate health, the evidence leans in a direction that might surprise people who've avoided soy. Multiple systematic reviews show either a protective or neutral association between soy isoflavone intake and prostate cancer risk, with no credible controlled trial evidence of harm at typical intakes.

The data on cardiovascular health isn’t much different. Soy protein is associated with improvements in LDL cholesterol and is recognized in FDA-authorized health claims for its relationship to reduced risk of coronary heart disease. 

There are those who say soy increases inflammation. However, a meta-analysis of 24 randomized controlled trials found that soy supplementation significantly reduced CRP concentrations, while a separate meta-analysis of 31 RCTs found that soy protein produced a significant reduction in circulating a common blood measure of inflammation (TNF-α levels). 

Some other studies are hypothetical, mechanistic, tested in animals, or done at levels that don’t reflect real human consumption.

Again, you can eat soy or avoid it. Do what feels right for you. But the available evidence doesn't support the claim that soy causes negative hormonal or inflammatory effects at the amounts people would realistically consume, and across several health markers beyond muscle, it points in a favorable direction.

Editor’s Note: Is there a headline or story you’d like us to review? Simply hit reply to this email (it’s us on the other end), and send us a link or headline you’ve seen that you want us to investigate.

The Positive Corner of The Internet
About Arnold’s Pump Club Editorial Standards

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Publisher: Arnold Schwarzenegger​

Editors-in-chief: Adam Bornstein and Daniel Ketchell