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Today’s Health Upgrade

• Does this popular supplement cause heart failure?

• What keeps you up at night

• The truth about eating the same foods and your gut health

• Why workout recovery might feel slow

Beyond The Headline 
Melatonin Doesn't Cause Heart Failure. But Your Use Still Might Be An Issue

If you’ve ever taken melatonin, you might have felt a bit of panic based on research suggesting you’re at a “90% higher risk of heart failure.” And if you ask AI to calm your fears, it probably didn’t help:

Before you react to that overview, like many of the headlines you see, all is not as it appears. That’s why we read the studies, take a deeper look at the data, and help you make sense of it all, so you can make an informed decision about what’s right for your goals and health.

First, let’s tackle your primary fear: Research does not suggest melatonin causes heart failure. 

The better question might be: if you've needed melatonin to fall asleep every night for a year, the finding that matters isn't that the supplement is dangerous. It's that it isn't working. But more on that in a moment.

The scary claim came from a conference presentation where researchers pulled 5 years of health records on adults with insomnia. They compared people with melatonin use for a year or more against people with no melatonin on record. 

Heart failure turned up in 4.6% of the melatonin group and 2.7% of the others. That’s the basis for the 90% figure, which is itself misleading.

But when we looked at all the data made available, we found something that didn't make the headlines: melatonin users were also about 3.5 times as likely to be hospitalized for heart failure and roughly twice as likely to die of any cause.

Those last two numbers are the sign that the association data is misleading because nothing on a drugstore shelf doubles your chance of dying in five years. 

When the association is that big across unrelated outcomes, the more likely explanation is who's taking the pill, not the pill itself. 

And when we read the commentary, the lead author even admitted worse insomnia, depression, or anxiety could be driving both the melatonin habit and the heart risk. 

Just because melatonin doesn’t deserve a red flag doesn’t mean it should be relied upon either. If melatonin is used at all, it’s most likely to help jet lag or a schedule flip. Outside of that, it doesn’t help sleep in the way you’ve been told.

A 2022 review of 24 randomized trials found it didn't meaningfully improve how quickly people fell asleep, how long they slept, or how well they slept. 

Not to mention, neither the American Academy of Sleep Medicine nor the American College of Physicians recommends it. 

If you've been leaning on it every single night for a year to fall asleep, the move isn't to panic about your heart. It's to treat that as a sign that something needs fixing, and to address the problems and causes, and search for better solutions that work. 

Together With Eight Sleep 
What's Really Keeping You Up At Night?

You might have read the last item and wondered, “If melatonin isn't the solution to my sleep problems, what is?” 

When researchers and sleep physicians line up the real causes of bad sleep, the list is boringly consistent: not enough time set aside to sleep, bedtimes that drift night to night, too little morning light, caffeine or alcohol that’s consumed too late, undiagnosed breathing problems, pain, stress, and the environment you sleep in. 

Fix or address any or all of those, and that’s the real “magic pill” to a better night of rest. 

It might seem like a lot, but there’s good news you shouldn’t ignore: most of the “science of better sleep” list is free. 

Lock in a consistent wake time every day of the week (including weekends). Get light in your eyes early in your day, and your melatonin production can naturally reset. Move your last coffee to before noon, and the caffeine will be out of your system. Get some exercise, and you’ll be more likely to feel tired at the end of the day and feel less stress. All of these tips will do more than any supplement. Start there before you spend a dollar.

Once you do that, there’s another variable that won’t bend to habits and will influence how quickly you fall asleep and how well you stay asleep: your sleep environment. 

To drop into deep sleep and stay there, your core temperature has to fall about a degree. A room that runs warm, or a bed that traps your heat, blocks that fall. That's why you drift off fine and then snap awake in the middle of the night. Or, you wake up feeling like you didn’t get enough deep sleep. 

Studies show the right mattress can help, and published research suggests the Pod by Eight Sleep is the best option. 

It's a cover that fits over the bed you already own, and it addresses your body temperature. It actively cools or heats each side from 55°F to 110°F and keeps adjusting on its own throughout the night as your body changes. Two people, two temperatures, no thermostat wars. And it reads your sleep straight from the cover, so there's nothing to wear.

The result is that studies have found that Pod users get up to 34% more deep sleep. If temperature is keeping you awake or disturbing you at night, this fix pinpoints exactly where the trouble is. 

As a Pump Club reader, you get up to $350 OFF the Eight Sleep Pod. And you get 30 days to try it at home and return it if you don't love it. If you have an HSA or FSA, the Pod may qualify as a medical expense through Truemed, and qualified customers save an average of about 30%. Check your eligibility here.

If sleep is a struggle, there are answers. Many of them are free. And if your mattress is holding you back, there’s a fix for that too. 

Whatever you do, stop wasting your time thinking melatonin is a cure, and start focusing on things that will make a difference you will see and feel. 

Instant Health Boost 
How Eating The Same Foods Influences Gut Health

You've got your meals. The same breakfast most mornings, the lunch you don't think twice about, a dinner rotation of maybe five things. But you might worry that all that repetition is shortchanging your gut health.

A new study says the fear is misdirected.

Researchers tracked adults who logged every meal in real time, and the ones who ate good food consistently, day after day, tended to have a more diverse gut, not less. The steady eaters had richer microbiomes than the inconsistent ones.

Scientists had 1,000 healthy adults log meals through an app for up to 4 weeks, then collected a single stool sample to analyze the mix of bacteria in their gut. 

The researchers found two common behaviors linked to a more diverse gut: Diet quality — such as more vegetables, fruit, nuts, fiber — was a leading indicator. That’s probably what you would expect. But the second one might be more surprising. People who ate the same healthy foods day after day had more gut diversity than those who were inconsistent.

The researchers think of the gut like an ecosystem. A reliable food supply lets more bacteria settle in and coexist. Still, diet explained only about a fifth of the differences between people, so it's one factor among many.

Variety isn't a bad thing, but the study suggests that steadiness and consistency — just like with exercise — matter more for your gut than you'd think. 

So if you've got a few genuinely good staples, keeping them in steady rotation is a feature, not a flaw.

Be Better
Why Your Workout Recovery Might Feel Slow

Your day-after soreness from a hard workout or a new training plan feels like something to fight. But it usually isn't, unless you have an injury and you can’t tolerate the pain. 

The mild inflammation after a hard workout is part of the signal that tells your muscles to repair and come back stronger. 

So when you reach for ibuprofen or another NSAID to numb routine soreness, you may be quieting the very process you trained to trigger.

Research suggests that higher doses of anti-inflammatory medications can blunt the strength and muscle gains you're working for.

You don’t need a pill to bounce back better. Instead, prioritize sleep, hit your protein target, move gently on rest days to keep blood flowing to sore muscles, and give yourself time to adjust and adapt to your workout. 

Save the anti-inflammatories for real injuries or when your doctor recommends them, not for everyday post-workout ache.

Soreness isn't the goal of a great workout, and it isn’t the enemy either. It's usually proof you showed up and did something new.

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

We do things a bit differently here, starting with transparency.

1. The Content: All APC emails are researched, written, and fact-checked by the APC editors (see bottom of the email), with written contributions from Arnold (noted with “Arnold’s Corner”). Links take you to original studies (not second-hand sources).

2. Does AI play a role? Not for the primary content, but it is used in two ways. The main items are original content written by the APC team. The summaries at the end are AI-generated based on the human-written content above. We also use an AI tool to review our interpretations of the research and ensure scientific accuracy. We don’t assume AI is right, but we use technology to hold ourselves accountable.

3. Yes, we have partners (all clearly noted by “Together With”). Why? Because it allows us to keep the APC emails free. We first test products, and then reach out to potential partners who offer ways to help you improve every day. The bar is set high, and to date, we have turned down millions in ad deals. (Example: we will not partner with any non-certified supplements or those without evidence in human trials). If we won’t buy the product, we won’t recommend it to you. And if there’s no evidence it works, then there’s no place for it here.

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Publisher: Arnold Schwarzenegger​

Editors-in-chief: Adam Bornstein and Daniel Ketchell