Welcome to the positive corner of the internet. Every weekday, we make sense of the confusing world of wellness by analyzing the headlines, simplifying the latest research, and offering quick tips designed to make you healthier in less than 5 minutes. If you were forwarded this message, you can get the free daily email here.
Today’s Health Upgrade
Number you won’t forget
Do late workouts wreck your sleep?
“The confidence effect”
Weekly wisdom
Natural recovery boost (you’re probably not using)
Arnold’s Podcast
Want more stories from Arnold? Every day, Arnold’s Pump Club Podcast opens with a story, perspective, and wisdom from Arnold that you won’t find in the newsletter. And, you’ll hear a recap of the day’s items. You can subscribe on Apple, Spotify, Google, or wherever you listen to podcasts.
Nutrition
Number You Won’t Forget: 411
We often hear that cold exposure can boost metabolism. However, new research reveals that chilling out could be counterproductive to weight loss goals.
A new controlled trial found that while chilly temperatures may make you eat more, they might not help you burn more.
Researchers had participants complete four separate 24-hour stays in a metabolic chamber — a sealed environment where all calories burned and consumed can be precisely measured. Each person spent time in a neutral temperature and a colder—but—not—freezing environment, while eating as much as they wanted. Importantly, they also completed a day where calorie intake was tightly controlled to match expenditure for each temperature, so researchers could accurately compare the metabolic effects of cold.
In the colder environment, participants ate significantly more—an average of 411 extra calories per day—than in the warmer setting.
However, despite the increased food intake, there were no meaningful differences in 24-hour energy expenditure, respiratory exchange ratio (RER), or carbohydrate oxidation during cold exposure.
Interestingly, the study found that people exposed to cooler temperatures were likelier to eat more the next day.
To be clear, this study did not test freezing temperatures, so it’s possible that colder conditions could have a bigger impact on metabolism. Cold can also condition mental toughness, help with recovery, or trigger dopamine.
However, this new study and others suggest it’s not a weight-loss hack because the cold increases hunger.
Health
Are Your Late Workouts Wrecking Your Sleep?
We always hear that exercise improves sleep, but it turns out that when you exercise, it might matter just as much as whether you exercise.
New research found that exercising too close to bedtime—especially at a high intensity—can delay sleep onset, shorten sleep duration, lower sleep quality, and mess with nighttime recovery.
Researchers analyzed over 4 million nights of biometric sleep data from 14,689 active individuals who wore biometric devices for an entire year. They wanted to understand how exercise timing and intensity (what they called “exercise strain”) affected objective sleep metrics.
High-strain exercise up to 6 hours before bedtime delayed sleep onset, and harder workouts 2 hours before bed led to people falling asleep 36 minutes later compared to lighter exercise.
If you’re trying to prioritize recovery, the scientists found that exercising within 4 hours before bed was linked to less sleep overall, increased resting nighttime heart rate, and decreased heart rate variability (HRV), all of which are signs of reduced recovery.
The researchers believe intense exercise elevates adrenaline, core body temperature, and sympathetic nervous system activity. These changes make it harder for the body to shift into “rest and digest” mode, which is essential for deep, restorative sleep.
Of course, if your only time to work out is later in the day, choosing some exercise over no exercise is better. The study did not find that you can’t get quality sleep when you exercise at night; compared to exercising earlier in the day, later workouts tend to reduce overall sleep quality.
Together With Tecovas
“The Confidence Effect”
Science has a name for what happens when the clothes you wear change how you feel: Enclothed cognition.
Researchers found that what you wear doesn’t just affect how others see you—it shapes how you think, feel, and perform. Confidence, focus, and posture are all influenced by what’s on your body.
Arnold didn’t know the science then, but he lived it.
When he first moved to America, he had a vision for who he wanted to become, and part of bringing that vision to life included a specific look: polo shirts, jeans, and cowboy boots.
The boots weren’t just style. They were a symbol. Of strength. Of belonging. Of becoming the version of himself he saw in his mind.
Decades later, he still wears them. And so do we.
That’s why we love Tecovas, the handcrafted boot brand that embodies everything we believe in at Arnold’s Pump Club: confidence, craftsmanship, and standing tall in who you are.
Tecovas boots look amazing and feel broken in on day one. They’re built to last—and made for people who lead from the front.
Our favorites? The Dean. The Cartwright. And for a lower heel, The Earl.
If you’re ready for a small shift that makes a big difference, this might be the simplest confidence upgrade you’ll ever try. Step into something better.
Weekly Wisdom
On Our Radar
A Natural Recovery Boost You’re Probably Not Using
Most people turn to ice, massage, or foam rolling for sore muscles. But there may be a simple supplement that speeds recovery—and it comes from apples and onions.
Recent research suggests that quercetin can help you bounce back and recover faster from your hardest workouts.
Researchers analyzed data from 13 studies involving everyone from beginners to advanced trainees. Quercetin supplementation was associated with reduced muscle soreness, less muscle damage, quicker strength restoration, and less fatigue in follow-up workouts.
The researchers believe quercetin’s anti-inflammatory and antioxidant properties play a key role. It reduces oxidative stress and inflammation triggered by strenuous activity, allowing the body to recover faster and more efficiently. In all but one study, quercetin supplementation was 1,000 mg per day.
As we frequently remind you, supplements should supplement foundational behaviors like nutrition and sleep. Make those a priority. If you want to add another layer to your recovery, the existing evidence suggests quercetin is a low-risk recovery enhancer.
And that’s it for this week. Thank you for being a part of the positive corner of the internet, and we hope you all have a fantastic weekend!
-Arnold, Adam, and Daniel
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Publisher: Arnold Schwarzenegger
Editors-in-chief: Adam Bornstein and Daniel Ketchell
