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Today’s Health Upgrade
Fact or fiction: coffee and cancer
How carbs help fight diabetes
The truth about slow reps and muscle growth
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Fact or Fiction
Does Too Much Coffee Or Tea Cause Cancer?
Coffee and tea are two of the most popular beverages in the world. But is the common daily habit slowly causing more harm than you want?
A new study analyzed more than 2 million people and found no association between coffee and tea consumption and gliomas, a deadly type of brain cancer.
The researchers analyzed data from 9 cohort studies—think of it as gathering a giant jigsaw puzzle from various long-term research projects. They compared the highest versus lowest consumption groups of coffee and tea to see if there was a measurable difference in glioma risk.
If you love coffee, you can feel good that you’re not harming your body. And if you’re a tea drinker, the news was even more positive.
The data analysis suggests that people who drink more than 2.5 cups of tea per day have a lower risk of brain cancer.
This follows another recent study that found tea and coffee consumption was also linked to a lower risk of head and neck cancer. However, for those cancers, drinking several cups per day appeared to increase protection.
Compared with non-coffee drinkers, individuals who drank more than four cups of caffeinated coffee daily were 17 percent less likely to have head and neck cancer overall, 30 percent less likely to have oral cancer, 22 percent less likely to have throat cancer, and 41 percent less likely to have throat cancer.
The studies hint that bioactive compounds and antioxidants in these beverages may contribute to positive health outcomes, though the exact mechanisms remain a subject of ongoing research.
Nutrition
The Whole Grain That Can Help You Beat Diabetes
You might have heard that carbs can cause diabetes. But the reality is that the right carbs could help improve your blood sugar and keep you healthier.
New research suggests that quinoa can improve glucose tolerance and reduce the risk of type 2 diabetes.
The randomized controlled trial compared the effects of quinoa consumption with other whole grains in individuals with impaired glucose tolerance (IGT)—a condition that significantly increases the risk of developing type 2 diabetes.
Participants were split into two groups: One group ate a diet rich in quinoa-based meals, while the other group consumed a variety of other whole grains, such as brown rice, oats, and whole wheat.
After several weeks, the quinoa group experienced lower fasting blood sugar, better insulin sensitivity, and significant overall improvements in glucose metabolism. In fact, more participants in the quinoa group reverted to normal glucose tolerance, which means they were no longer considered pre-diabetic.
Quinoa is rich in protein and fiber, which slow digestion and prevent rapid blood sugar spikes. It also has magnesium, an essential mineral that helps regulate glucose metabolism.
If you don’t like quinoa, don’t worry. The real lesson is that the combination of protein and fiber can go a long way towards keeping you healthy. If you want to try quinoa a few times per week, you can use it as a base for salads, in place of rice, or even in breakfast porridge.
Fitness
The Truth About Slow Reps and Muscle Growth
Some people believe that slowing down their reps will help build more muscle. The idea makes sense on the surface—more time under tension should mean more growth. But that’s not how it works.
Research suggests that intentionally slow, controlled reps don’t lead to more muscle growth because they don’t create the mechanical tension needed to maximize hypertrophy.
Instead, the unintentionally slow reps—when your muscles struggle to move the weight—are the ones that matter most.
Researchers have found that mechanical tension is the primary driver of muscle growth. When you lift heavier weights or push lighter weights to failure, your muscles experience higher levels of mechanical strain. This forces your body to recruit more motor units, especially the high-threshold ones responsible for muscle growth.
So, you can grow with high reps and lower weight or with lower reps and higher weight. But this is where people get confused and think they should just slow down the pace of their reps.
It’s good to think about muscle growth as a game where you win by applying more force. If you use a lighter weight and move that weight slowly on purpose — to increase time under tension — you are applying less force than you could. That means the stimulus your muscles need to grow is less than ideal.
The problem is that those slow reps are making your muscles burn. So it feels like it’s working, but it’s deceiving.
A different study found that intentionally slowing down reps increases the perception of fatigue but doesn’t necessarily increase mechanical tension or motor unit recruitment. In other words, it makes the set feel harder, but that doesn’t mean it’s more effective.
When your muscles are working so hard and have achieved enough fatigue that they cannot move the weight quickly, that’s the type of “slow reps” that are effective.
These “hard reps” are where mechanical tension peaks, rep speed unintentionally slows down, and you’re maximizing muscle growth.
As a rule of thumb, you want the last 1 to 3 reps of any set to be the “hard reps,” where you still can control the weight, but you’ve found the right balance between intensity and fatigue to maximize force and tension.
It’s why the most popular article in The Pump app is “first set mindset.” It’s the idea that you approach each and every set like it’s your first and only set, so you can learn how to push yourself as needed.
To make the most of every session, remember:
Don’t force slow reps—focus on controlled but explosive movements during the concentric phase (lifting the weight).
Push sets close to failure to ensure you reach those reps where your movement slows down naturally.
Use loads heavy enough (65-85% of your 1-rep max) to challenge your muscles and force high-threshold motor unit recruitment. There are exceptions to the rules and times when you might need to use lighter weights (such as with injury). And remember, strength is relative to your ability. What is light for one person can be heavy for another, and as long as it’s challenging to you, that’s all that matters.
If you’re slowing reps down on purpose, you might just be making your workout feel harder without making it more effective.
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Publisher: Arnold Schwarzenegger
Editors-in-chief: Adam Bornstein and Daniel Ketchell
