Browse evidence-based analysis of health-related claims and assertions
When you push hard with your knee bent all the way back, your thigh muscles have to work much harder internally than when your knee is only slightly bent—even if you’re pushing with the same force on the machine.
Causal
Even though your muscles feel just as sore and your blood shows similar signs of damage after doing leg exercises with your knee bent far back or only slightly bent, your muscles are actually weaker and harder to activate for longer after the deep bend version.
Doing strength exercises with your knee bent further back makes your muscles weaker and harder to activate for up to two days afterward—even when you’re testing them at different knee angles—compared to doing the same exercise with your knee less bent.
One way the liver breaks down alcohol doesn’t mess up the cell’s energy balance like other ways do — so it might be a safer way to clear alcohol, even if it’s not the main one.
Mechanistic
A natural switch in the liver (PPARα) that turns on fat-burning also turns up a cleanup enzyme (catalase) that helps remove alcohol — but this can accidentally make liver damage worse by creating too much hydrogen peroxide.
When the liver breaks down fat in tiny compartments called peroxisomes, it makes hydrogen peroxide — and that same chemical can help break down alcohol faster, especially if you eat a lot of fat.
When the liver uses a specific enzyme (CYP2E1) to break down alcohol, it accidentally creates harmful free radicals that damage liver cells, especially with long-term drinking.
When the liver breaks down alcohol, it creates a chemical imbalance that stops the liver from burning fat, causing fat to build up in the liver.
When too many fat molecules and inflammatory signals from belly fat reach the liver, it becomes less responsive to insulin.
Descriptive
Where fat is stored in the body — especially around the organs — is linked to how the liver processes energy and how sensitive it is to insulin.
Fat around the organs sends out chemicals that talk to liver cells and immune cells inside the liver.
Fat around the organs sends out fat molecules and inflammatory signals directly into the liver through a major blood vessel.
Too much fat around the organs is linked to higher blood sugar, higher bad fats in the blood, and lower good cholesterol, which can lead to diabetes and heart problems.
Muscles that stretch across two joints (like the hamstrings) don’t grow as well when one joint is bent — you need to position both joints right to fully stretch them and make them grow.
Correlational
Doing a full squat or starting a bicep curl from the bottom makes your muscles grow more at the far ends (like the top of your thigh or the outer part of your bicep) than doing partial reps from the top.
Just stretching your muscle under light weight won’t make it grow — you need to push hard while it’s stretched out, like doing a bicep curl slowly at the bottom where it’s fully extended.
Even if you lift heavier weights with your muscles mostly bent, you don’t grow bigger muscles than if you lift lighter weights with your muscles stretched out — the stretch matters more than how heavy the weight is.
Lifting weights when your muscles are stretched out more (like at the bottom of a squat or a full bicep curl) tends to make them grow bigger than lifting with your muscles mostly shortened, as long as there's still resistance pushing back when they're stretched.
If you eat enough protein (like 25g per meal), your muscles will grow even if you eat almost no carbs—carbs aren’t needed for building muscle.
Insulin doesn’t make your muscles grow bigger after lifting weights—it just helps stop your muscles from breaking down, especially if you’ve eaten enough protein.
Rats that ate almost no carbs but lots of fat and protein still grew just as much muscle as rats eating a normal high-carb diet when both did weightlifting.
Even if your muscles are low on stored sugar (glycogen), your body still builds muscle just as well after lifting weights, as long as you eat enough protein.
Even eating very little carbs—like just 30 grams a day—doesn’t make you weaker during weightlifting workouts, which means you might not need to eat a lot of carbs to lift heavy.
Exercise makes muscles better at using insulin and the liver produce less sugar—but those improvements don’t match up with changes in chemerin levels, meaning chemerin isn’t the main reason exercise helps insulin work better.