Browse evidence-based analysis of health-related claims and assertions
After losing weight, the body slows down calorie burning to save energy — but eating more protein stops this slowdown, so the body burns calories at the expected rate again.
Causal
When people who lost weight eat more protein and fewer carbs, their bodies burn more calories at rest and end up in a calorie deficit, which might help them keep the weight off.
Even though people can do more work with 5-minute breaks, they don’t feel like they’re working harder or have a higher heart rate than with 2-minute breaks.
Descriptive
Resting 5 minutes between hard leg pushes leads to less burning and fatigue in the muscles than resting only 2 minutes.
Quantitative
When resting 5 minutes between hard leg pushes, your muscles stay more 'turned on' than when you only rest 2 minutes.
After doing hard leg pushes, people who rest 5 minutes between sets lose much less strength than those who only rest 2 minutes.
When doing intense leg exercises with 5-minute breaks between sets, people can do more total work than with only 2-minute breaks, which might help muscles grow stronger over time.
Lifting weights with one joint (like leg extensions) transfers better to holding a static position than complex lifts like squats, because it’s easier for your body to use the same muscle pattern in both cases.
Beginners get much stronger from weight training than experienced lifters do, because the body’s ability to adapt slows down after you’ve been training for a while.
Some people grow more muscle with regular heavy lifting, others grow just as much or more with heavy lifting plus blood flow restriction — there’s no one-size-fits-all answer.
Being strong at lifting weights doesn’t mean you’re strong at pushing or holding something still—even with the same muscles—because your body uses different systems for moving vs. holding.
When you do heavy lifting while restricting blood flow, your muscles work harder and get more 'burned out' during the workout than when you lift heavy without restricting blood flow.
Even though lifting weights makes your muscles bigger and more active, those changes don’t explain why you get stronger—meaning something else, like how your nerves coordinate movement, might be more important.
Mechanistic
You can’t just count how many reps you do to know if your workout is good enough — how long your muscles are under strain matters just as much, maybe more.
When people who’ve never lifted weights before train their chest and arms with the same total muscle tension time, the back part of their triceps (near the elbow) grows more than the middle or shoulder-end parts.
When two different ways of lifting weights are adjusted so that the total time your muscles are under strain is the same, both ways lead to about the same strength gains and muscle growth in people who haven’t trained before.
The link between muscle mass or calorie burn and how much you eat gets weaker the older you get.
Correlational
How much fat a person has doesn’t seem to affect how much they eat, but how much muscle they have or how many calories they burn does.
Older adults who burn more calories each day tend to eat more, but this link gets weaker as they get older.
Older people with more muscle tend to eat more, but this link gets weaker as they get older.
When people eat more protein, their blood shows higher levels of a waste product called urea, which means their body is breaking down more protein than when they eat more carbs.
When people eat more protein and fewer carbs, their bodies hold onto more protein instead of breaking it down and losing it, which means they’re building or maintaining muscle better.
Eating a diet high in protein and low in fat makes your body burn about twice as much energy after meals compared to eating a diet high in carbs and low in fat.
Even if your hormones spike a lot right after your first few workouts, that doesn’t mean you’ll grow more muscle or get stronger later on.