Health Claims

For people who don't usually work out, using a knee extension machine grows the front thigh muscle much more than using a leg press machine.

You don’t need to dunk your whole body in cold water after a workout—just cooling the sore muscles works just as well for recovery.

Taking a cold-water plunge after exercise might make your jumping power worse right afterward, especially if only part of your body is in the water — but soaking your whole body doesn’t seem to have...

Taking cold baths or cold plunges after exercise might make you *feel* better, but it doesn’t actually help your muscles get stronger faster in the first 72 hours.

Taking a cold-water bath after exercise probably helps reduce muscle soreness, especially in the first day, and the effect seems real even when accounting for biased studies.

Taking cold baths or cold showers after working out might slightly lower a marker of muscle damage in healthy people, but the benefit could be smaller than studies suggest because of biased reporting.

In people who don't work out much, the amount of muscle in their arms and legs is closely linked to the strength of their bones in those same limbs — more muscle usually means stronger bones.

Wider shoulders usually mean more muscle in the arms — in people who don't train much, this link is pretty strong.

If you're new to lifting weights, things like how much you eat, how much protein you get, how old you are, or your BMI don’t really help predict how much muscle you’ll gain in the first few months.

If you're new to lifting weights, having more muscle at the start doesn't really mean you'll gain more muscle from training — it's not a strong predictor of results, especially once you account for...

If you're new to strength training, your bone size or density doesn't really predict how much muscle you'll gain in the first few months—people with all kinds of frames tend to gain muscle at similar...

Eating more nuts may help older women live longer — especially by lowering their chances of dying from heart disease or stroke over the next 15 years.

If you're 49 or older, eating a moderate amount of nuts—more than very little but not the most—might help you live longer by lowering your chances of dying from heart disease.

If you're 49 or older and eat more nuts—especially compared to people who eat very few—you might live longer. One study found that people who ate a moderate amount had about a 24% lower chance of...

Eating more nuts might help you live longer — studies show people who eat the most nuts have about a 23% lower chance of dying from heart disease or any cause compared to those who eat the least.

Eating a small handful of nuts every week might help lower your chances of getting heart disease by a little bit.

If you eat more nuts, you might have a lower chance of getting heart disease — people who eat the most nuts seem to have about 1 in 5 fewer cases of heart problems than those who hardly eat any.

If you're an adult and eat nuts at least seven times a week, you might be less likely to die from any cause over time — about 20% less likely, according to this claim.

Getting more sleep might help athletes think faster, move better, and improve their game skills — but scientists haven’t studied this as much as things like power naps.

Taking naps can help athletes feel less tired and more alert, and might boost both their physical and mental performance—making it a handy way to make up for lost sleep at night.

Not getting enough sleep can hurt athletic performance, especially for sports that need quick thinking or precise moves—like tennis or basketball—more than for sports that are mostly about strength...

When athletes train harder, their deep sleep increases, which helps their body recover and adapt by boosting growth hormone and handling stress from workouts.

When athletes do the same hard workouts over and over without variation, they’re more likely to get sick, hurt, or burn out.

A special two-part fitness test might tell the difference between overreaching and full overtraining by how the body’s stress hormones respond the second time around.