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A protein called PCSK9 helps break down the liver's 'LDL cholesterol cleaners,' so more bad cholesterol stays in your blood, raising heart disease risk. People with certain PCSK9 gene changes either...
Genes have a bigger influence on how much people sit at work than on how much they sit during free time.
Just because someone sits a lot doesn’t mean they’re genetically wired to be less active — sitting and moving aren’t exact opposites in our DNA, even though they’re somewhat linked in behavior.
How much you say you sit and how much you actually sit are somewhat linked — about 1 in 3 people who report sitting a lot really do. And nearly half of that link comes from shared genes, meaning your...
People's genes seem to play a smaller role in how they report their sitting time compared to their actual sitting habits — meaning how much you say you sit isn't as influenced by DNA as how much you...
More than half of why people sit or recline different amounts every day comes down to their genes, not just their habits or surroundings.
IGF-1 helps build muscle by turning on growth signals inside cells, and the IGF-1 made in the muscle itself might matter more than the kind that comes from the liver.
Lifting weights makes your body release more growth hormone, especially when you do medium-heavy sets with short breaks. This effect is weaker in older people.
When women work out during the part of their cycle when estrogen is high, they might build more muscle because estrogen helps protect muscles and speed up recovery.
In young men, how sensitive their muscles are to testosterone—measured by androgen receptor levels—matters more for muscle growth than how much testosterone is in their blood.
When men lift weights, their testosterone helps their muscles grow by turning on certain signals in the muscle cells. This hormone response can last up to two days after a workout, making muscles...
Young men need normal testosterone levels to get the full muscle-building benefits from weight training — low testosterone blunts the body’s muscle-growth signals.
Young men with low testosterone don't get the same muscle-building boost from weight training because their bodies don't increase the machinery needed to make new proteins — and that seems to be...
When young men have low testosterone on purpose for the study, their muscles don’t respond as well to weight training at the cellular level — testosterone seems to help muscles fully 'feel' and react...
Young guys need their natural testosterone to get the full muscle-building benefits from weightlifting — if their testosterone is blocked with drugs, their muscles don’t grow as much, even if they...
If young guys are given a drug that lowers their testosterone, they don’t build much muscle from weight training—while others with normal testosterone gain about 1.5 kg of muscle in 6 weeks. This...
Rats that swam regularly didn't get blood sugar problems from stress like the ones that didn't exercise — their bodies handled sugar just as well as unstressed rats.
Stressing out male lab rats for a long time makes their bodies worse at handling sugar, even though their resting blood sugar stays the same.
Swimming helps lower stress hormone levels in stressed-out male rats, which might mean exercise can calm an overactive stress system.
Stressing out male rats every day for 12 weeks made their stress hormone levels more than double, showing the stress method really works.
If male lab rats swim for an hour, five days a week for three months, they can swim much longer by the end — up to 2.7 times longer — which means their stamina and heart-lung fitness really improved.
Rats that slowly get used to running on wheels can run much longer than rats that don’t, showing that practice helps them handle exercise better.
Just being around a running wheel—even if they don’t run—helps male rats handle exercise stress a little better, but not as much as if they were used to using the wheel regularly.
Rats that got used to running on a wheel before a tough workout had lower sugar and stress markers in their blood compared to rats who weren’t used to it — meaning getting used to exercise might help...