In this week’s Health newsletter: A group of overlooked muscles are key to aging well, an 86-year-old who just completed her 1,000th skydive has advice on staying young, and scientists are figuring out how to make cancer cells self-destruct. 

But first: The science of why your body resists weight loss.

Research shows the battle to keep weight off isn’t about willpower—it’s biology. Here’s how scientists say we can work with our bodies, not against them.

Kim Knor has the kind of biography Hollywood blockbusters are made of—and has just notched a new milestone in her quest to keep living life to the fullest.

Today’s newsletter was edited and curated by William O'Connor and produced by Amanda Williams-Bryant. Did someone forward this to you? Sign up here to get this newsletter and more.