The case for training and feeding your muscles holds up well for building strength, but the idea that extra nutrition alone protects muscle is where the research gets shaky.

The core message holds up well. Other research on older adults found that stopping weight training for a few months caused them to lose some of the muscle they'd gained, and that resistance training programs helped older women and adults with early muscle loss build strength and lean mass. The claim that physical decline creeps up slowly also has support — long-running studies that tracked walking speed, balance, and grip strength found these abilities do tend to fade over years, sometimes gradually before accelerating near the end of life. Where things get messier is nutrition. One study found protein supplements alongside exercise helped older people keep more muscle and strength, but another found that in people who weren't eating enough protein, supplements didn't beat exercise alone — and a third found protein only helped when paired with heavy lifting, not on its own. The evidence that training and nutrition together prevent everyday capability loss is also thinner than the post implies: one study showed resistance training improved daily physical tasks, but adding protein didn't help further, and muscle mass didn't even increase. So exercise looks like the stronger lever here, and the nutrition story is more mixed than the post lets on.