David Kirsch may train celebrities like Jennifer Lopez, Britney Spears, and Heidi Klum, but thanks to the power of the Internet, we like to think he's our trainer, too. Kirsch regularly posts his ...

You have to engage your core constantly as you sit straight, stand tall, and walk confidently, which requires a lot of endurance in your midsection muscles. The best way to build ab endurance? A core ...

When you buy through links on our articles, Future and its syndication partners may earn a commission. Credit: Getty Images If you have 10 minutes to spare and a couple of dumbbells to hand, then this ...

"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links." No offense to sit-ups, planks, and hollow holds, but basic core exercises can feel drab day after day.

Better posture. Weak upper abs often result in poor posture and spinal misalignment, but by targeting these muscles, you can ...

Tighten your core after 50 with 5 walking sequences: incline, arm-drive, intervals, posture walking, and high-knee bursts.

As a runner, you don’t want to neglect core strength. These key midsection muscles provide the stabilization and upright posture you need to run efficiently and injury-free. And you can really turn up ...

"Sometimes pressing play and just starting is the hardest part," says fitness instructor Tanner Courtad in this total-body workout video. "But what you'll always find out is that you build momentum, ...

This quick, four-move dumbbell workout targets your upper body and core. It's perfect for a mid-holiday energy boost.

While crunches, sit-ups, planks, and other floor-bound movements are effective core-strengthening exercises, standing abdominal workouts offer unique benefits, especially for runners. If you’re ...

Kick off your fitness journey this New Year with quick, effective exercises designed specifically for women embracing their ...