Crunch Fitness exec and Marine Corps. vet Jim Rowley stays fit and healthy at 58 with Pilates, dumbbell workouts, and a precise supplement stack.

The tech giant says the new personal health coach is a fitness trainer, sleep coach, and wellness advisor all in one.

Crunches, teasers, planks, and body-weight squats are some of the best stomach exercises for stronger abs. A strong core improves balance and posture.

Are morning workouts better for weight loss? What's the best time for working out: morning, afternoon or evening? Experts say it depends on your goals, but that any movement — no matter the time ...

Here's what the exercise is, which muscles it works and why crunches are so good for overall health.