To end a high-energy set, Williams suggests a short circuit of jumping jacks, squats, inchworms, and mountain climbers. She ...

Plank Jack to Alternating Mountain Climber. Start in high plank position. Perform one plank jack by jumping both feet apart and back together—like a jumping jack on the floor (as shown).

To do a mountain climber, start in a plank position, with your hands shoulder-width apart, your back flat, and your core engaged (think about sucking your belly button into your spine).

When it comes to core exercises, the plank is the where it's at. Try these plank variations to modify the exercise or increase the challenge, or simply to spice up your next workout.

Mountain Climbers. DjordjeDjurdjevic/E+/Getty Images. To get your heart pumping in a plank, try mountain climbers — aka a cardio-based variation of the core exercise. Start in high plank.

Similar to mountain climbers, the plank jacks raised my heart rate as I jumped my legs in and out. They are also much lower impact than say burpees or high knees, so this is definitely a move I ...

Mountain climbers are total body workouts, building strength in your core, back, arms and legs — not to mention your heart. ... Set 2: Plank, Bodyweight Split Squat and Single-Leg Hip Raise.

I did plank holds every day for 30 days and felt my core and arms get stronger. ... DAYS 13-15: Plank variations (mountain climbers, push-ups, and side planks)— 20 seconds on, ...