I often get asked, "Which one is better?" The answer is.....BOTH!
BOTH are excellent! BOTH engage the core. BOTH are extremely effective. You should work on BOTH!
**The forearm plank demands more tricep, and fights a greater demand from gravity.
**The high plank allows a bit of tricep relief, but puts more demand on the shoulders to stabilize.
**The high plank is actually performed at an easier angle, and uses more large muscles, thus distributing the effort. The closer you come to upright(standing), the easier the it becomes.
Beginners, start at the wall. Place your forearms parallel to one another on the wall. Step your feet back to a position where you can engage your mid-section (core), and place yourself in an angled, plank position. Pull your stomach in, and squeeze your glutes. Hold for 30 seconds, and repeat two more times. The muscle engagement will develop your strength very quickly. As you gain strength, walk your feet further away from the wall; eventually getting yourself to the floor. From there, start on your knees, keeping your hips down and tight. Never compromise your posture, don't hold your breath, and relax your mind. Message me for tips on intermediate and advanced plank workouts, and any questions.