Skill level: Beginner
Type: Bodyweight
Equipment: No Equipment
Body parts: Abs, Obliques

The bicycle crunch is a dynamic exercise that strengthens the core, lower abdominals, and lower back. The movement also improves stability, balance and coordination.

Skill level: Beginner
Type: Strength Training
Equipment: No Equipment
Body parts: Abs, Obliques, Back

The sit-up is a basic bodyweight exercise that strengthens the entire core region, more specifically the lower abdominals. The exercise also improves lower back strength.

Skill level: Beginner
Type: Strength Training
Equipment: No Equipment
Body parts: Delts, Pecs, Triceps

In order to prevent shoulder injury, correct form requires you to keep the crooks of your elbows pointing forward and preventing your elbows from flaring out to the sides.