Exercise guide
Diagonal Reach On Chair
- Intermediate
- Compound
- Rep-based
- Shoulders
- Upper arms
- Waist
This seated core exercise targets the obliques and rectus abdominis through controlled rotation and hip flexion, making it an excellent low-impact option for improving spinal mobility and core stability.
Reviewed by the Crucible team · Updated June 2026
Muscles worked
Setup
- Sit upright on the front edge of a stable chair with your feet flat on the floor, hip-width apart.
- Engage your core and maintain a tall, neutral spine with your chest lifted.
- Extend your arms out to your sides at shoulder height or place your hands lightly behind your ears.
How to do it
- Exhale as you rotate your torso and reach one hand diagonally across your body toward the opposite knee.
- Simultaneously lift that opposite knee toward your chest to meet your hand, focusing on the crunch in your side-abs.
- Inhale as you slowly return to the starting upright position with a controlled tempo.
- Repeat the movement on the opposite side, alternating sides for each repetition.
Form checklist
- Keep your spine long and avoid rounding your lower back as you reach.
- Initiate the rotation from your midsection rather than just moving your arms.
- Keep your planted foot firmly on the ground to maintain balance.
- Ensure your hips stay glued to the chair throughout the entire movement.
Pro tips
- Think about bringing your ribcage toward your opposite hip to maximize the contraction of the internal and external obliques.
- Pause for one second at the peak of the reach to emphasize the mind-muscle connection with your core.
Make it harder
- Straighten your leg as you lift it to increase the lever length and resistance on the lower abs.
- Hold a light weight or water bottle in your hands to add resistance to the rotational phase.
Frequently asked
- What muscles does the diagonal reach on chair work?
- The diagonal reach on chair primarily targets the abs and obliques, and also works the serratus anterior and trapezius as secondary muscles.
- What equipment do you need for the diagonal reach on chair?
- The diagonal reach on chair requires no equipment — just your body weight.
- Is the diagonal reach on chair good for beginners?
- The diagonal reach on chair is rated intermediate. Build a base with simpler variations first, then progress to it with light load and strict form.