Upper vs Lower Abs: The Best Exercises for Each

When training the abdominal muscles, it’s essential to understand that while the rectus abdominis functions as a single muscle, specific exercises can target the upper or lower sections more effectively.

This article provides a scientific analysis of how to train both areas optimally, focusing on the best exercises for each.

Anatomy of the Abdominal Muscles

The rectus abdominis, colloquially known as the “six-pack,” runs vertically from the ribcage to the pelvis. It is divided into the upper and lower sections by connective tissue bands known as tendinous inscriptions.

While these sections work in unison during most movements, their activation levels can differ depending on the type of exercise.

Studies using electromyography (EMG) confirm that certain exercises increase muscle activity in either the upper or lower portion of the rectus abdominis (Contreras et al., 2011).

How to Train the Upper Abs

Understanding Upper Ab Activation

Upper ab activation is generally more prominent during movements where the torso curls forward, bringing the ribcage closer to the pelvis. This includes crunching, curling, or flexing the upper spine. Research indicates that exercises emphasising spinal flexion with the ribcage as the primary mover result in greater upper abdominal engagement (Escamilla et al., 2006).

Best Exercises for the Upper Abs

1. Crunches

Crunches are a foundational upper ab exercise. By curling the shoulders off the ground while keeping the lower back stationary, the movement isolates the upper portion of the rectus abdominis effectively.

How to Perform:

Lie on your back with your knees bent and feet flat on the floor.
Place your hands lightly behind your head without pulling.
Curl your upper back off the floor, contracting your abs.
Lower back down slowly and repeat.

2. Decline Bench Sit-Ups

Adding an incline increases the challenge for the upper abs by extending the range of motion.

How to Perform:

Set a decline bench at a moderate angle.
Lie back with your feet secured under the pads.
Sit up until your upper torso is perpendicular to the bench.
Lower yourself slowly to maintain tension in the upper abs.

3. Cable Rope Crunches

Cable crunches introduce resistance, making them excellent for building upper ab strength and size.

How to Perform:

Kneel in front of a cable machine with a rope attachment at the top.
Hold the rope, positioning it near your ears.
Curl your torso downward, bringing your elbows toward your thighs.
Return slowly to the starting position.

How to Train the Lower Abs

athlete does lower abs workout on pull-up bar

Understanding Lower Ab Activation

The lower abs are activated more intensely during movements that involve lifting the pelvis or legs toward the torso. EMG data shows that exercises incorporating hip flexion place more emphasis on the lower portion of the rectus abdominis (Axler & McGill, 1997).

Best Exercises for the Lower Abs

1. Hanging Leg Raises

Hanging leg raises effectively target the lower abs by requiring controlled pelvic tilts.

How to Perform:

Hang from a pull-up bar with your legs straight.
Lift your legs until they are parallel to the ground, focusing on tilting the pelvis upward.
Lower your legs slowly to the starting position.

2. Reverse Crunches

Reverse crunches minimise lower back strain while isolating the lower abs.

How to Perform:

Lie flat on a mat with your legs bent at 90 degrees.
Lift your hips off the floor by curling your pelvis toward your ribcage.
Lower your hips back to the mat under control.

3. Mountain Climbers

This dynamic movement engages the lower abs and improves overall core stability.

How to Perform:

Assume a high plank position with your hands under your shoulders.
Drive one knee toward your chest, then quickly switch legs in a running motion.
Maintain a controlled pace for optimal lower ab activation.

Incorporating Both Upper and Lower Abs in a Routine

For balanced abdominal development, your training routine should target both the upper and lower abs. A well-rounded workout might include one to two exercises for each area, performed two to three times per week. Rest periods between sets should range from 30 to 60 seconds to maintain intensity.

Example Routine:

Crunches: 3 sets of 15 reps
Hanging Leg Raises: 3 sets of 12 reps
Decline Bench Sit-Ups: 3 sets of 12-15 reps
Reverse Crunches: 3 sets of 12-15 reps

Common Mistakes to Avoid

Over-relying on Hip Flexors: Ensure lower ab exercises engage the abdominal muscles rather than the hip flexors by tilting the pelvis upward during movements.
Neglecting Breathing: Exhale during the contraction phase of each exercise to maximise core engagement.
Poor Posture: Avoid excessive arching of the lower back during both upper and lower ab exercises to prevent strain.

The Role of Nutrition in Abdominal Definition

Ab exercises alone will not reveal a defined six-pack. A caloric deficit achieved through proper nutrition is essential for reducing body fat. Protein-rich foods and a balanced macronutrient profile support muscle retention while promoting fat loss (Phillips & Van Loon, 2011).

Bibliography

Axler, C. T., & McGill, S. M. (1997). “Low back loads over a variety of abdominal exercises: Searching for the safest abdominal challenge.” Medicine and Science in Sports and Exercise, 29(6), 804-810. doi:10.1097/00005768-199706000-00014.
Contreras, B., Vigotsky, A. D., Schoenfeld, B. J., & Beardsley, C. (2011). “Electromyographic analysis of upper and lower rectus abdominis during abdominal exercises.” Strength and Conditioning Journal, 33(5), 84-92. doi:10.1519/SSC.0b013e31822a541d.
Escamilla, R. F., Babb, E., DeWitt, R., & Scruggs, K. (2006). “A three-dimensional biomechanical analysis of spine loading during execution of the power clean.” Journal of Strength and Conditioning Research, 20(1), 95-102. doi:10.1519/R-16574.1.
Phillips, S. M., & Van Loon, L. J. C. (2011). “Dietary protein for athletes: From requirements to optimum adaptation.” Journal of Sports Sciences, 29(S1), S29-S38. doi:10.1080/02640414.2011.619204.