Best Core Exercises

FAQ

Why does my lower back hurt during core exercises like sit-ups and leg raises?

The most common culprit is hip flexor dominance. When the hip flexors (primarily the iliopsoas) are doing the bulk of the work, they pull hard on the lumbar vertebrae. During a sit-up, if your lower back arches off the floor before your shoulder blades lift, that's the signal. Leg raises are a particular flashpoint: as the legs descend toward the floor, the lumbar spine tends to hyperextend unless the pelvis is actively posteriorly tilted and the transverse abdominis is pre-tensioned. Shortening the lever (bending the knees), placing hands under the sacrum, or switching to a dead bug variation where the lower back stays pressed into the floor can dramatically reduce the compressive load while still challenging the abs effectively.

Is there a meaningful difference between training the upper and lower abs?

Anatomically, the rectus abdominis is one continuous sheet of muscle, so you can't fully isolate an upper or lower portion. That said, EMG research does show some regional emphasis depending on the movement. Exercises where the ribcage moves toward the pelvis (crunches, cable crunches) tend to show higher activation in the upper fibers, while exercises where the pelvis tilts toward the ribcage (reverse crunches, hanging knee raises) show relatively greater involvement of the lower fibers. For practical programming, mixing both types of movement gives you more complete stimulation across the full muscle belly, rather than locking into one pattern exclusively.

How often should the core be trained compared to other muscle groups?

The core recovers faster than most large muscle groups, partly because it's engaged as a stabilizer during almost every compound movement you do. Many lifters find they can handle direct core work three or four times per week without issue, especially if the exercises are lower-load stabilization patterns. More intense loaded movements like heavy cable crunches or loaded carries may warrant more recovery time between sessions. A useful framing from coaches like Dan John is that carries and anti-rotation work can slot into nearly any session as 'filler' without taxing recovery budgets the way a heavy deadlift day does.

Do I need to train core differently if my main goal is aesthetics versus athletic performance?

The goal shapes the exercise selection more than the frequency or volume. For aesthetics, visible abdominal definition is primarily a body composition question, meaning fat loss creates the visual, but exercises that maximally shorten and lengthen the rectus abdominis under load (cable crunches, weighted sit-ups) tend to contribute to muscle thickness that shows through once body fat is low enough. For athletic performance, the priority shifts toward anti-rotation and isometric strength, things like Pallof presses, Copenhagen planks, and loaded carries, because sports rarely demand repeated trunk flexion and almost always demand resisting unwanted movement while force is transferred through the hips and legs. Most programs benefit from elements of both, weighted flexion for hypertrophy and stability work for function.