Plank
Muscles worked : Core (abdominals, lower back) · Shoulders
How to do it
- Place your forearms on the floor, elbows under the shoulders, and extend your legs behind you.
- Line the body up straight from heels to head.
- Squeeze the glutes and draw the navel in slightly to lock the core.
- Hold the position breathing normally, eyes towards the floor.
Common mistakes
- Hips riding up into a peak: reduces the work on the abdominals.
- Hips sagging: loads the lower back — that is the signal to end the set.
- Holding your breath instead of breathing normally.
Where you should feel it
Tension spread across the whole abdominal wall and the glutes. If the load shifts to the lower back or the shoulders, the position has degraded: holding on has no value any more, better to end the set.
Range of motion
No range — it is the quality of the alignment that counts. A straight line from heels to head, neither hips peaked nor sagging, eyes down so the neck stays in line with the back.
Tempo and breathing
A continuous hold, breathing normally and audibly. The stopping criterion is not the clock but the position: as soon as the hips go, the set is over, even with ten seconds left.
What works, precisely
The transverse abdominis and rectus abdominis hold ribcage and pelvis aligned, the obliques prevent rotation. The glutes slightly extend the hip to remove the arch, and the serratus anterior keeps the shoulder blades flat. The erector spinae work in co-contraction with the abdominals.
Movement mechanics
An isometric anti-extension exercise: gravity pulls the pelvis towards the floor and the abdominal wall stops it. No joint moves, which makes the position highly dependent on alignment — a few degrees of pelvic tilt completely changes which muscle carries the load.
Benefits
- Builds core endurance, the quality that protects the back when standing for a long time or carrying a load.
- Involves no repeated spinal flexion, unlike conventional abdominal work.
- The hold teaches you to breathe under tension, a reflex that pays off in every other exercise.
Adapt and progress
- Easier : Put the knees down, or place the forearms on a raised surface.
- Harder : Extend the duration, or briefly lift one foot then the other while keeping the hips still.
- Move on when : When three forty-five-second holds go by with no loss of position, extend or add complexity.
Precautions
Do not hold your breath. If the lower back pulls, the position has already sagged: come down and restart rather than gritting it out.