The short answer
Hollow hold or Plank?
Choose the hollow hold if you are training for calisthenics skills. It is the shape the front lever and a straight handstand are built on, and Aion's L-sit ladder starts with it. Choose the plank if you want a sturdier trunk for lifting and daily life: it is easier to learn and easy to make harder. Since each one trains the trunk against arching, one of them is enough as your main hold. Build the hollow from a tuck until 40 clean seconds with straight legs and arms overhead come easily.
Side by side
| Question | Hollow hold | Plank |
|---|---|---|
| What it is | Lie on your back, press the lower back into the floor, and lift the shoulders and legs so the body makes a shallow, rigid curve. | Face down on your forearms and toes, hold a straight line from head to heels. |
| Equipment | A floor | Nothing |
| Position | Face up, lower back pressed into the floor, shoulders and legs lifted | Face down, a straight line from head to heels on forearms and toes |
| Pelvis | Tucked under by design; the hold is over when it lets go | Neutral in the standard version; tucking it is a harder variation |
| Lever | You set it: knees in or legs out, arms by the hips or overhead | Fixed by your height unless you move the elbows forward or drop the knees |
| Carries over to | Front lever, L-sit, the straight handstand line, hollow rocks, toes-to-bar | Push-ups, burpees, holding still under a barbell or a heavy carry |
| How it fails | The lower back peels off the floor; you feel it before anyone sees it | The hips sag or pike; a phone filming side-on shows it |
| Wrists, neck, shoulders | Nothing on the wrists; the neck holds the head up, and arms overhead need shoulder mobility | Forearms spare the wrists; the shoulders carry the front of you |
| Target | 3 sets of 20 to 40 seconds on Aion's L-sit ladder, exit at 40 clean | Hold until the line changes; college students averaged 83 to 124 seconds to failure |
Choose the hollow hold when
- You want a front lever, an L-sit, a handstand or clean toes-to-bar.
- You hold a minute-long plank comfortably and want a harder position, not a longer hold.
- Planks bother your wrists or elbows and you still want a hard trunk hold.
Choose the plank when
- Your goal is general strength, lifting, or a back that lasts the working day.
- Even the tuck hollow lifts your lower back off the floor. A forearm plank, or a dead bug before that, teaches the brace with less to get wrong.
- Your neck gives out before your abs do in the hollow.
- You are building toward push-ups, which are a plank that moves.
Using both in one week
Give one hold the main work and let the other live in the warm-up. A skills athlete makes the hollow the main core work two or three days a week, 3 sets of 20 to 40 seconds, and warms up with a plank or two. On days with front lever or L-sit practice, the skill comes first and the hollow after it, because a tired trunk practises a worse shape. A lifter flips it, and the plank and its harder versions carry the work.
Tuck hollow to full hollow, then into the skills
- Tuck hollow: knees pulled toward the chest, shoulders off the floor, hands on the shins, lower back flat. 3 sets of 20 to 40 seconds.
- Knees bent at a right angle with the feet off the floor, arms by the hips reaching toward the feet. Same sets; move on at 40 clean seconds.
- One leg straight, then both, high enough that the back stays down. Lower them a few centimetres at a time over the weeks.
- Full hollow: arms overhead beside the ears, legs straight and low. Aion moves you on at 40 clean seconds.
- Hollow rocks: the same shape rocking from shoulder blades to hips, sets of 10 to 20. If the shape breaks, hold still instead.
- Into the skills: the support hold and the tuck L-sit on the L-sit ladder, or the tuck front lever once active hangs and scapular pull-ups are in place.
The numbers
- Forearm plank to failure
- Men 124 s, women 83 sAverages for 194 men and 277 women at college, each with a spread of over a minute (Strand 2014). Past that, a harder shape teaches more than a longer clock.
- Plank with a longer lever and a tucked pelvis
- Higher at all 3 abdominal sitesUpper abs, lower abs and obliques against a standard plank, 19 adults, 30 second holds; the longer lever added more than the tuck (Schoenfeld 2014). Those are the two traits that define a hollow.
- Most lower-ab activity of 8 planks
- Suspended roll-out plank20 university students on EMG; the side planks drew most on the lower back muscles (Calatayud 2017). The plank's harder versions change the setup, not the time.
- Plank with the feet raised
- More from all 3 abdominal sites24 young adults with their feet on wall bars at five heights; every raised version beat the flat plank for the upper abs and both obliques (Moreno-Navarro 2024). A step under the feet is the cheapest harder plank there is.
Mistakes that cost the most
- Arching the lower back to get the legs lower. A low leg with a gap under your back is a different exercise; raise the legs until the back stays down.
- A held breath. Take short breaths behind the brace; if you cannot, the shape is too hard for today.
- Counting seconds after the shape broke. Only clean seconds count, so a 25 second hollow beats a 60 second sag.
- Treating a long plank as front lever training. The lever is held face up under a bar with the pelvis tucked; a face-down hold with a neutral pelvis is a different shape.
Questions people ask
Is the hollow hold better than the plank?
For calisthenics, yes: the hollow trains the tucked pelvis and long lever that levers and handstands use, and the standard plank does not. For general trunk strength, no: a plank and its harder versions are easier to learn and to load, and that covers what most lifters need.
Plank or hollow hold: which should I do first?
Whichever you can hold cleanly. If a tuck hollow keeps your back flat for 20 seconds, start there and drop the plank as a main exercise. If even the tuck lifts your back, spend two or three weeks on dead bugs, which teach the same flat back with one leg out at a time.
Hollow hold vs dead bug: what is the difference?
The dead bug moves one arm and the opposite leg while the back stays down; the hollow holds both arms and both legs off the floor, still. The dead bug is the easier move and the better teacher. When 10 slow reps a side keep your back on the floor, try the tuck hollow.
Sources
- An electromyographic comparison of a modified version of the plank with a long lever and posterior tilt versus the traditional plank exerciseSports Biomechanics, 2014
- Norms for an isometric muscle endurance testJournal of Human Kinetics, 2014
- Progression of Core Stability Exercises Based on the Extent of Muscle ActivityAmerican Journal of Physical Medicine and Rehabilitation, 2017
- Trunk muscle activation in prone plank exercises with different body tiltsJournal of Back and Musculoskeletal Rehabilitation, 2024
Figures on this page come from the studies above or from the arithmetic shown. Read how claims are reviewed and updated in How the guides are written.