Ab Crunch Machine
An intermediate isolation movement that trains the abdominals with a machine.
Force Type
Pull
direction of effort
Difficulty
Intermediate
training level
Variations
0
equipment swaps
Muscles
1
primary + secondary
The verdict
Ab Crunch Machine has 4-step instructions, documented to a similar depth as most of the 93 abdominals exercises PlainExercise catalogues.
Ranked against the 93 abdominals exercises PlainExercise currently catalogues, not the full exercise-science literature.
Catalog lens
Two ways this record sits in the source corpus
These are placement measures for the documented record, not a score for exercise quality, safety, or suitability.
Instruction steps
#364 of 868
Typical documentation depth
Numbered source steps, ranked across every documented exercise.
Instruction text
#374 of 868
Typical documentation depth
A separate character-length placement prevents step count from standing in for explanatory detail.
Ab Crunch Machine vs every catalogued exercise by instruction-text length
Where this record's instruction-character count sits among all 873 Free Exercise DB exercises with instructions, not a rating of the movement itself.
661 374th of 873 higher than 499 of 873 exercises
All exercises, banded by instruction-text character count
Each bar is a band; taller bars hold more exercises. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source Free Exercise DB · 2026-07-10
Ab Crunch Machine is documented from the Free Exercise DB (CC0) extract, last ingested July 2026. Classification, muscle roles and instruction text are source facts; the placement and cohort measures on this page are computed by PlainExercise and are not a rating of the movement.
What the Ab Crunch Machine Data Reveals · DOC · PULL/ISOLATION
Ab Crunch Machine stands out on mechanic class: joint involvement separates this page from isolation peers.
A mid-length step list is enough detail to compare form without the longest upstream essays.
Across 93 catalogued abdominals movements, the average instruction record is 645 characters and 4.7 steps; 68 of those (73.1%) clear the same ≥500-character rich bar used here. This page ranks #45 of 93 by instruction-character length (1.02× the cohort average).
Among the 67 exercises that also use a machine, average instruction length is 786 characters; 37 of those peers are longer than this record. Equipment-matched peers are the honest comparison when you are choosing a substitute implement for the same pattern.
Other well-documented abdominals movements (same ≥500-character bar):
- Bosu Ball Cable Crunch With Side Bends (10 steps, 1,219 chars)
- Pallof Press With Rotation (9 steps, 1,113 chars)
- Exercise Ball Crunch (5 steps, 1,097 chars)
- Crunches (6 steps, 1,082 chars)
- Crunch - Legs On Exercise Ball (7 steps, 1,024 chars)
Context matters: taxonomy (level, mechanic, force, musculature, equipment) does not account for individual biomechanics, joint history, or recovery. Common-mistake framing below is derived from classification fields, not case-specific coaching. Not medical or personal-training advice. Consult a physician or certified trainer before starting, especially with injuries, cardiovascular conditions, recent surgery, or pregnancy.
Ab Crunch Machine catalog footprint
Among 93 exercises whose primary muscle is abdominals, Ab Crunch Machine ranks #12 by catalogued variation count. The upstream file attaches 2 images to this slug. See the step-count ranking for abdominals for peer documentation depth.
Muscles worked
The Free Exercise DB classifies each muscle as primary or secondary. It does not measure activation, so we show involvement, not percentages.
Source: Free Exercise DB primary/secondary muscle classification. Actual recruitment varies by load and form.
Intensity context
For reference, here is where common activities sit on the MET intensity scale. Ab Crunch Machine does not have a measured MET in the source data, its intensity depends on the load and effort you use. Estimate calories for any activity with the calorie calculator.
MET values from the Compendium of Physical Activities (Ainsworth et al., 2011). A general reference scale, not a rating of this specific movement.
How to do it
- Select a light resistance and sit down on the ab machine placing your feet under the pads provided and grabbing the top handles. Your arms should be bent at a 90 degree angle as you rest the triceps on the pads provided. This will be your starting position.
- At the same time, begin to lift the legs up as you crunch your upper torso. Breathe out as you perform this movement. Tip: Be sure to use a slow and controlled motion. Concentrate on using your abs to move the weight while relaxing your legs and feet.
- After a second pause, slowly return to the starting position as you breathe in.
- Repeat the movement for the prescribed amount of repetitions.
Common mistakes
- Rushing through reps, controlled tempo (2-3s down, 1-2s up) is what drives muscle tension on Ab Crunch Machine, not raw speed.
- Cutting the range of motion short - moving the abdominals through its full safe range on Ab Crunch Machine is what most reliably separates effective reps from wasted ones.
- Using momentum instead of muscle, isolation movements like Ab Crunch Machine reward strict form. If you're swinging the weight, it's too heavy.
- Shrugging the shoulders up toward the ears on pull movements, keep shoulder blades down and back to load the correct muscles.
- Breathing out of sync with the lift on Ab Crunch Machine - brace and inhale during the lowering phase, exhale on the exertion, especially important with a machine where control matters most.
Who this is for
- People with 6+ months of consistent training who can perform basic compound lifts with good form
- People who want to train the Abdominals
- People who have access to a machine
Who this is NOT for
- People hunting equipment swaps, this record has none to offer; browse the peer abdominals exercises for alternate patterns instead.
- Anyone with acute pain in the joints or muscles involved, pain is a stop signal, not a soreness signal
- People with unresolved injuries in the loaded joints, seek clearance from a physical therapist first
- Anyone with a recent surgery, cardiovascular limitation, or pregnancy complication without physician clearance
Progression path
Once Ab Crunch Machine feels comfortable with your current load, progress by (a) adding reps until you can complete 12+ per set, (b) increasing resistance by 2.5-5%, (c) moving to harder variations such as single-limb or longer lever versions, and eventually (d) stepping up to expert-level movements that train the same muscle.
See the Progression guide for a full framework on when to advance, and the Compound vs Isolation guide to decide when to prioritize this movement in your program.
Safety notes · MACHINE · PULL/ISOLATION · MID
- Intermediate PULL/ISOLATION: warm up mobility matching abdominals before Ab Crunch Machine with a machine.
- Sharp or joint pain is a stop signal. Muscle soreness during sets is normal; pain is not.
- Adjust sets, reps, and rest to recovery; 4 upstream steps are a template, not a prescription.
- General information only. Consult a physician or certified trainer before starting any new exercise program.
Curated workout appearances
Ab Crunch Machine appears in 12 of the 186 curated workout routines on this site.
Nationwide exercises with similar documentation depth
Two Free Exercise DB peer sets for Ab Crunch Machine, drawn across all muscles (not the abdominals-only related list below). Each metric produces a different neighborhood.
Similar instruction step count
Nearest catalog records by numbered steps.
Similar instruction text length
Nearest catalog records by upstream instruction characters.
Related exercises
Other exercises that target the Abdominals.
See all Abdominals exercises.
Using the ab crunch machine
Three ways to put it to work.
- Train the abdominals 2–3 times a week with 48+ hours between hard sets; pair this with other abdominals movements for balanced development. All abdominals exercises
- Match the load and rep range to your goal, strength, size, or endurance each call for a different scheme. Strength vs hypertrophy
- As an isolation movement, use it to target the abdominals directly after your compound lifts. Compound vs isolation
Form before load. If a movement causes sharp or joint pain, stop and substitute a safer alternative, this is general information, not medical or training advice.