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Exercises

Abs warm up: 6 minutes before crunches and sit-ups

Published October 24, 2026

Row easy for 2 minutes and do 30 seconds of jumping jacks, then 10 reverse crunches, 10 lying knee raises, 10 easy crunches and a 20-second plank, and finish with one light set of your first loaded ab exercise. About 6 minutes, and your abs have curled and braced before the hard sets.

  1. Rowing Machine Quads, Hamstrings, Glutes, Lats
  2. Jumping Jack Calves, Quads
  3. Reverse Crunch Abs
  4. Lying Knee Raise Abs
  5. Crunch Abs
  6. Plank Abs

Raise: 2 to 3 minutes

Your abs are already warm after any cardio; this just gets your heart rate up.

Raise: full-body easy cardio

Rowing Machine

Quads, Hamstrings, Glutes, Lats

Every stroke curls and straightens your trunk a little, so it is a good raise for ab day.

How to do it

  1. Strap your feet in and hold the handle with straight arms.
  2. Push with your legs first, then lean back slightly and bring the handle to your lower ribs.
  3. Reverse the order on the way back: arms forward, body tips forward, knees bend.
  4. Keep the pace conversational, around 20 strokes a minute.

Cues

  • Legs, body, arms; arms, body, legs
  • Easy enough to talk

Common mistakes

  • Racing the first minute: this is a warm-up, so finish feeling fresher than you started.

Swap for: Stationary Bike, Air Bike, Jump Rope

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Raise: quick cardio, no equipment

Jumping Jack

Calves, Quads

Thirty seconds tops off the raise when you finish the rower early.

How to do it

  1. Stand tall with feet together and arms at your sides.
  2. Hop your feet wide as your arms sweep overhead.
  3. Hop back to the start as the arms come down, staying light on the balls of your feet.

Cues

  • Quiet landings
  • Full arm sweep

Common mistakes

  • Landing flat-footed and heavy: stay springy and soft.

Swap for: High Knees, Jump Rope, Skipping in Place

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Curl the spine both ways: 2 minutes

Ab exercises curl the ribs toward the hips or the hips toward the ribs, so do light reps of both.

Activation: lower abs

Reverse Crunch

Abs

It curls from the bottom up, the half of ab work crunches miss.

How to do it

  1. Lie face up with knees bent at 90 degrees and hands by your sides.
  2. Curl your tailbone up, bringing your knees toward your chest.
  3. Lower your hips slowly back down.

Cues

  • Curl, don't swing
  • Slow down

Common mistakes

  • Throwing the legs with momentum: pause at the top of each rep.

Swap for: Lying Knee Raise, Dead Bug, Hanging Knee Raise

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Activation: hip flexors and lower abs

Lying Knee Raise

Abs

An easy set prepares the hip flexors and lower abs for hanging or decline work.

How to do it

  1. Lie flat with legs straight and hands at your sides.
  2. Bend your knees and draw them toward your chest.
  3. Straighten your legs back out just above the floor.

Cues

  • Back stays flat
  • Exhale as the knees come in

Common mistakes

  • The lower back arching as the legs straighten: stop the legs higher.

Swap for: Reverse Crunch, Dead Bug, Captain's Chair Knee Raise

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Activation: upper abs

Crunch

Abs

Ten easy crunches rehearse the curl you will load later.

How to do it

  1. Lie face up, knees bent, fingertips at your temples.
  2. Curl your shoulders off the floor by shortening the space between ribs and hips.
  3. Lower slowly.

Cues

  • Ribs to hips
  • Elbows wide

Common mistakes

  • Pulling on your head: hands only rest there.

Swap for: Toe Touch Crunch, Cable Crunch, Decline Crunch

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Activation: abs with the legs up

Toe Touch Crunch

Abs

A swap for crunches if your neck tires; reaching up shortens the motion.

How to do it

  1. Lie back with your legs straight up and a light ball or nothing in your hands.
  2. Reach your hands up toward your toes by lifting the shoulder blades.
  3. Lower your shoulders with control.

Cues

  • Reach up, not forward
  • Legs still

Common mistakes

  • Swinging the arms to get up: slow the reach.

Swap for: Crunch, Reverse Crunch, Cable Crunch

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Brace and twist: 1 minute

A short plank and a few twists so the rest of the trunk is ready too.

Activation: bracing

Plank

Abs

Lifting an arm and the opposite leg from a forearm plank switches on the brace without tiring it; twenty seconds per side is enough.

How to do it

  1. Rest on your forearms and toes with elbows under your shoulders and your body in one line.
  2. Reach one arm forward and lift the opposite leg, and hold without letting the hips tip.
  3. Lower both and switch to the other pair for the next hold.

Cues

  • Squeeze your glutes
  • Hips stay level as the limbs lift

Common mistakes

  • Hips twisting toward the lifted leg: lift lower and hold the line.

Swap for: Long Lever Plank, Dead Bug, Side Plank

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Activation: obliques

Russian Twist

Abs

A few slow twists warm the obliques before rotational work.

How to do it

  1. Sit with knees bent and lean back slightly with a straight back.
  2. Rotate your chest to one side, then the other.
  3. Keep your feet down if your back starts to round.

Cues

  • Turn the chest
  • Tall back

Common mistakes

  • Only moving the arms: the shoulders should turn.

Swap for: Cable Woodchop, Plate Standing Twist, Pallof Press

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First loaded ab exercise

Do one or two light sets of the first loaded exercise before the working sets.

Main lift: loaded ab flexion

Cable Crunch

Abs

The first loaded ab exercise for most gym ab days; one light set at half the stack is the ramp.

How to do it

  1. Stand facing away from a high pulley holding a rope beside your head.
  2. Curl your ribs down toward your hips, rounding your upper back.
  3. Return slowly to tall.

Cues

  • Round the spine
  • Hips stay still

Common mistakes

  • Hinging at the hips instead of curling: keep your hips over your feet.

Swap for: Machine Crunch, Decline Crunch, Crunch

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Main lift: harder ab flexion

Decline Crunch

Abs

Harder than a floor crunch, so do one easy set with your hands at your chest before adding weight.

How to do it

  1. Hook your feet on a decline bench and lie back.
  2. Curl up until your torso is upright.
  3. Lower slowly one vertebra at a time.

Cues

  • Curl up, roll down
  • Slow descent

Common mistakes

  • Dropping back fast: control every inch on the way down.

Swap for: Cable Crunch, Crunch, Machine Crunch

Build a session with Decline Crunch

Put them together: example sessions

Each session below picks from the exercises above for one situation, with the sets, reps, rest and RIR filled in. Open one in the session builder to change a pick, price it from a recent set, and add it to RIRLift.

Session 1

Gym ab session

Open in the session builder
  • Workouts2× a week
  • Working sets22 a week
  • Per workout~20 min
  • EquipmentRowing Machine, Adjustable Cable, Decline Bench

You do cable crunches and decline crunches.

Light curls in both directions and a short plank prepare the abs, and the cable crunch gets two ramp sets on the stack.

Gym abs
ExerciseSets × repsRIRRest
Rowing MachineSeconds. 2 minutes straight, no rest. 2 × 60 4 0 s
Reverse Crunch 1 × 10 4 15 s
Lying Knee Raise 1 × 10 4 15 s
PlankSeconds. 1 × 20 4 0 s
Cable Crunch2 warm-up sets first 3 × 10–15 1 1 min
Decline Crunch1 warm-up set first 3 × 10–15 1 1 min
How to run it
Do the warm-up, then the loaded ab work.
How to progress
Add one plate when you reach the top of the rep range at 1 to 2 reps in reserve.
Open in the session builder

Session 2

Floor ab circuit at home

Open in the session builder
  • Workouts3× a week
  • Working sets30 a week
  • Per workout~15 min
  • EquipmentDecline Bench

You do sit-ups and crunches on the floor.

No machines, so jacks raise the heart rate and the warm-up reps are the same moves at a much easier effort.

Home abs
ExerciseSets × repsRIRRest
Jumping JackSeconds. 1 × 60 4 0 s
Crunch 1 × 10 4 15 s
Reverse Crunch 1 × 10 4 15 s
Russian TwistPer side. 1 × 10 4 15 s
Toe Touch Crunch 3 × 12–20 1 45 s
Decline Crunch 3 × 10–20 1 45 s
How to run it
Do the warm-up, then your ab circuit.
How to progress
Add reps until each set hits 20, then slow the lowering.
Open in the session builder

Session 3

Abs at the end of a lifting session

Open in the session builder
  • Workouts2× a week
  • Working sets10 a week
  • Per workout~10 min
  • EquipmentAdjustable Cable

You finish a lifting day with abs.

You are already warm, so skip the raise and do one easy set of the move you are about to load.

Abs finisher
ExerciseSets × repsRIRRest
PlankSeconds. 1 × 20 4 0 s
Reverse Crunch 1 × 10 4 15 s
Cable Crunch1 warm-up set first 3 × 12–15 1 45 s
How to run it
Do the plank and reverse crunch, then cable crunches.
How to progress
Add load in small steps.
Open in the session builder

Make it fit you

Questions

How do you warm up for sit-ups?

Two minutes of cardio, then easy reverse crunches, crunches and a short plank before your first set.

What are good warm-up exercises for abs?

Reverse crunches, lying knee raises, easy crunches and a short plank after a couple of minutes of cardio.

Do abs need a warm-up?

A short one helps the first hard set feel smooth. Six minutes is enough.

Can I warm up abs with stretches?

Keep long holds for after. Before training, move through the curl at an easy effort.

Should I do abs first or last?

Last on lifting days, so they are fresh to brace for squats and deadlifts.