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Exercise library · Abs

Backpack crunch

Trunk flexion for the abs with other equipment.

How to do it

1 of 3

Backpack tight to your chest

  1. Starting position

    Lie on your back with bent knees and feet on the floor, holding the backpack firmly against your chest with both hands.

  2. The movement

    Curl your torso and lift your shoulders toward your hips, then lower your back slowly to the floor.

Most common mistake

Don't sit all the way up, lift only your shoulders and keep your lower back close to the floor.

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Muscle group
Abs
Equipment
Other
Where
Home or gym
Logged as
Reps

Muscles worked

The backpack crunch is a crunch with a packed backpack as the weight. The rectus abdominis is the prime mover as your spine curls forward, with help from the obliques. The backpack does not change which muscles work, but it makes every rep heavier, so your abs tire in far fewer reps. That makes it a good way to load your abs at home, where there are seldom dumbbells or a cable machine.

Common mistakes

  • The contents shift around. Loose items moving inside the bag make the weight unstable. Pack it tightly, put the heaviest things closest to the back panel and pull the straps in.
  • You pack it too heavy too soon. An overloaded bag drags your technique down and makes you jerk yourself up. Start with a few books or water bottles and add a little at a time.
  • The backpack slides up towards your chin. That pushes your head forward and makes your neck work. Keep the bag on your lower chest with your arms crossed over it.

Variations and alternatives

  • Crunches without weight are the right starting point if you cannot yet manage 15 controlled reps.
  • The cable crunch is the gym's way to load the same movement, with exact weight steps.
  • The toe touch crunch keeps the short crunch movement with your legs towards the ceiling, for a change without packing the bag.

Sets and reps

With the backpack you can train your abs like any other muscle: two to four sets of 10 to 15 reps, with a weight that makes the last reps really hard. One way to find the right load is to end each set with one or two reps left, known as reps in reserve. The guide to sets and reps gives the background to the rep ranges.

Weigh the backpack so you know what you are lifting: step on a scale with and without it and work out the difference. Then add one book or bottle at a time once you manage 15 reps in every set. A litre of water weighs about a kilo, so the steps stay small. That is progressive overload with what you have at home.

Also called

  • weighted crunch

Swap for

Taken, or missing the equipment? The same movement with something else.

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