Side Jackknife

A beginner strength exercise for the abs, done with just your bodyweight.

Main muscles: Abs
Equipment: Bodyweight
Level: Beginner
Type: Compound
Movement: Pull

How to do the Side Jackknife

Sets and reps

Strength	3–5 sets of 3–5 reps, rest 2–3 minutes
Muscle	3–4 sets of 6–10 reps, rest about 2 minutes
Endurance or fat loss	2–3 sets of 12–15 reps, rest 60–90 seconds

Log every set in MyoStats and it works out your estimated one-rep max and suggests the next weight or rep target, so you keep progressing without guessing.

Alternatives to the Side Jackknife

Questions

What muscles does the Side Jackknife work?

Mainly the abs.

Is the Side Jackknife good for beginners?

Yes. It's rated a beginner exercise: start light and learn the movement before adding weight.

What can I do instead of the Side Jackknife?

Good alternatives that train the abs: 3/4 Sit-Up, Air Bike, Bent-Knee Hip Raise or Bottoms Up.

How many sets and reps of the Side Jackknife should I do?

Strength: 3–5 sets of 3–5 reps, rest 2–3 minutes. Muscle: 3–4 sets of 6–10 reps, rest about 2 minutes. Endurance or fat loss: 2–3 sets of 12–15 reps, rest 60–90 seconds.

Exercise steps and photos: free-exercise-db (public domain).