WhatWorksWhat.
Lower back

Jefferson Curl

Hamstring stretch all the way through, plus a long-overlooked stretch through the entire spinal column.

Complexity · Mediummobilityintermediate+Dumbbells
  • Hamstrings
  • Lower back
  • Lower back - Spinal erectors
  • Spinal erectors

PrimarySecondary

What it hits

Parts of the target muscle.

  • Spinal erectors

    Hit

    Erector spinae - keeps the spine neutral under load.

The movement

Get it right, not roughly right.

Optimal form

7:51· That Fit Friend

JEFFERSON CURL GUIDE | How To, Benefits, and Mistakes!

Hinge bottom

Lockout

Stand on a low box with a LIGHT dumbbell or kettlebell. Roll forward through the spine vertebra by vertebra, letting the back fully round as the weight lowers between the legs. Reverse the curl back up.

Common mistakes

  • Going heavy - this is a mobility exercise, not a strength one.
  • Bending only at the hips - the whole point is the segmental spinal flexion.

Where you should feel it

Hamstring stretch all the way through, plus a long-overlooked stretch through the entire spinal column.

Injury risk · 5/10

SafetyLoaded spinal flexion is the most-debated movement in strength training. Start unloaded, add weight in 5-lb jumps, and stop if anything sharper than a stretch shows up.

Variations

Same movement, moved emphasis.

Ranked by how directly each variation still trains lower back. 80%+ means the target barely changes. Below 60%, the emphasis has meaningfully shifted — useful for variety, but less precise for the specific part. The label calls it at a glance.

  • PVC Jefferson curl

    Unloaded.

    95% on target

    On target

    Same target, minor adjustment.

  • Banded Jefferson curl

    Band loop in the hands.

    90% on target

    On target

    Same target, minor adjustment.

Compare with another exercise

Cool-down

Worked it. Walk it back down.

A couple of minutes here pays back in soreness avoided tomorrow. Browse the full library.

  • Child's Pose

    Knees wide, big toes together. Sit hips back to the heels, arms long overhead, forehead to the floor. 60s. Walk the hands one direction to bias one side.

    LatsLower backRhomboids

  • Happy Baby

    Lying on the back. Grab the outsides of the feet, knees pulled toward the armpits. Gently rock side to side. 60s. The cheapest lower-back decompression you can do.

    GlutesLower backHamstrings

  • Seated Forward Fold

    Seated, legs straight in front. Hinge from the hips and reach the hands toward the feet. Don't force the back to round - go where it goes. 60s.

    HamstringsLower backCalves

Coach note

Controversial. Some coaches love it for building a resilient spine, others hate it. Start unloaded, build slowly, never max it.