Jefferson Curl

Muscles worked by the Jefferson Curl

Primary

Lower BackErector SpinaeHamstringsHamstring Muscles

Secondary

GlutesGluteus Maximus

Also called: erector spinae, spinal erectors, lower back muscles, back extensors, hamstring, hamstrings.

Equipment

Dumbbell

Also called: db, dumbell, hex dumbbell, rubber dumbbell, hand weight.

How to do the Jefferson Curl

1. Stand tall holding a light dumbbell with straight arms, feet roughly hip-width.
2. Tuck your chin and begin rounding the spine from the top, one vertebra at a time.
3. Curl down slowly, letting the weight hang and keeping the legs mostly straight.
4. Reach the bottom with the back fully rounded and a stretch through the hamstrings.
5. Reverse it, restacking the spine from the bottom up back to standing.

Form tips

• Use a very light weight -- this is a controlled mobility drill, not a heavy lift.
• Round segment by segment; do not hinge at the hips like a stiff-leg deadlift.
• Move slowly and never bounce at the bottom.

At a glance

Jefferson Curl in German & Spanish

Descriptions, instructions and tips ship in all three languages in the JSON.

Related exercises

• Back Extension
• Barbell Deadlift
• Bench Child's Pose
• Bodyweight Good Morning
• Bow Pose
• Cat Stretch
• Cat-Cow
• Child's Pose

Exercise data (JSON)

The record below is exactly what exercises.json ships for this exercise — names, descriptions, instructions and tips in English, German and Spanish.

{
  "id": "jefferson-curl",
  "name_en": "Jefferson Curl",
  "name_de": "Jefferson Curl",
  "name_es": "Jefferson curl",
  "description_en": "A loaded spinal-flexion drill: standing tall with a light weight, you round the spine one vertebra at a time and restack it, building segmental control and hamstring/spinal-erector flexibility under load.",
  "description_de": "Eine belastete Wirbelsäulenbeugung: Im aufrechten Stand rollst du die Wirbelsäule mit leichtem Gewicht Wirbel für Wirbel ab und wieder auf und schulst so segmentale Kontrolle sowie die Beweglichkeit von Beinbeuger und Rückenstrecker unter Last.",
  "description_es": "Un ejercicio de flexión espinal con carga: de pie y con un peso ligero, redondeas la columna vértebra a vértebra y la vuelves a apilar, desarrollando control segmentario y flexibilidad de isquiotibiales y erectores bajo carga.",
  "category": "strength",
  "force_type": "pull",
  "mechanic": "compound",
  "difficulty": "intermediate",
  "equipment": "dumbbell",
  "body_part": "back",
  "primary_muscles": [
    "erector_spinae",
    "hamstrings"
  ],
  "secondary_muscles": [
    "gluteus_maximus"
  ],
  "goals": [
    "hypertrophy",
    "strength"
  ],
  "is_unilateral": false,
  "is_bodyweight": false,
  "instructions_en": [
    "Stand tall holding a light dumbbell with straight arms, feet roughly hip-width.",
    "Tuck your chin and begin rounding the spine from the top, one vertebra at a time.",
    "Curl down slowly, letting the weight hang and keeping the legs mostly straight.",
    "Reach the bottom with the back fully rounded and a stretch through the hamstrings.",
    "Reverse it, restacking the spine from the bottom up back to standing."
  ],
  "instructions_de": [
    "Stehe aufrecht und halte eine leichte Kurzhantel mit gestreckten Armen, Füße etwa hüftbreit.",
    "Ziehe das Kinn zur Brust und beginne, die Wirbelsäule von oben Wirbel für Wirbel abzurollen.",
    "Rolle langsam nach unten, lass das Gewicht hängen und halte die Beine weitgehend gestreckt.",
    "Erreiche unten die volle Rundung des Rückens mit einer Dehnung in den Beinbeugern.",
    "Kehre die Bewegung um und stapele die Wirbelsäule von unten nach oben zurück in den Stand."
  ],
  "instructions_es": [
    "Ponte de pie sujetando una mancuerna ligera con los brazos estirados, pies aproximadamente al ancho de las caderas.",
    "Mete la barbilla y empieza a redondear la columna desde arriba, vértebra a vértebra.",
    "Baja despacio dejando colgar el peso y manteniendo las piernas casi rectas.",
    "Llega abajo con la espalda totalmente redondeada y un estiramiento en los isquiotibiales.",
    "Invierte el movimiento, reapilando la columna de abajo hacia arriba hasta ponerte de pie."
  ],
  "tips_en": [
    "Use a very light weight -- this is a controlled mobility drill, not a heavy lift.",
    "Round segment by segment; do not hinge at the hips like a stiff-leg deadlift.",
    "Move slowly and never bounce at the bottom."
  ],
  "tips_de": [
    "Nimm ein sehr leichtes Gewicht — das ist eine kontrollierte Mobilitätsübung, kein schwerer Lift.",
    "Rolle Segment für Segment ab; klappe nicht wie beim gestreckten Kreuzheben aus der Hüfte.",
    "Bewege dich langsam und federe unten niemals."
  ],
  "tips_es": [
    "Usa un peso muy ligero: es un ejercicio de movilidad controlado, no un levantamiento pesado.",
    "Redondea segmento a segmento; no bisagres desde la cadera como en un peso muerto rígido.",
    "Muévete despacio y nunca rebotes abajo."
  ],
  "met": 6.0,
  "images": {
    "flat": {
      "start": "images/flat/jefferson-curl-start.webp",
      "peak": "images/flat/jefferson-curl-peak.webp"
    }
  }
}

Fetch just this exercise

const { exercises } = await fetch(
  "https://exercise-dataset.com/exercises.json"
).then(r => r.json());
const ex = exercises.find(e => e.id === "jefferson-curl");

Free for personal and commercial in-app use with attribution (“Exercise data by RepDB”) — see the license and ready-made attribution snippets. Redistributing the data as a dataset or API is not permitted.