- EquipmentDumbbell
- PatternIsolation
- Reps5 to 10 reps
- Joint loadLower back
Stand on a sturdy box or step holding a very light dumbbell in front of your thighs, legs straight.
First cueMove very slowly.
How to do the Jefferson Curl
Set up. Stand on a sturdy box or step holding a very light dumbbell in front of your thighs, legs straight.
- Tuck your chin and roll your spine down one section at a time.
- Let the dumbbell lower toward your feet.
- Roll back up slowly, stacking the spine from the bottom.
Form cues
- Move very slowly.
- Keep the legs straight.
- Start with no weight at all.
Common mistakes
- Using a heavy weight.
- Moving quickly.
Take care. Start with no weight or a very light one and add load only slowly; skip it if rounding the back under load causes discomfort.
Muscles worked
Main target: Lower back. The erector spinae run either side of the spine. They straighten the back and hold it straight under a load, in every hinge, squat and carry.
On the way: Hamstrings.
Its other side: Abs, in the trunk pattern.
What to pair it with
Movements that round out a workout with the Jefferson Curl, from the same catalog the StatBlockFit app logs.
- Hanging Leg Raise Superset partner: it trains the other side of the trunk pattern, so the two can alternate.
- Cable Woodchop Same core session: it trains the obliques.
A complete workout around it
4 movements, the Jefferson Curl first, at the catalog's rep ranges. Load it into the workout builder to change the sets, reps and weights, then bookmark it or download it.
- Jefferson Curl 3 × 5 to 10 reps
- Hanging Leg Raise 3 × 6 to 20 reps
- Cable Woodchop 3 × 10 to 20 reps
- Cable Crunch 3 × 10 to 20 reps
Alternatives and swaps
The same main muscle with other equipment: a swap never changes the muscle a workout trains.
Home or dumbbell swap
Back Extension
Bodyweight
Gym or cable swap
Reverse Hyperextension
Machine
A swap describes the movement, not your body: if a joint hurts, ask a professional before you train it.
Working weight and 1RM calculator
Enter a set you did: the weight, the reps and how many more reps you had left in you. The estimate is the formula the StatBlockFit app uses for its records, weight × (1 + (reps + reps in reserve) ÷ 30); above 12 reps it is rough.
Training zones
| Zone | Share of 1RM | Usual reps |
|---|---|---|
| Strength | 85 to 90 % | 3 to 6 |
| Muscle growth | 70 to 80 % | 6 to 12 |
| Endurance | 60 to 65 % | 15 to 20 |
A warm-up before the working sets: 50 % for 5, 70 % for 3 and 85 % for 1, each rounded down to a plate.
Common starting points, not a prescription: the right weight is the one you can lift with good form for the reps you planned.
Variations and preparation
Do before it: Cat-Cow (bracing) and Seated Hamstring Stretch (hip range).
Track it in StatBlockFit
In the StatBlockFit app the Jefferson Curl is logged set by set: the app suggests your next weight after each session, times your rests, keeps your records and shows the 72-hour recovery of every muscle on its training map. The training guide explains how.
Questions
How do you do the Jefferson Curl?
Set up: Stand on a sturdy box or step holding a very light dumbbell in front of your thighs, legs straight. Steps: 1. Tuck your chin and roll your spine down one section at a time. 2. Let the dumbbell lower toward your feet. 3. Roll back up slowly, stacking the spine from the bottom. Form cues: Move very slowly. Keep the legs straight. Start with no weight at all. Common mistakes: Using a heavy weight. Moving quickly. Take care: Start with no weight or a very light one and add load only slowly; skip it if rounding the back under load causes discomfort.
What muscles does the Jefferson Curl work?
It trains the lower back as its main target and works the hamstrings on the way.
What can I do instead of the Jefferson Curl?
At home: Back Extension. In a gym: Reverse Hyperextension. Each trains the same main muscle.
What should I pair the Jefferson Curl with?
Good partners in the same workout are Hanging Leg Raise and Cable Woodchop.
How heavy should the Jefferson Curl be?
Pick a weight you can lift for the planned reps with one or two left in reserve. As a common starting point, sets of 3 to 6 reps use about 85 to 90 percent of your one-rep max and sets of 6 to 12 reps about 70 to 80 percent; the calculator on this page does the arithmetic.