Weighted Sit-Up

The loaded core classic — builds ab strength and endurance through full spinal flexion with progressive resistance

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⚡ Quick Reference

Aspect	Details
Pattern	Core (Spinal Flexion)
Primary Muscles	Abs (entire rectus abdominis)
Secondary Muscles	Hip Flexors, Obliques
Equipment	Weight plate, dumbbell, or medicine ball
Difficulty	⭐⭐ Intermediate
Priority	🟡 Supplementary

Movement Summary

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🎯 Setup

Starting Position

1. Weight selection: Start light (5-10 lbs) — you can always add more
2. Lie down: On your back on floor or mat
3. Weight placement: Hold weight at chest with both hands or arms extended
4. Knees: Bent at 90 degrees, feet flat on floor
5. Feet: Anchor under something or have partner hold (optional but helpful)
6. Head/neck: Relaxed, neutral spine

Weight Placement Options

Position	Difficulty	When to Use
At chest	Standard	Most common, balanced
Overhead	Harder	More challenge, longer lever
Behind head	Moderate	Alternative grip

Setup Cue

"Weight at chest, knees bent, feet secured — ready to curl up from the floor"

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🔄 Execution

The Movement

🔝 Starting Position

What's happening: Lying flat, weight held, ready to curl

1. Lying on your back
2. Weight held at chest (or overhead if advanced)
3. Knees bent, feet flat or anchored
4. Core engaged, ready to initiate

Feel: Weight pressing against chest, core braced

⬆️ Sit Up

What's happening: Curling spine to sit all the way up

1. Start by lifting shoulders and upper back off floor
2. Curl spine progressively — think "rolling up" vertebra by vertebra
3. Continue until you're sitting upright
4. Keep weight close to body throughout
5. Exhale as you come up

Tempo: 1-2 seconds

Feel: Abs contracting from bottom to top, hip flexors engaging as you near vertical

⏸️ Top Position

What's happening: Sitting upright with full spinal flexion

1. Torso vertical or slightly past vertical
2. Abs fully contracted
3. Weight still at chest
4. Brief pause at top

Common error here: Rushing through top — pause for a moment to maximize contraction.

⬇️ Lower

What's happening: Controlled descent back to floor

1. Slowly lower yourself back down
2. "Unroll" spine vertebra by vertebra
3. Keep weight close to chest
4. Control the descent — don't just drop
5. Inhale as you lower

Tempo: 2-3 seconds

Feel: Eccentric loading through abs, resisting gravity

Key Cues

Primary Cues

• "Roll up, vertebra by vertebra" — sequential spinal flexion
• "Weight stays at chest" — don't let it drift forward
• "Control the descent" — slow eccentric phase
• "Exhale up, inhale down" — proper breathing pattern

Tempo Guide

Goal	Tempo	Example
Strength	2-1-3-0	2s up, 1s pause, 3s down
Hypertrophy	2-2-3-0	2s up, 2s pause, 3s down
Endurance	1-0-2-0	Continuous movement

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💪 Muscles Worked

Activation Overview

Primary Movers

Muscle	Action	Activation
Rectus Abdominis	Spinal flexion — curling torso up	████████░░ 80%

Secondary Muscles

Muscle	Action	Activation
Hip Flexors	Hip flexion — pulling torso toward thighs	███████░░░ 70%
Obliques	Stabilization, assists flexion	██████░░░░ 55%

Stabilizers

Muscle	Role
Neck Flexors	Keep head aligned with torso
Arms/Grip	Hold weight in position

Training Note

Sit-ups have higher hip flexor activation than crunches because of the full ROM. This is neither good nor bad — just different. If you want isolated abs, stick to crunches or reverse crunches.

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⚠️ Common Mistakes

Mistake	What Happens	Why It's Bad	Fix
Too much weight	Form breaks down	Back strain, momentum takes over	Start light, progress slowly
Jerky movement	Using momentum	Less muscle activation	Smooth, controlled tempo
Pulling on neck	Hands behind head pulling	Neck strain	Keep hands at chest or crossed
Straight back	Not curling spine	Less ab engagement	"Roll up" vertebra by vertebra
No foot anchor	Feet lifting off floor	Can't complete movement	Anchor feet or have partner hold

Most Common Error

Using too much weight too soon — this causes you to jerk and use momentum instead of controlled ab contraction. Start lighter than you think.

Self-Check Checklist

• Weight appropriate (can do 10+ controlled reps)
• Smooth curling motion, not jerky
• Controlled eccentric phase
• No neck pulling or strain
• Feet stay on ground (or properly anchored)

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🔀 Variations

By Difficulty

Easier (Regressions)

Variation	How	When to Use
Bodyweight Sit-Up	No weight	Learning the movement
Crunch	Partial ROM	Isolating abs only
Dead Bug	Alternating legs	Building control

Standard

Variation	How	Emphasis
Weight at Chest	Standard hold	Most common
Weight Overhead	Arms extended	Longer lever, harder

Harder (Progressions)

Variation	How	When to Use
Decline Weighted Sit-Up	On decline bench	More resistance from gravity
Weighted Sit-Up + Twist	Rotate at top	Oblique emphasis
Weighted V-Up	Legs and torso up	Advanced coordination

By Target

Target	Variation	Change
Full Abs	Standard version	Balanced approach
Obliques	Add twist at top	Rotate torso left/right
Strength	Heavier weight, lower reps	Progressive overload
Endurance	Lighter weight, high reps	20-30 reps

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📊 Programming

Rep Ranges by Goal

Goal	Sets	Reps	Rest	Weight
Strength	4	6-10	90-120s	Heavy (25-45+ lbs)
Hypertrophy	3-4	10-15	60-90s	Moderate (10-25 lbs)
Endurance	2-3	15-25	45-60s	Light (5-15 lbs)

Workout Placement

Program Type	Placement	Rationale
Core day	Primary	Main ab exercise
Full body	Supplementary	After main lifts
Circuit training	Station	Part of rotation

Progression Scheme

How to Progress

Increase weight in 5 lb increments when you can complete 3x15 with good form. Or progress to decline version or overhead hold.

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🔄 Alternatives & Progressions

Exercise Progression Path

Regressions (Easier)

Exercise	When to Use
Bodyweight Sit-Up	First learning sit-ups
Crunch	Want ab isolation only
Dead Bug	Building core control

Progressions (Harder)

Exercise	When Ready
Decline Weighted Sit-Up	Flat version too easy
Weighted V-Up	Want full-body core challenge
Cable Crunch	Want variable resistance

Alternatives

Alternative	When to Use
Cable Crunch	Have cable machine
Ab Wheel Rollout	Different movement pattern
Hanging Leg Raise	Lower ab focus

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🛡️ Safety & Contraindications

Who Should Be Careful

Condition	Risk	Modification
Lower back issues	Spinal flexion under load	Avoid or use very light weight
Neck problems	Strain during movement	Don't pull on neck, keep neutral
Disc herniation	Flexion compresses discs	Avoid — use neutral spine exercises
Pregnancy	Supine position after 1st trimester	Avoid flat on back

Stop Immediately If

• Sharp pain in lower back
• Neck pain or strain
• Dizziness
• Any unusual popping or clicking in spine

Safety Tips

• Start with very light weight — 5-10 lbs max
• Progress weight slowly (5 lb increments)
• Keep weight close to body
• If feet lift, anchor them or have partner help
• Avoid if you have disc issues

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🦴 Joints Involved

Joint	Action	ROM Required	Stress Level
Spine	Flexion (entire spine)	Full	🟡 Moderate-High
Hip	Flexion	Moderate	🟢 Low

Joint Health

If you have lower back issues, stick to crunches (partial ROM) or anti-extension exercises like planks instead of full sit-ups.

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❓ Common Questions

Are sit-ups bad for your back?

Not inherently, but they do involve spinal flexion under load. If you have existing back issues (especially disc problems), avoid them. For healthy individuals, weighted sit-ups are fine when done with proper form and appropriate weight.

How much weight should I start with?

Start with 5-10 lbs (a light plate or dumbbell). This might seem easy, but the goal is perfect form first. You can always add weight.

Where should I hold the weight?

At your chest is standard and most comfortable. Holding it overhead makes it harder (longer lever arm). Avoid holding it behind your head as this can cause neck strain.

How is this different from a crunch?

A sit-up is full range of motion — you curl all the way up to sitting. A crunch is partial ROM — shoulders lift but lower back stays on ground. Sit-ups engage more hip flexors; crunches isolate abs more.

My neck hurts during sit-ups — what do I do?

Don't pull on your neck. Keep your head neutral, aligned with your spine. Hold the weight at your chest, not behind your head. If neck pain persists, stick to crunches instead.

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📚 Sources

Biomechanics & Muscle Activation:

• Escamilla, R.F., et al. (2006). Core exercise muscle activation — Tier A
• ExRx.net — Tier C

Programming:

• NSCA Essentials — Tier A
• ACE Exercise Library — Tier B

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For Mo

When to recommend this exercise:

• User wants to build ab strength with progressive overload
• User has mastered bodyweight sit-ups
• User wants a classic, simple core exercise
• User has weights available

Who should NOT do this exercise:

• Disc herniation or acute back injury → Avoid flexion under load
• Severe neck problems → Risk of strain
• Pregnancy (after 1st trimester) → Avoid supine position
• Complete beginner → Start with crunches or planks

Key coaching cues to emphasize:

1. "Roll up vertebra by vertebra"
2. "Weight stays at chest — don't let it drift"
3. "Control the descent — 2-3 seconds down"

Common issues to watch for in user feedback:

• "My neck hurts" → Check head position, don't pull on neck
• "My feet lift off" → Anchor feet or use lighter weight
• "Too easy" → Add 5 lbs or progress to decline
• "Back hurts" → May be too much weight, check form or regress to bodyweight

Programming guidance:

• For beginners: Start 5-10 lbs, 3 sets of 10-12 reps
• For intermediates: 15-25 lbs, 3-4 sets of 10-15 reps
• Progress when: Can do 3x15 with perfect form
• Advance by: Adding 5 lbs, or progressing to decline version

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Last updated: December 2024