Seated Leg Curl

The constant tension hamstring builder — unique seated position maximizes hamstring activation throughout entire range of motion

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⚡ Quick Reference

Aspect	Details
Pattern	Hinge (Isolation)
Primary Muscles	Hamstrings
Secondary Muscles	Calves
Equipment	Seated Leg Curl Machine
Difficulty	⭐ Beginner
Priority	🟠 Common

Movement Summary

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🎯 Setup

Starting Position

1. Back pad adjustment: Set back rest so knees align with machine's pivot point when seated
2. Leg pad position: Bottom pad should rest just above heels/Achilles
3. Thigh pad: Upper pad should secure thighs firmly but comfortably
4. Seat position: Hips should be slightly behind the knee pivot point
5. Weight selection: Start conservative — hamstrings fatigue quickly
6. Grip handles: Hold side handles for stability
7. Starting position: Legs extended (but not locked), pad against lower calves

Equipment Setup Details

Component	Setting	Purpose
Back pad	Upright to slight recline	Prevents sliding, maintains position
Knee/Pivot alignment	Knees at or slightly behind pivot	Proper resistance curve
Leg pad height	Just above ankles	Maximum hamstring leverage
Thigh pad pressure	Firm but not painful	Isolates hamstrings, prevents hip movement

Critical Setup Point

Knee alignment with machine pivot is crucial. If your knees are too far forward of the pivot, you lose tension at peak contraction. Too far back, and you get excessive knee stress. Adjust the seat forward/back until knees align perfectly.

Pre-Exercise Checklist

• Back is flat against pad
• Knees aligned with machine's rotation point
• Thigh pad secured (can't lift legs up)
• Leg pad positioned just above heels
• Slight bend in knees (not locked out)
• Hands on handles for stability
• Weight stack selected and pin inserted

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🔄 Execution

The Movement

🎯 Starting Position

What's happening: Full leg extension with tension on hamstrings

1. Legs extended with slight bend in knees
2. Pad resting against lower calves/Achilles area
3. Thighs secured under pad
4. Back flat against back rest
5. Core engaged to prevent movement
6. Already feeling slight hamstring stretch

Breathing: Inhale, prepare to curl

Feel: Light tension in hamstrings, ready to pull

Critical: Don't lock knees completely — maintain slight bend

⬆️ Concentric (Curling) Phase

What's happening: Hamstrings contract to bring heels toward body

1. Curl heels down and back — pull with hamstrings
2. Drive heels toward buttocks
3. Keep upper body stable — no rocking
4. Maintain pressure against thigh pad
5. Continue until maximum hamstring contraction
6. Breathing: Exhale as you curl

Tempo: 1-2 seconds (controlled, powerful)

Feel: Intense hamstring contraction, burning sensation

Cue: "Pull heels to butt" — simple, effective

Peak contraction position: Heels as close to buttocks as possible, hamstrings fully shortened

💥 Peak Contraction

What's happening: Maximum hamstring shortening

1. Heels pulled as far back as possible
2. Squeeze hamstrings hard — 1-2 second hold
3. Maintain stability in upper body
4. Don't let thigh pad lift
5. Feel the burn intensify

Why this matters: Seated position allows unique peak contraction that lying curls can't achieve

Advanced technique: Pause here for 2-3 seconds for enhanced muscle activation

⬇️ Eccentric (Lowering) Phase

What's happening: Controlled resistance against weight stack

1. Slowly extend legs — resist the weight
2. Don't let weight stack crash down
3. Maintain tension throughout
4. Control the negative for 2-3 seconds
5. Breathing: Inhale as you extend
6. Stop just before full extension

Tempo: 2-3 seconds (slower than concentric)

Feel: Hamstrings lengthening under tension, maintaining burn

Critical: Eccentric phase builds strength and size — don't rush it!

End position: Return to starting position with slight knee bend, NOT fully locked

Key Cues

Primary Cues

• "Pull heels to butt" — focuses on hamstring action
• "Squeeze at the top" — maximizes peak contraction
• "Control the negative" — emphasizes eccentric strength
• "Stay glued to the pad" — prevents momentum/cheating

Secondary Cues for Common Issues

Issue	Cue	Fix
Using momentum	"No rocking"	Focus on stability
Partial ROM	"Heels to butt"	Full contraction
Too fast	"2 seconds down"	Control eccentric
Hip movement	"Thighs stay down"	Maintain position

Tempo Guide

Training Focus	Concentric	Pause	Eccentric	Rest
Strength	1-2s	1s	2-3s	0s
Hypertrophy	2s	2s	3s	1s
Endurance	1s	0s	2s	0s
Time Under Tension	2-3s	2-3s	4-5s	0s

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💪 Muscles Worked

Activation Overview

Primary Movers

Muscle	Action	Activation
Hamstrings	Knee flexion — primary and sole driver	██████████ 95%

Hamstring Breakdown:

• Biceps Femoris (Short & Long Head): 95% activation
• Semitendinosus: 95% activation
• Semimembranosus: 95% activation

Secondary Muscles

Muscle	Action	Activation
Gastrocnemius (Calves)	Assist knee flexion, minor role	█████░░░░░ 45%

Why Calves Are Involved

The gastrocnemius (calf muscle) crosses both the ankle AND knee joint. During leg curls, it assists with knee flexion. This is why you might feel a calf pump during high-rep leg curls.

Stabilizers

Muscle	Role	Activation
Core	Prevent trunk movement	███░░░░░░░ 25%
Hip flexors	Maintain hip position	██░░░░░░░░ 20%

Unique Advantage of Seated Position

The seated leg curl provides unique biomechanical advantage:

1. Hip flexion (bent hip) pre-stretches hamstrings — creates greater ROM
2. Constant tension throughout entire movement — weight doesn't rest at any point
3. Peak contraction intensity — better than lying variation at top of movement
4. Reduced lower back involvement — safer for those with back issues

Comparison to Lying Leg Curl:

• Seated: Better peak contraction, more glute/hip stability required
• Lying: Better stretch at bottom, slightly easier to handle heavy weight

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⚠️ Common Mistakes

Mistake	What Happens	Why It's Bad	Fix
Lifting hips/butt off seat	Using hip extension to assist	Defeats isolation purpose, less hamstring work	"Glue your butt to the seat," reduce weight
Swinging/momentum	Rocking torso forward and back	Removes constant tension, injury risk	Lighter weight, hold handles, focus on control
Partial range of motion	Not curling heels all the way back	Misses peak contraction benefits	"Heels to butt," reduce weight if needed
Locking knees at extension	Fully straightening legs at top	Removes tension, joint stress	Keep slight bend at extension
Too much weight	Can't control eccentric	Form breakdown, reduced effectiveness	Ego check — hamstrings respond to control, not weight
Jerky/fast reps	Explosive movement both directions	Reduces time under tension, injury risk	"Smooth and controlled" — count tempo
Toes pointing down	Plantar flexion of ankle	Can cause calf cramping	Keep toes neutral or slightly up

Most Common Beginner Error

Using momentum by rocking the torso: This is the #1 form breakdown on seated leg curls. If you find yourself swinging forward as you curl, you're using too much weight. The thigh pad should lock you in place — if you're moving around it, drop the weight.

Self-Check Checklist

• Hips/butt stay firmly against seat (no lifting)
• Upper body remains stable (no rocking)
• Full range of motion (heels to butt, then controlled extension)
• Squeeze/pause at peak contraction
• Controlled eccentric (2-3 seconds minimum)
• Slight bend maintained at full extension (knees not locked)
• Breathing is controlled and rhythmic

Form Self-Assessment

During your set, ask yourself:

1. Am I moving anything other than my lower legs? (Should be NO)
2. Can I pause at the top and squeeze? (Should be YES)
3. Is the weight stack slamming? (Should be NO)

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🔀 Variations

By Leg Position

Standard (Both Legs)

Feature	Description
Position	Both legs curl simultaneously
Benefit	Balanced development, can handle more weight
Best for	General hamstring development, beginners

Standard variation — start here.

Single Leg

Feature	Description
Position	One leg at a time
Benefit	Fixes imbalances, greater mind-muscle connection
Best for	Correcting asymmetries, advanced training

Progression: Use about 40-50% of your bilateral weight per leg

Link: Single-Leg Seated Curl

Alternating Legs

Feature	Description
Position	Alternate right-left-right-left
Benefit	Continuous tension, metabolic stress
Best for	Conditioning, hypertrophy finishers

Advanced technique: One leg curls while other extends — constant work

By Foot/Ankle Position

Neutral (Standard)

Position	Effect	Use
Toes pointing straight	Balanced hamstring activation	Default position

Toes Out (Externally Rotated)

Position	Effect	Use
Toes turned outward	Emphasizes inner hamstrings (semimembranosus, semitendinosus)	Variety, inner hamstring focus

Angle: 30-45° outward rotation

Toes In (Internally Rotated)

Position	Effect	Use
Toes turned inward	Emphasizes outer hamstrings (biceps femoris)	Variety, outer hamstring focus

Angle: 30-45° inward rotation

Note: Subtle differences — use primarily for variety and addressing specific weaknesses

Advanced Training Variations

Variation	Modification	Purpose	Difficulty
Pause reps	2-5 second hold at peak contraction	Enhanced muscle activation	⭐⭐
1.5 reps	Full curl + half extension + full curl = 1 rep	Increased time under tension	⭐⭐⭐
Tempo reps	4-5 second eccentric	Eccentric strength, hypertrophy	⭐⭐
Drop sets	Reduce weight immediately after failure, continue	Metabolic stress, muscle growth	⭐⭐⭐
Partial reps	Top half ROM only	Peak contraction overload	⭐⭐
Isometric holds	Hold at various angles (90°, 45°)	Strength at specific points	⭐⭐

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📊 Programming

Rep Ranges by Goal

Goal	Sets	Reps	Rest	Tempo	RIR
Strength	3-4	8-12	90-120s	2-1-2-0	2-3
Hypertrophy	3-5	10-15	60-90s	2-2-3-0	1-2
Endurance	2-3	15-20+	45-60s	1-0-2-0	2-3
Pump/Finisher	2-3	12-15	30-45s	1-1-2-0	0-1

Workout Placement

Program Type	Placement	Volume	Rationale
Leg day	After compounds	3-4 sets	Isolation after squats/deadlifts
Hamstring focus	First or second	4-5 sets	When fresh, can push harder
Push-Pull-Legs	Pull day	3 sets	Pairs with back work
Upper-Lower	Lower day	3-4 sets	After main lifts
Full-body	End of workout	2-3 sets	Accessory work

Pairing Suggestions

Supersets (same muscle group):

• Seated Leg Curl → Lying Leg Curl — different angles
• Seated Leg Curl → Nordic Curl (eccentric) — machine + bodyweight

Antagonist supersets:

• Seated Leg Curl → Leg Extension — hamstrings + quads
• Seated Leg Curl → Leg Press — isolation + compound

Circuit options:

• Leg Extension → Seated Leg Curl → Calf Raise — complete lower leg

Frequency Guidelines

Training Level	Frequency	Weekly Volume
Beginner	1-2x/week	6-9 sets total
Intermediate	2x/week	9-15 sets total
Advanced	2-3x/week	12-20 sets total

Progression Scheme

Progressive overload methods:

1. Weight: Add 5-10 lbs when hitting top of rep range
2. Reps: Add 1-2 reps per set with same weight
3. Sets: Add 1 set per session
4. Tempo: Slower eccentric (2s → 3s → 4s)
5. Rest: Reduce rest periods (90s → 75s → 60s)
6. Variations: Progress to single-leg version

Hamstring Progression Note

Hamstrings respond exceptionally well to both progressive overload AND training variety. Alternate between weight progression and variation changes (bilateral → single leg, neutral foot → toes out/in) for best results.

Sample Hamstring Training Day

Option 1: Strength Focus

1. Romanian Deadlift — 4x6-8 (compound)
2. Seated Leg Curl — 4x8-12 (isolation)
3. Nordic Curl (assisted) — 3x6-8 (eccentric emphasis)

Option 2: Hypertrophy Focus

1. Lying Leg Curl — 4x10-12 (different angle)
2. Seated Leg Curl — 4x12-15 (constant tension)
3. Single-Leg RDL — 3x10/leg (stability + hamstring)

Option 3: Isolation Emphasis

1. Seated Leg Curl — 5x12-15 (primary movement)
2. Seated Leg Curl (single-leg) — 3x10-12/leg (fix imbalances)
3. Seated Leg Curl (pause reps) — 2x8-10 (finisher)

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🔄 Alternatives & Progressions

Exercise Progression Path

Regressions (Easier)

Exercise	When to Use	Benefit	Link
Slider Leg Curl	No machine access	Bodyweight option, home-friendly	✓
Swiss Ball Leg Curl	Build base strength	Easier, scalable	✓
Resistance Band Leg Curl	Very beginner, rehab	Light resistance, portable	✓

Progressions (Harder)

Exercise	When Ready	Challenge	Link
Single-Leg Seated Curl	Fix imbalances, increase difficulty	One leg at a time	✓
Nordic Curl (assisted)	Build eccentric strength	Bodyweight eccentric	✓
Glute-Ham Raise	Elite hamstring strength	Full posterior chain	✓

Alternatives (Different Equipment, Same Goal)

Machine Alternatives

Alternative	Key Difference	When to Use
Lying Leg Curl	Prone position, different strength curve	Better stretch at bottom
Standing Leg Curl	One leg at a time, standing	Fix imbalances, limited equipment
Leg Curl (cable)	Cable attachment	Gym variety, adjust resistance curve

Bodyweight Alternatives

Alternative	Equipment Needed	Difficulty
Nordic Curl	Ankle anchor	Very advanced
Slider Leg Curl	Sliders or towel	Intermediate
Swiss Ball Leg Curl	Stability ball	Beginner-Intermediate

Compound Alternatives

Alternative	Movement Pattern	Additional Benefits
Romanian Deadlift	Hip hinge	Full posterior chain, functional
Single-Leg RDL	Hip hinge, unilateral	Balance, stability
Glute-Ham Raise	Hip + knee flexion	Elite strength builder

When to Choose Seated vs Other Leg Curls

Choose Seated Leg Curl when:

• You want maximum peak contraction intensity
• You have lower back issues (most supportive position)
• You want constant tension throughout ROM
• You're doing higher rep ranges (15-20+)

Choose Lying Leg Curl when:

• You want better stretch at the bottom position
• You need to lift heavier weight
• You prefer prone position for comfort

Choose Standing Leg Curl when:

• You want to work one leg at a time
• You need functional/balance component
• You only have standing curl machine

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🛡️ Safety & Contraindications

Who Should Be Careful

Condition	Risk	Modification
Acute hamstring strain	Re-injury, delayed healing	Wait until fully healed, start very light
Recent knee surgery	Excessive knee flexion stress	Get medical clearance first
Hamstring tendinopathy	Aggravation of insertion points	Reduce range of motion, lighter weight
Calf cramps	Gastrocnemius involvement	Adjust ankle position, hydration
Lower back pain	Seated position may compress spine	Usually fine due to back support, but monitor

Stop Immediately If

• Sharp pain in hamstring (beyond normal muscle burn)
• Pain behind the knee
• Sudden cramping that won't release
• Popping or tearing sensation
• Pain in lower back during movement

Injury Prevention

How Seated Leg Curls Can PREVENT Hamstring Injuries:

1. Eccentric strength: Controlled negatives build resilience against strains
2. Muscle balance: Strengthens hamstrings to balance quad dominance
3. Tendon health: Regular loading promotes tendon adaptation
4. Range of motion: Maintains hamstring flexibility under load

Proper Programming for Injury Prevention:

• Include leg curls 2x per week minimum
• Don't skip the eccentric phase — it's where injury prevention happens
• Gradually progress weight over weeks/months
• Maintain balanced quad-to-hamstring ratio (hamstrings should be 50-70% of quad strength)

Cramping Prevention

If you experience hamstring or calf cramps during leg curls:

1. Hydration: Drink water before training
2. Electrolytes: Ensure adequate sodium, potassium, magnesium
3. Warm-up: 5-10 minutes of light cardio first
4. Stretch between sets: Gentle hamstring and calf stretches
5. Ankle position: Try pointing toes up (dorsiflexion) to reduce calf involvement
6. Weight selection: May be going too heavy too soon

Safe Loading Guidelines

Training Age	Starting Weight	Weekly Progression
First time	15-25% of body weight	+5 lbs per week
Beginner (< 6 months)	25-40% of body weight	+5-10 lbs per week
Intermediate	40-60% of body weight	+5-10 lbs when ready
Advanced	60%+ of body weight	Progressive as needed

Safety First

Hamstrings are prone to strains, especially when fatigued. NEVER push through sharp pain. The difference between productive muscle burn and injury pain is crucial to recognize.

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🦴 Joints Involved

Joint	Action	ROM Required	Stress Level
Knee	Flexion/Extension	90-140° flexion	🟡 Moderate
Hip	Isometric flexion (held bent)	~90° maintained	🟢 Low
Ankle	Variable (neutral to dorsiflexion)	0-10°	🟢 Low

Mobility Requirements

Joint	Requirement	Notes
Knee	Full flexion (140°+)	Needed for complete curl
Hip	90° flexion	Seated position requires this
Hamstring flexibility	Moderate	Tight hamstrings limit ROM

Unique Joint Positioning

The seated leg curl's advantage:

Unlike lying leg curls, the hip is flexed (bent) throughout the exercise. This has important implications:

1. Pre-stretch: Hip flexion puts hamstrings on stretch before you even start curling
2. Greater ROM: You can achieve more knee flexion from this position
3. Different activation: Proximal (upper) hamstrings work harder to maintain hip position
4. Peak contraction: Superior peak contraction compared to lying variation

Biomechanical comparison:

• Lying leg curl: Hips extended (straight), better stretch at bottom
• Seated leg curl: Hips flexed (bent), better contraction at top
• Standing leg curl: Hip neutral, balance component added

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❓ Common Questions

Is seated or lying leg curl better?

Both are excellent; they complement each other. Seated leg curl provides better peak contraction and constant tension due to hip flexion. Lying leg curl provides better stretch at the bottom and may allow heavier weight. Ideally, include both in your program at different times, or choose based on your gym's equipment. If you can only do one, seated is slightly better for hypertrophy due to constant tension.

How much weight should I use on seated leg curl?

Start conservatively. For most people:

• First time: 15-30% of your body weight (e.g., 25-45 lbs for a 150 lb person)
• After a few sessions: 30-50% of body weight
• Intermediate: 50-70% of body weight
• Advanced: 70%+ of body weight

Your hamstrings fatigue quickly on isolation work. Focus on form and full ROM over weight. If you can't do 10 controlled reps with a 2-second eccentric, the weight is too heavy.

Should my toes be pointed, neutral, or flexed?

Default = neutral (toes pointing straight ahead). From there:

• Toes pointed (plantarflexion): Can cause calf cramps — generally avoid
• Toes flexed up (dorsiflexion): Reduces calf involvement, more hamstring isolation
• Toes out (external rotation): Slight emphasis on inner hamstrings
• Toes in (internal rotation): Slight emphasis on outer hamstrings

The differences are subtle. Stick with neutral or toes-up for most training. Use rotation variations for variety.

Why do my calves cramp during leg curls?

Common issue! The gastrocnemius (calf muscle) crosses both the knee and ankle, so it assists during leg curls. Solutions:

1. Point toes up (dorsiflexion) — reduces calf involvement
2. Hydrate properly before training
3. Ensure electrolyte balance (sodium, potassium, magnesium)
4. Warm up with light cardio first
5. Stretch calves between sets
6. Reduce weight — may be going too heavy

If cramping persists, consider lying leg curl instead, which typically causes less calf cramping.

How many times per week should I do leg curls?

Minimum: 1-2x per week Optimal: 2x per week Maximum: 3x per week (for advanced lifters)

Hamstrings recover relatively quickly from isolation work. Most people see best results with 2 sessions per week, allowing 2-3 days between sessions. You can do seated leg curls one session and lying/standing leg curls another session for variety.

Should I do leg curls on leg day or pull day?

Leg day: Most common — after squats/leg press Pull day: Also works well — hamstrings during deadlifts/rows

Either is fine. Choose based on your split:

• Push/Pull/Legs: Leg day, after compounds
• Upper/Lower: Lower day, after squats/deadlifts
• Full body: End of session

Key principle: Do leg curls AFTER compound movements (squats, deadlifts, leg press), not before. Pre-fatiguing hamstrings compromises compound lift performance and safety.

Can I do seated leg curls if I have knee pain?

Maybe. Seated leg curls are generally knee-friendly since there's no impact or weight-bearing. However:

Try first:

• Very light weight (just the stack without added plates)
• Reduced range of motion (don't curl all the way)
• Slow tempo to identify pain points
• Ensure proper machine setup (knee alignment with pivot)

Red flags — stop and see a doctor:

• Sharp pain behind the knee
• Pain that worsens during the movement
• Swelling after training
• Pain during daily activities

Often, strengthening hamstrings actually helps knee health. But acute injuries need medical clearance first.

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📚 Sources

Biomechanics & Muscle Activation:

• Ebben, W.P. (2009). Hamstring Activation During Exercise — Tier A
• Wright, G.A. et al. (1999). Electromyographic Activity of Hamstrings During Different Leg Curl Variations — Tier A
• ExRx.net Exercise Directory — Tier C
• NSCA Exercise Technique Manual — Tier A

Programming & Hypertrophy:

• Schoenfeld, B.J. (2010). The Mechanisms of Muscle Hypertrophy — Tier A
• Renaissance Periodization — Tier B
• Helms, E. et al. (2020). Training Volume Landmarks — Tier A

Injury Prevention:

• van der Horst, N. et al. (2015). Hamstring Injury Prevention — Tier A
• Askling, C.M. et al. (2013). Hamstring Injury Occurrence — Tier A

Exercise Comparison Studies:

• Ebben, W.P. (2009). Leg Curl Variations EMG Comparison — Tier A
• Mohamed, O. et al. (2002). Effects of Muscle Strengthening on Hamstrings — Tier B

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For Mo

When to recommend this exercise:

• User wants to build hamstring size and strength
• User has access to a seated leg curl machine
• User needs hamstring isolation after compound lifts
• User has lower back issues (seated position is very supportive)
• User wants to fix quad/hamstring imbalance
• User is doing push/pull/legs or upper/lower split

Who should NOT do this exercise:

• Acute hamstring injury (recent strain/tear) → Wait until healed and cleared
• Recent knee surgery without medical clearance → Need doctor approval
• No access to machine → Suggest Lying Leg Curl or Nordic Curl

Key coaching cues to emphasize:

1. "Stay glued to the seat — no rocking or lifting your butt"
2. "Pull heels to butt, squeeze hard at the top"
3. "Control the negative — 2-3 seconds down"
4. "Slight bend in knees at full extension — don't lock out"

Common issues to watch for in user feedback:

• "I'm rocking back and forth" → Weight too heavy, need to control movement
• "My calves keep cramping" → Point toes up, check hydration, may be too heavy
• "I don't feel it in my hamstrings" → Check setup (knee alignment), focus on mind-muscle connection
• "Should I do seated or lying?" → Both are great; seated has better peak contraction, lying has better stretch

Programming guidance:

• Pair with: Quad work (leg extension, leg press), compound lifts (squats, deadlifts)
• Avoid before: Heavy squats or deadlifts (don't pre-fatigue hamstrings)
• Typical frequency: 2x per week
• Volume: 3-4 sets of 10-15 reps
• Load progression: Add 5-10 lbs when user can complete all sets/reps with 2 RIR

Progression signals:

• Ready to add weight: Completing all prescribed sets/reps with good form, 2+ RIR
• Ready for single-leg variation: Can control 12-15 reps bilateral with perfect form
• Needs to regress: Form breaking down, using momentum, can't control eccentric

Special notes:

• Seated leg curl is EXCELLENT for hypertrophy — constant tension is ideal for muscle growth
• Great for supersets with quad exercises (leg extension)
• Peak contraction is unique advantage over lying variation
• Machine setup is critical — knee alignment with pivot point matters
• Hamstrings respond well to both heavy and lighter/higher rep work
• Don't neglect eccentric phase — that's where strength and injury prevention come from

Troubleshooting:

• Calf cramps → Point toes up, hydrate, lighter weight
• No hamstring activation → Check machine setup, slow down, focus on squeeze
• Lower back pain → Usually not an issue due to back support, but check posture
• One leg stronger → Add single-leg work to fix imbalance

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Last updated: December 2024