By Will Duru, BSc (Hons) Sport and Exercise Science, Award winning Personal Trainer with over 10 years of experience in strength training
My legs were my weak point for years. I trained them. I squatted. I pressed. But they never grew the way my upper body did. I looked like someone who skipped leg day even though I never skipped leg day.
Then I tried Arnold’s leg workout.
After 12 weeks of following his approach, my legs finally responded. My quads developed sweep I had never seen before. My hamstrings filled out. Even my calves, which had been stubborn for a decade, started to grow.
The secret was not a magic exercise. It was the volume, the intensity, and the short rest periods that Arnold was famous for. His leg day is brutal. It will test your mental strength as much as your physical strength. But it works.
Here is exactly what I did and why it delivered results when nothing else had.
Why My Legs Were Not Growing Before
Before I dive into the programme, let me explain what I was doing wrong. This might sound familiar to you.
I was training legs once per week. I would do squats, leg press, leg curls, and call it done. Four exercises, three sets each, two to three minutes rest between sets. Standard stuff.
The problem was that my legs had adapted to this stimulus years ago. I was maintaining, not building. The volume was too low. The rest periods were too long. The intensity was not enough to force new growth.
Arnold understood something that most lifters miss. Legs are the largest muscle group in the body. They can handle more volume than your chest or arms. They need more volume to grow.
His leg day reflects this understanding.
The Arnold Leg Day Workout
This is the exact workout I followed for 12 weeks. I ran it twice per week, typically on Wednesday and Saturday, with at least two days between sessions.
Squats: The Foundation
Arnold called squats the king of exercises. He was not wrong. Every leg session started with heavy squats.
| Exercise | Sets | Reps | Rest |
|---|---|---|---|
| Barbell Back Squats | 5 | 12, 10, 8, 8, 6 | 90 seconds |
The rep scheme is important. You start with a lighter weight for 12 reps to warm up the movement pattern and get blood into the muscles. Then you add weight and drop reps as you progress through the sets.
By the final set of 6, you should be working close to your limit. If you can do 8 reps on that last set, the weight was too light.
I used the 12REPS app to track my squat numbers each session. Seeing my previous weights made it easy to know exactly what to load on the bar.
Leg Press: Building Volume
After squats, your legs are already fatigued. That is the point. The leg press allows you to continue building volume without the stability demands of a barbell on your back.
| Exercise | Sets | Reps | Rest |
|---|---|---|---|
| Leg Press | 4 | 12, 10, 10, 8 | 60 seconds |
Notice the shorter rest period. Arnold used 60 seconds or less on leg press to keep the intensity high and maintain the pump in his quads.
The leg press should be done with a full range of motion. Lower the sled until your knees are at 90 degrees or slightly below. Half reps will give you half results.
Superset: Leg Extensions and Leg Curls
This is where the workout gets brutal. Arnold loved supersets for legs because they extend the time under tension and create massive metabolic stress.
| Exercise | Sets | Reps | Rest After Superset |
|---|---|---|---|
| Leg Extensions | 4 | 15, 12, 12, 10 | None |
| Lying Leg Curls | 4 | 12, 10, 10, 10 | 60 seconds |
Perform your leg extensions, walk directly to the leg curl machine, perform your leg curls, then rest 60 seconds. Repeat four times.
By the third superset, your legs will be screaming. By the fourth, you will question why you ever started this programme. Push through it.
Romanian Deadlifts: Hamstring Focus
Arnold did not neglect his hamstrings. Strong hamstrings balance the quads and protect the knees. Romanian deadlifts were a staple in his leg training.
| Exercise | Sets | Reps | Rest |
|---|---|---|---|
| Romanian Deadlifts | 4 | 12, 10, 10, 8 | 90 seconds |
Keep a slight bend in your knees and hinge at the hips. Feel the stretch in your hamstrings at the bottom of the movement. Squeeze your glutes and hamstrings to return to standing.
Walking Lunges: Functional Strength
Lunges build single leg strength and stability. They also keep your heart rate elevated and add conditioning work to the session.
| Exercise | Sets | Reps | Rest |
|---|---|---|---|
| Walking Lunges | 3 | 20 steps per set | 60 seconds |
Use dumbbells or a barbell across your back. Twenty steps means ten lunges per leg. Keep your torso upright and your front knee tracking over your toes.
Superset: Standing and Seated Calf Raises
Arnold had famously underdeveloped calves early in his career. He addressed this by training them with extreme volume and frequency. This superset attacks the calves from two angles.
| Exercise | Sets | Reps | Rest After Superset |
|---|---|---|---|
| Standing Calf Raises | 5 | 15, 15, 12, 12, 10 | None |
| Seated Calf Raises | 5 | 15, 15, 12, 12, 10 | 45 seconds |
Standing calf raises target the gastrocnemius, the larger calf muscle. Seated calf raises target the soleus, which sits underneath. You need both for complete calf development.
Five supersets of calf work is a lot. Your calves will burn. This is exactly why most people have small calves. They are not willing to do the work.
The Complete Workout at a Glance
| Exercise | Sets | Reps | Rest |
|---|---|---|---|
| Barbell Back Squats | 5 | 12, 10, 8, 8, 6 | 90 seconds |
| Leg Press | 4 | 12, 10, 10, 8 | 60 seconds |
| Leg Extensions (superset) | 4 | 15, 12, 12, 10 | None |
| Lying Leg Curls (superset) | 4 | 12, 10, 10, 10 | 60 seconds |
| Romanian Deadlifts | 4 | 12, 10, 10, 8 | 90 seconds |
| Walking Lunges | 3 | 20 steps | 60 seconds |
| Standing Calf Raises (superset) | 5 | 15, 15, 12, 12, 10 | None |
| Seated Calf Raises (superset) | 5 | 15, 15, 12, 12, 10 | 45 seconds |
Total working sets: 34 Estimated time: 70 to 80 minutes
What I Learned Over 12 Weeks
Running this programme twice per week for three months taught me lessons that changed how I approach leg training.
The Short Rest Periods Are Essential
I cannot stress this enough. The magic of this workout is in the short rest periods. When I first started, I wanted to rest longer. My legs were burning. My lungs were struggling. Every instinct told me to wait until I felt ready.
But I used a timer. When 60 seconds was up, I started my next set regardless of how I felt. This discipline is what creates the stimulus for growth.
I set rest timers in the 12REPS app and let it tell me when to go. Taking the decision out of my hands made it easier to stick to the programme.
Train When the Gym Is Quiet
The supersets require you to move between machines quickly. In a busy gym, someone will take the leg curl machine while you are doing leg extensions. Someone will claim the seated calf raise while you are on the standing version.
I trained early morning when my gym was nearly empty. This allowed me to set up my supersets properly and move between exercises without interruption.
Find your gym’s quiet hours. Protect that time for leg day.
Track Every Session
The volume of this workout generates a lot of data. Weights, reps, sets, rest periods. If you try to remember it all, you will miss details and your progression will suffer.
I logged every workout in the 12REPS app. Before each exercise, I could see exactly what I did last time. This made progressive overload simple and consistent.
Looking back over 12 weeks of data, I could see clear improvement. My squat went from 100kg for 6 reps to 120kg for 6 reps. My leg press increased by 40kg. Even my calf raises showed steady progression.
Eat More Than You Think You Need
Leg training burns a massive amount of calories. The large muscle groups require significant energy to train and recover.
During these 12 weeks, I increased my food intake substantially. More protein to support muscle repair. More carbohydrates to fuel the intense sessions. More total calories to support the volume.
If you run this programme on a calorie deficit, you will struggle to recover and your results will suffer. Eat to grow.
Expect Serious Soreness Initially
The first two weeks were brutal. I experienced delayed onset muscle soreness like I had not felt in years. Walking up stairs was difficult. Sitting down required lowering myself carefully.
This is normal when you introduce a new stimulus. Your body is not adapted to this volume yet. Push through the initial soreness. By week three, the soreness reduced significantly as my body adapted.
Take a Deload When Needed
By week seven, I was feeling accumulated fatigue. My motivation was dropping. My strength in the squat had plateaued.
I took a deload week. Same exercises, but I reduced the weight by 40% and cut the sets in half. This active recovery week allowed my body to catch up with the training stress.
The following week, I came back stronger and broke through my plateau. Listen to your body. Strategic deloads are part of intelligent training.
My Results After 12 Weeks
Here is what changed after three months of Arnold’s leg day:
Quad development: Visible sweep developed on the outer quad. My legs looked bigger from the front and the side.
Hamstring size: My hamstrings filled out noticeably. The back of my legs had definition I had never achieved before.
Calf growth: My calves finally responded. After years of being stubbornly small, they added measurable size.
Squat strength: My working sets increased from 100kg to 120kg for the same rep range.
Leg press strength: Increased by 40kg across all sets.
Overall leg size: My trousers fit tighter through the thighs. I had to buy new jeans.
The visual change was dramatic enough that people commented on it. For someone whose legs had been a weak point for years, this was exactly what I needed.
Why This Workout Works
The Arnold leg day works because it addresses the three main drivers of muscle growth.
Mechanical Tension
The heavy squats and leg presses create significant mechanical tension on the muscle fibres. This tension signals your body to build stronger, larger muscles to handle the load.
Metabolic Stress
The short rest periods and supersets create metabolic stress. This is the burning sensation you feel when lactate and other metabolic byproducts accumulate in the muscle. Research shows this metabolic stress contributes to hypertrophy.
Muscle Damage
The high volume creates controlled muscle damage. Your body repairs this damage by building the muscle back stronger and larger. This is why the initial soreness is so intense and why the results follow.
Most leg workouts only address one or two of these factors. Arnold’s approach hits all three, which is why it delivers superior results.
Who Should Try This Programme
This workout is appropriate for intermediate and advanced lifters who have plateaued on their current leg training. You should have:
At least one year of consistent training experience. The volume is high and the exercises demand solid technique.
Good squat form. If your squat technique breaks down under fatigue, you need to address that before adding this much volume.
Time to train properly. Each session takes 70 to 80 minutes. If you only have 30 minutes, this is not the programme for you.
Willingness to be uncomfortable. This workout is hard. Your legs will burn. Your lungs will work. You need mental toughness to push through.
If you are a beginner, start with a simpler programme first. Build your foundation, learn the movements, develop your work capacity. The 12REPS app has beginner programmes that will prepare you for this level of training.
Who Should Avoid This Programme
Complete beginners. You need a foundation of strength and technique first.
Those recovering from knee or back injuries. The volume and intensity are high. Make sure you are fully cleared before starting.
People who cannot train legs twice per week. The programme is designed for twice weekly frequency. Once per week will not deliver the same results.
Those who cannot commit to the rest periods. If you are going to take three minutes between sets, do not bother. The short rest is essential.
How to Get Started
Download the 12REPS app and set up the workout with your starting weights. Use the app to track every session and time your rest periods.
Start with weights you can handle with good form. The first week is about learning the flow of the workout, not setting personal records.
Add weight progressively when you can complete all reps with good form. Small increases add up over 12 weeks.
Commit to the full programme. Trust the process. Watch your legs grow.
Frequently Asked Questions
How often should I do this leg workout?
Twice per week with at least two days between sessions. This allows adequate recovery while providing enough frequency for optimal growth.
Can I do this workout once per week?
You can, but results will be slower. Twice weekly frequency is superior for muscle growth based on current research.
What if I cannot do all the sets?
Start with fewer sets and build up over several weeks. It is better to complete the workout with reduced volume than to burn out halfway through.
Should I do cardio on the same day?
No. The workout is demanding enough. Save cardio for rest days or do light walking only.
How long until I see results?
Most people notice changes around week four to six. Significant visual changes typically appear by week eight to twelve.
What if my gym does not have all the equipment?
Substitute similar exercises. Hack squats can replace leg press. Dumbbell Romanian deadlifts work if you do not have a barbell. The principles matter more than the specific equipment.
References
- Schoenfeld, B.J. (2010). The mechanisms of muscle hypertrophy and their application to resistance training. Journal of Strength and Conditioning Research. https://pubmed.ncbi.nlm.nih.gov/20847704/
- Schoenfeld, B.J. et al. (2016). Effects of Resistance Training Frequency on Measures of Muscle Hypertrophy. Sports Medicine. https://pubmed.ncbi.nlm.nih.gov/27102172/
- de Souza, T.P. et al. (2010). Comparison between constant and decreasing rest intervals: influence on maximal strength and hypertrophy. Journal of Strength and Conditioning Research. https://pubmed.ncbi.nlm.nih.gov/20300015/
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About the Author: Will Duru holds a BSc (Hons) in Sport and Exercise Science and is an award -winning personal trainer with over 10 years of experience. He followed Arnold’s leg day for 12 weeks and finally achieved the leg development that had eluded him for years. Will created the 12REPS app to help others track their training and achieve similar results.
