The 3-Set Rule: Unpacking the Gym's Most Famous Tradition (And Why 2 Sets Might Be Your New Best Friend)
Walk into any gym in the world, and you'll see it. Someone sits down on a bench, performs a set of exercises, rests, and repeats it two more times. The three-set structure is as fundamental to the gym as dumbbells and protein shakes. We all do it, but have you ever stopped to ask why?
Is three some magical number for muscle growth? Is it a sacred rule passed down through generations of bodybuilders?
The truth is a little more practical and has its roots in post-war rehabilitation, not a quest for the perfect physique. Today, we'll dig into the history of the 3-set rule, why it works, and how a modern, time-efficient alternative of just two sets can be incredibly effective.
A Quick History Lesson: The DeLorme Protocol
The popularisation of "3 sets of 10" can be traced back to the 1940s and an American army physician named Dr. Thomas DeLorme. He was tasked with rehabilitating soldiers who had suffered orthopaedic injuries during World War II.
He developed a system of progressive resistance exercise to help them regain strength. His original protocol, known as the "DeLorme Method," involved:
Set 1: 10 reps at 50% of the patient's 10-repetition maximum (10RM).
Set 2: 10 reps at 75% of their 10RM.
Set 3: 10 reps at 100% of their 10RM (i.e., to their maximum effort).
This system was incredibly effective for building strength and muscle in recovering soldiers. It was structured, progressive, and easy to follow. As soldiers returned to civilian life and fitness culture grew, this effective rehabilitation protocol morphed into the general fitness standard we see today.
Why 3 Sets Became the Gold Standard
Let's be clear: the three-set method is popular for a reason. It works! Here’s why it has stood the test of time:
Sufficient Volume: For muscle growth (hypertrophy), you need to create enough stress and stimulus. Three challenging sets provide a solid amount of training volume to trigger the muscle-building process.
Practice and Pacing: The first set can act as a final warm-up or a "feeler" set, allowing you to gauge your strength for the day. The second and third sets are where you can really push the intensity.
The "Sweet Spot": For many people, it’s a manageable amount of work. It’s enough to be effective without causing excessive fatigue that could ruin the rest of your workout.
But the key word here is effective, not essential. The fitness world has evolved, and we now understand that the quality and intensity of your sets often matter more than the quantity.
The Alternative: Making 2 Sets Work For You
For the busy professional, the parent juggling a dozen tasks, or anyone just looking to be more efficient, spending less time in the gym is a huge win. The good news is that you can get fantastic results from just two working sets per exercise, provided you do it right.
The goal is to trade volume for intensity. If you're going to do fewer sets, you have to make each one count. Here’s how:
1. Warm-Up is Non-Negotiable
This plan is for two working sets. This does not include your warm-up. Before you start your first main exercise, do one or two light sets with about 50% of your working weight to prepare your muscles, joints, and nervous system for the effort to come.
2. Train Close to Failure
This is the most important rule. If you're only doing two sets, you can't leave much in the tank. We measure this using Reps in Reserve (RIR). This is how many more reps you feel you could have done with perfect form at the end of a set.
For your two sets to be effective, you should aim for an RIR of 1-2.
This means that at the end of each set, you should feel like you could have only managed one or two more reps before your form broke down or you couldn't complete the lift. This high level of effort ensures you're creating enough mechanical tension to stimulate muscle growth.
3. Perfect Your Form
With higher intensity comes a higher risk if your form is sloppy. Focus on a full range of motion and controlling the weight on the way down (the eccentric portion). Better form not only prevents injury but also ensures the target muscle is doing the work.
4. Apply Progressive Overload
The fundamental rule of getting stronger never changes. You still need to challenge your body more over time. With a two-set system, you can:
Add a little more weight than last time.
Try to get one more rep than you did previously with the same weight.
Improve your form or slow down the eccentric part of the lift.
The Takeaway
There is nothing wrong with doing 3 sets. It's a proven, effective method that has helped millions of people get stronger.
However, it's not the only way. For those who are short on time or who want to increase their training intensity, switching to two hard, focused sets can be a game-changer. You save time, reduce overall fatigue, and can pour all your energy into making every single rep count.
The best workout plan is the one you can stick to consistently. If a more efficient, two-set approach means you'll be more consistent, then it’s the perfect plan for you.
Ready to build a smarter, more efficient workout plan tailored to your goals and schedule? Contact me today for a free consultation!