The Best Rep Range?

 

The Best Rep Range for Muscle Growth: What Science Says

When it comes to building muscle, the question of how many reps per set to perform is often debated in the fitness community. Traditionally, the concept of different rep ranges for strength, hypertrophy (muscle growth), and endurance has been simplified into neat categories: 1-5 reps for strength, 6-12 reps for hypertrophy, and 12+ reps for endurance. However, as more scientific research emerges, it becomes clear that things aren’t quite so black-and-white. This article takes a deep dive into the latest research on rep ranges, hypertrophy, and muscle growth, addressing the question: Is there really an optimal rep range for hypertrophy?

Understanding the Basics of Rep Ranges

Rep ranges are often categorized by the type of adaptation you are looking to achieve:

• Strength: 1-5 reps
• Hypertrophy: 6-12 reps
• Endurance: 12+ reps

These are the traditional guidelines most trainers follow. However, recent research suggests that the optimal range for hypertrophy may not be as narrow as once thought. Let's look at some key studies that have expanded our understanding of rep ranges and muscle growth.

Scientific Studies: Expanding the Rep Range for Hypertrophy

A 2021 review paper by Schoenfeld and colleagues investigated the effects of various rep ranges on hypertrophy and found that, broadly speaking, hypertrophy can occur across a wide range of reps. In particular, it seems that hypertrophy is maximized when lifting loads between 30% and 85% of your one-rep max (1RM), meaning you can achieve muscle growth whether you’re lifting lighter or heavier weights, as long as you’re training near failure.

The key findings from this paper and supporting studies include:

1. Lower Threshold for Hypertrophy:

   • Studies, such as those by Buckner (2020) and Lasevicius (2018), found that using weights as low as 30% of 1RM can stimulate hypertrophy, provided you lift close to failure.
   • In one study, Buckner and colleagues compared training at 70% of 1RM versus 15% of 1RM using blood flow restriction. Results showed that 70% of 1RM resulted in more hypertrophy, indicating that while lighter loads (below 30%) can still build muscle, they may be less effective.

2. Upper Threshold for Hypertrophy:

   • On the heavier end, Schoenfeld et al. found that hypertrophy can occur with reps as low as five. However, sets with reps below five may shift the focus more toward strength development rather than hypertrophy.
   • For example, one study compared three sets of 8-12 reps with three sets of 2-4 reps and found better hypertrophy in the higher rep range group. Additionally, lower rep sets (1-5 reps) may induce strength gains, but hypertrophy was still observed in some cases.

3. Middle Ground for Hypertrophy:

   • Research suggests the most efficient rep range for hypertrophy might lie between 5 and 50 reps. The traditional 6-12 rep range isn't "wrong," but it's more of a guideline than a hard rule.
   • A 2019 meta-analysis by Schoenfeld found that lifting at 30% of your 1RM (which corresponds to about 50 reps per set) can result in similar hypertrophy compared to lifting at 80% of your 1RM (around 6-8 reps), as long as both are performed to failure.

The Importance of Training to Failure

Training to failure—or very close to it—appears to be one of the most critical factors for hypertrophy, regardless of rep range. When you push your muscles to their limit, you maximize muscle fiber recruitment, which in turn stimulates growth. As reps increase, it becomes harder to gauge how close you are to failure, which is why higher rep ranges can be challenging to manage effectively.

For instance, studies show that most people can accurately judge how close they are to failure when lifting heavier weights (lower reps), but tend to overestimate how close they are to failure when performing higher-rep sets. This can lead to suboptimal training if you're not pushing yourself hard enough.

Why Variety Matters for Muscle Growth

While you can build muscle in a wide range of rep schemes, there is evidence suggesting that incorporating a variety of rep ranges in your training program may offer slight advantages in terms of muscle growth.

Zach Robinson’s meta-analysis highlights that mixing different rep ranges could potentially yield more overall muscle mass than sticking to just one range. This variety ensures you're working all muscle fibers—both fast-twitch (Type II) and slow-twitch (Type I)—for maximum hypertrophy.

Incorporating low-rep, moderate-rep, and high-rep work into your routine may be more beneficial than exclusively focusing on a single rep range. This mixed approach could lead to more balanced growth across different muscle fibers and regions.

Specific Scenarios: When High and Low Reps Shine

Certain exercises and circumstances may be better suited for higher or lower reps, depending on the muscle group or goal.

1. Use Higher Reps (15-50):

   • For isolation exercises: Movements like bicep curls, leg extensions, and lateral raises may feel more comfortable in higher rep ranges, helping you achieve a greater "pump."
   • When dealing with joint pain: Lifting lighter weights with higher reps can help alleviate strain on joints while still stimulating muscle growth.
   • When equipment is limited: If you're traveling or only have resistance bands, high-rep bodyweight exercises (e.g., 30-50 reps of push-ups) may be necessary to reach muscular fatigue.

2. Use Lower Reps (5-12):

   • For compound lifts: Squats, deadlifts, and bench presses tend to feel more efficient in the lower rep ranges (e.g., 5-12 reps), especially when the goal is to balance strength with hypertrophy.
   • Powerbuilding goals: If you're trying to build both strength and muscle mass, sets of 3-8 reps on compound lifts can help achieve both goals simultaneously.

The Bottom Line: Hypertrophy is Flexible

The traditional 8-12 rep hypertrophy range is not the only path to muscle growth. Research shows that hypertrophy can occur across a much wider range, from as low as 5 reps to as high as 50 reps, provided you train close to failure. Incorporating a variety of rep ranges into your workout routine not only helps target different muscle fibers but also keeps training interesting and enjoyable.

In summary:

• Aim for 5-50 reps per set for hypertrophy, depending on the exercise and preference.
• Train close to failure to maximize muscle fiber recruitment and growth.
• Use a variety of rep ranges to ensure you're hitting all muscle fibers and prevent training monotony.

While science continues to evolve, these guidelines offer a practical and evidence-backed approach to maximizing muscle growth. Whether you're a beginner or a seasoned lifter, understanding that hypertrophy is flexible allows you to tailor your training to your preferences while still seeing gains.