A 5×5 program can build muscle, but it’s not the most efficient way to train if hypertrophy is your primary goal. The research is clear that muscle growth can occur across a wide spectrum of rep ranges, from heavy sets of 3 to lighter sets of 25+, as long as sets are sufficiently challenging. Where 5×5 falls short isn’t in the rep range itself but in total weekly volume and muscle group coverage.
What the Research Says About Rep Ranges and Growth
The old idea that you need 8 to 12 reps to build muscle has been largely overturned. A major meta-analysis comparing high-load training (above 60% of your max) to low-load training found virtually no difference in muscle growth between conditions, with a trivial effect size of 0.03. The key finding: muscle hypertrophy can be equally achieved across a spectrum of loading ranges, while maximal strength benefits specifically require heavy loads.
Several studies back this up directly for the 5-rep range. When researchers compared a powerlifting-style protocol (7 sets of about 3 reps) to a bodybuilding-style protocol (3 sets of about 10 reps) with equal total volume, both groups saw similar increases in biceps thickness after 8 weeks. Another study comparing 2 to 6 reps against 8 to 12 reps found similar changes in chest and quad thickness.
That said, not every study shows a dead heat. One study found greater thigh muscle growth in a group doing 3 sets of 8 to 12 reps compared to 2 to 4 reps. The difference likely comes down to a practical problem: when you train very heavy, each set generates more fatigue relative to the growth stimulus it provides. You can only do so many heavy sets before your joints, nervous system, and recovery capacity tap out. Moderate rep ranges let you accumulate more growth-producing volume before hitting that wall.
The Real Problem: Weekly Volume
This is where standard 5×5 programs struggle most. A systematic review on training volume and hypertrophy found that 12 to 20 weekly sets per muscle group is the optimal range for trained lifters looking to maximize growth. Anything under 12 weekly sets was classified as “low volume,” and the evidence strongly favors at least 9 weekly sets per muscle group as a minimum threshold.
A classic 5×5 program like StrongLifts has you squatting 5 sets three times per week (15 weekly sets for quads, which is solid) but only bench pressing or overhead pressing 5 sets on alternating days. That leaves your chest and shoulders at roughly 5 to 7.5 weekly sets, well below the 12-set minimum for optimal growth. Your back, biceps, and triceps are in a similar position. The squat volume is adequate; almost everything else is underdosed for hypertrophy.
Muscle Groups That Get Left Behind
Standard 5×5 routines are built around compound lifts: squats, bench press, overhead press, barbell rows, and deadlifts. These are excellent exercises, but they don’t distribute stimulus evenly across your body. Your side delts get almost no direct work. Your biceps are only trained indirectly through rows. Your hamstrings get some stimulus from deadlifts, but not nearly as much as a dedicated leg curl or Romanian deadlift would provide. Even the creator of StrongLifts 5×5 acknowledges that people look at the program and worry their arms will stay small, because there are no curls or direct arm work.
If you care about balanced, visible muscle development, a compound-only 5×5 program will leave gaps. The muscles that respond best to isolation work (biceps, triceps, lateral delts, rear delts, calves) simply don’t get enough stimulus from five sets of barbell rows and bench press.
What 5×5 Does Well
Heavy compound sets in the 5-rep range produce high levels of mechanical tension, one of the primary drivers of muscle growth. This type of training is exceptionally good at building strength, which has a compounding effect on hypertrophy over time. The stronger you are, the more weight you can eventually use in higher-rep work, which means a greater growth stimulus down the road.
For beginners, 5×5 programs are particularly effective because any challenging resistance training builds muscle when you’re new to lifting. The simplicity of only needing to learn a handful of movements, combined with a clear progression model (add weight every session), makes it a reliable starting point. Beginners also recover faster and don’t need the same volume thresholds that trained lifters do. If you’ve been lifting for less than six months, a 5×5 program will build meaningful muscle.
How to Make 5×5 Better for Growth
If you like the structure of 5×5 training but want more muscle growth, the fix is straightforward: keep the heavy compound work and add volume on top of it.
- Add accessory exercises after your main lifts. Two to three movements in the 8 to 15 rep range targeting muscles the compounds miss. Curls, lateral raises, triceps extensions, face pulls, and leg curls are the most common additions.
- Increase weekly frequency for lagging groups. If your chest only gets 5 sets of bench press per week, adding 3 sets of dumbbell presses or flyes on another day brings you closer to that 12-set weekly minimum.
- Push your sets closer to failure. A set of 5 with 3 reps still in the tank produces far less growth stimulus than a set of 5 where you could only manage one more rep. Proximity to failure matters at least as much as rep range.
- Use the 5×5 as a strength block, not a permanent program. Spend 6 to 8 weeks building strength with heavy compounds, then transition to a higher-volume phase with more moderate loads and more exercises. This periodized approach gives you the benefits of both training styles.
5×5 vs. Higher-Rep Programs for Hypertrophy
A program built around 3 to 4 sets of 8 to 12 reps across more exercises will generally produce more muscle growth than a straight 5×5 program, not because the rep range is magic, but because it allows you to accumulate more total volume with less joint stress and systemic fatigue. Five heavy sets of squats at 85% of your max takes a serious toll on your body. Five heavy sets of bench press afterward takes even more. By the time you finish a full 5×5 workout, you may not have the capacity to do meaningful accessory work.
Moderate rep ranges are simply more volume-efficient. You get a strong growth stimulus per set without the recovery cost that very heavy loads demand. This is why bodybuilders have historically trained with moderate loads and shorter rest periods, while powerlifters use heavy loads with long rest periods. Both groups build muscle, but the bodybuilder’s approach is optimized for it.
The bottom line: 5×5 builds muscle, especially in beginners and in the muscle groups directly targeted by compound lifts. But if hypertrophy is your priority, you’ll get better results by either supplementing a 5×5 base with higher-rep accessory work or switching to a program designed with volume and muscle coverage in mind from the start.