Key Takeaways
- For many years, the idea of single joint vs multi joint hypertrophy wasn’t even a topic—people believed compounds were all you needed for muscle growth.
- Both multi-joint and single-joint exercises hit muscles differently, and skipping one means missing out on growth.
- This new study on single joint vs multi joint hypertrophy shows that certain lifts target specific parts of a muscle, proving that variety is essential.
- The best way to grow? Blend compound moves with isolation work for full, balanced development.
Single Joint vs Multi Joint Hypertrophy and the New Science
For decades, the muscle-building gospel was simple: stick to the big lifts. Squats, deadlifts, and bench presses were the holy trinity. If you wanted size, you loaded up heavy and lifted big. Single-joint exercises like leg extensions or curls? They were often dismissed as “extras”—maybe good for a pump but not serious growth.
That old-school advice isn’t holding up anymore. A brand-new study, Exercise Selection Differentially Influences Lower Body Regional Muscle Development by Burke et al. (2024), published in the Journal of Science in Sport and Exercise, flips that belief on its head. The research makes a strong case that if you want complete growth, you can’t just hammer compounds. You’ve got to bring in isolation work too.
Why does this matter? Because muscles aren’t one big slab of tissue. They’re made up of different regions that respond differently depending on the exercise. If you want to look balanced—and not like you’re missing something—you need more variety than just sticking to your “big three.”
Review of the Literature: Compound vs Isolation Muscle Growth Study
The fight between single-joint (isolation) and multi-joint (compound) exercises has been around as long as bodybuilding itself. Multi-joint lifts are often the favorites, and for good reason. Think about squats or bench presses. They hit multiple muscles at once, let you load heavy, and carry over to athletic movements. They’re efficient and effective, and they build serious strength (Iversen et al., 2021; Gentil et al., 2015; Rosa et al., 2022).
But isolation lifts deserve more credit than they usually get. They let you hone in on one muscle, which is gold if you’ve got weak points. For example, a leg extension is all about the quadriceps—no glutes or hamstrings jumping in to help. This kind of focus makes isolation moves a powerful tool when you’re trying to balance out your physique (Gentil et al., 2015; Rosa et al., 2022).
Research hasn’t been clear-cut. Krieger (2010) found that, set for set, multi-joint training drives hypertrophy, but when total volume is matched, single-joint work can deliver similar results. Stien et al. (2020) highlighted how exercise selection changes activation patterns. Nunes et al. (2020) and Camargo et al. (2020) pointed out that recovery looks different between isolation and compound lifts. The message is clear: both have unique strengths, and leaning too heavily on just one type leaves results on the table.
Results of the Study: Which Builds More Muscle, Leg Extension or Leg Presses?
Burke and his team (2024) put this to the test. They took 30 resistance-trained men and women and had them train one leg with certain exercises and the other leg with different ones. This clever design meant each person was their own control—genetics and lifestyle couldn’t skew the outcome.
Here’s what they found:
- Rectus femoris (the front thigh muscle) grew more from leg extensions than from leg presses.
- Vastus lateralis (the outer thigh muscle) responded better to the leg press.
- Medial gastrocnemius (the inner calf) showed greater growth with straight-leg toe presses, while the soleus leaned slightly toward seated calf raises, though results here weren’t as clear.
So when it comes to which builds more muscle, leg extension or leg presses? The answer is—it depends on the region of the muscle you’re trying to grow. Each exercise brings something different to the table.
Daily Compound vs Isolation Muscle Growth Study Insights
This study underlines something a lot of lifters don’t want to hear: your favorite lifts aren’t enough. Compounds are incredible, no doubt. They build a foundation of strength and muscle like nothing else. But they don’t cover all the bases.
Think about chest training. If you only bench press, sure, your pecs will grow. But you’ll miss out on targeting the lower chest or inner fibers. The same thing happens in your legs and calves. Muscles are layered and segmented. If you want them all to grow, you need to come at them from different angles.
That’s the wake-up call. If you’ve been proud of sticking to just squats and presses, you might be leaving muscle on the table. Variety isn’t just for fun or to kill boredom—it’s essential for full development.
Practical Applications for Single Joint vs Multi Joint Hypertrophy
So how should you use this information in your own training? Here are a few takeaways:
- Blend compounds with isolations. Squats, presses, and deadlifts give you size and strength. Leg extensions, curls, and calf raises fine-tune the details.
- Think in regions, not just muscles. Your quads have different heads, your calves different parts. Don’t treat them as one chunk of tissue.
- Be intentional. If your outer quads are lagging, give more attention to the leg press. If your rectus femoris looks flat, add leg extensions.
- Balance aesthetics with performance. Compounds build your base. Isolations carve out balance and symmetry.
Conclusion
The idea that compounds alone are enough to maximize growth doesn’t stack up anymore. Research on single joint vs multi joint hypertrophy makes it clear: you need both. Multi-joint and single-joint exercises complement each other, filling in the gaps the other leaves behind.
If you want the biggest, most balanced gains, don’t fall for the either-or trap. Use both. Build size and power with compounds, then polish your physique with isolations. Muscles are complex, and they respond best to a complex approach.
FAQ:
What is the difference between single joint vs multi joint hypertrophy?
Single-joint exercises target one muscle directly, while multi-joint exercises hit multiple muscles at once. Both can cause hypertrophy, but the growth tends to occur in different regions of the muscle.
Which builds more muscle, leg extension or leg presses?
Neither is strictly better. Leg extensions grow the rectus femoris more, while leg presses emphasize the vastus lateralis. For balanced growth, you need both.
Should I do daily compound vs isolation muscle growth study workouts?
Doing compounds and isolations daily isn’t necessary. Instead, balance your weekly training with a mix of compound lifts for strength and isolation exercises for detail and symmetry.
Why is variety important for single joint vs multi joint hypertrophy?
Variety ensures all regions of a muscle are trained. Compounds hit overall mass and strength, while isolations fill in the gaps for complete development.
References
Burke, R., Piñero, A., Mohan, A. E., Hermann, T., Sapuppo, M., Augustin, F., Coleman, M., Androulakis Korakakis, P., Wolf, M., Swinton, P. A., & Schoenfeld, B. J. (2024). Exercise selection differentially influences lower body regional muscle development. Journal of Science in Sport and Exercise. https://doi.org/10.1007/s42978-024-00299-4
Camargo, J., Braz, T., Batista, D., Germano, M., Brigatto, F., & Lopes, C. (2020). Dissociated time course of indirect markers of muscle damage recovery between single-joint and multi-joint exercises in resistance-trained men. The Journal of Strength and Conditioning Research, 36(8), 2089-2093. https://doi.org/10.1519/jsc.0000000000003811
Gentil, P., Soares, S., & Bottaro, M. (2015). Single vs. multi-joint resistance exercises: effects on muscle strength and hypertrophy. Asian Journal of Sports Medicine, 6(1). https://doi.org/10.5812/asjsm.24057
Iversen, V., Norum, M., Schöenfeld, B., & Fimland, M. (2021). No time to lift? designing time-efficient training programs for strength and hypertrophy: a narrative review. Sports Medicine, 51(10), 2079-2095. https://doi.org/10.1007/s40279-021-01490-1
Krieger, J. (2010). Single vs. multiple sets of resistance exercise for muscle hypertrophy: a meta-analysis. The Journal of Strength and Conditioning Research, 24(4), 1150-1159. https://doi.org/10.1519/jsc.0b013e3181d4d436
Nunes, J., Grgić, J., Cunha, P., Ribeiro, A., Schöenfeld, B., Salles, B., … & Cyrino, E. (2020). What influence does resistance exercise order have on muscular strength gains and muscle hypertrophy? a systematic review and meta‐analysis. European Journal of Sport Science, 21(2), 149-157. https://doi.org/10.1080/17461391.2020.1733672
Rosa, A., Vazquez, G., Grgić, J., Balachandran, A., Orazem, J., & Schöenfeld, B. (2022). Hypertrophic effects of single- versus multi-joint exercise of the limb muscles: a systematic review and meta-analysis. Strength and Conditioning. https://doi.org/10.1519/ssc.0000000000000720
Stien, N., Pedersen, H., Ravnøy, A., Andersen, V., & Sæterbakken, A. (2020). Training specificity performing single-joint vs. multi-joint resistance exercises among physically active females: a randomized controlled trial. Plos One, 15(5), e0233540. https://doi.org/10.1371/journal.pone.0233540
