The fitness world is rife with debates, and one that has been ongoing for years is the comparison between single joint exercise and multi joint exercises, particularly concerning their effects on muscle damage and recovery time. Many coaches and fitness magazines have long claimed that exercises like squats and deadlifts take longer to recover from than leg extensions and cable isolation exercises. But how much truth is there to this statement?
The general belief is that multi joint exercises, which engage multiple muscle groups and joints simultaneously (e.g., squats, deadlifts), result in greater muscle damage and, therefore, require a longer recovery period. On the other hand, single-joint exercises, which isolate specific muscles (e.g., bicep curls, leg extensions), are thought to cause less muscle damage and allow for quicker recovery. This article delves into the research to comprehensively understand the effects of muscle damage on isolation and multi joint movements.
Key Findings: Multi-Joint Exercise and Muscle Damage
- Researchers investigated the time course of muscle recovery of the quadriceps after single (i.e., leg extensions) – and multi joint exercises (i.e., leg press). The researchers conducted various tests and measurements before and after exercise protocols to assess the impact on muscle strength, power, and swelling.
- Peak torque (i.e., the maximum force generated by the muscles during a specific movement) was fully recovered 24 hours after the knee extension exercise. In contrast, it returned to baseline values 48 hours after the leg press exercise. However, there was only a 1.4% difference at 24 hours post-training in the decrease in peak torque between conditions (leg press: -6.1%; leg extension: -4.7%;) This means that there were very small differences between the two and likely not meaningful.
- The leg press exercise resulted in greater rectus femoris (i.e., a muscle located in the quadriceps group of muscles in the front of the thigh) muscle damage and longer recovery compared to the knee extension exercise. However. the knee extension exercise resulted in greater vastus lateralis (i.e., a muscle on the side of the thigh) muscle damage compared to the leg press exercise.
- The study found that knee extension and leg press exercises temporarily decreased peak torque and jump performance and increased muscle inflammation and swelling. However, the two exercises had no significant differences in the ability to perform tasks related to daily life or sports (functional performance).
What is a Single Joint Exercise
A single joint exercise like bicep curls and tricep extensions are designed to isolate specific muscles. Unlike multi joint exercises that engage multiple muscle groups simultaneously, a single joint exercise involve movement at only one joint. This makes them suitable for targeting specific muscle groups or imbalances.
While a single joint exercise primarily focus on the targeted muscle, they also play a secondary role in multi-joint movements by acting as stabilizers or providing assistance to nearby muscles. By performing exercises that involve a single joint, like a leg curl or wrist curl, you can effectively work on strengthening that specific area of your body. However, it’s important to exercise caution and ensure proper form to avoid injury to the joint or surrounding muscles.
In accordance with anatomy and biomechanics, a single joint exercise can be performed using free weights or machines, and adjusting the load (heavier weights, more reps) can be a good idea if you’re looking to challenge the targeted muscle further. Ultimately, incorporating single joint exercises into your fitness routine can make a lot of sense, especially when striving to target specific muscle groups or address muscle imbalances.
Defining Multi-Joint Exercises
Multi-joint exercises, also known as compound exercises, involve the activation of multiple muscles and joints. These exercises require coordination and stability, making them an effective way to train your body as a whole. Examples include squats and bench presses, both of which involve movements in more than one joint.
By mimicking natural movements, multi-joint exercises target the primary muscle groups and nearby and ancillary muscles. This comprehensive engagement of muscles leads to increased muscle activation and a higher calorie burn during workouts. Additionally, multi-joint exercises allow for the application of heavier weights, which can stimulate muscle growth and enhance strength development.
In accordance with the principles of anatomy and biomechanics, incorporating multi-joint exercises into your fitness routine makes a lot of sense and is a good idea for overall strength and muscle development.
Single vs Multi Joint Exercises for Hypertrophy
Several studies have compared the effects of single and multi-joint exercises on muscle hypertrophy. As written previously on Evidence Based Muscle, you need both for optimal muscle hypertrophy.
A study by Paoli et al. directly compares single-joint and multi-joint exercises. The study found that both exercise types led to decreased body fat and increased muscle strength. However, cardiorespiratory fitness and maximal strength improvements were higher in the multi-joint group. (Paoli et al., 2017)
Similarly, another study reported that multi-joint exercises were more effective than single-joint exercises in increasing maximal strength, muscle activation, and metabolic stress. (Stien et al., 2020) However, others have reported no difference in bicep gains and hypertrophy between multi-joint and single-joint exercise training, suggesting that muscle damage caused by both types of exercises may be similar. (Gentil et al., 2015)
Delving into the Impact of Single-Joint and Multi-Joint Exercises on Muscle Damage and Recovery
Several studies have investigated muscle damage and recovery differences between single and multi-joint exercises. A 2015 study on highly resistance-trained men found that multi-joint exercises resulted in greater muscle damage and longer recovery time than single-joint exercises.(Soares et al., 2015)
A study on resistance-trained men compared the recovery of indirect markers of muscle damage between single-joint and multi-joint exercises. They found that multi-joint exercises resulted in greater muscle damage and longer recovery time than single-joint exercises. (Camargo et al., 2020)
Factors Influencing Muscle Damage
Muscle damage and subsequent recovery are influenced by a multitude of factors, including:
- Proximity to failure
- The total volume of exercise
- The specific exercise performed
- Lifter’s training experience
Understanding these variables is crucial for athletes and fitness enthusiasts to optimize their training regimens.
What Does Current Research Say About Muscle Damage in Single vs Multi-Joint Exercises?
A recent study by Dourado et al. investigated the time course of muscle damage, jump performance, and muscle thickness after knee extension leg press exercises. (Dourado et al., 2023)
The researchers took 14 young men who were not trained athletes and had them do two types of lower-body exercises: knee extensions (a single-joint exercise) and leg presses (a multi-joint exercise). They measured three things:
- Peak Torque (PT): This is a measure of how much force the muscles can produce. Think of it as the “power” of your muscle.
- Muscle Swelling: This helps to understand if the muscle is swollen or inflamed after exercise. It’s a marker of muscle damage.
- Jump Performance: This is to see how well the muscles function in a real-world scenario.
They measured these factors before and after the exercise: immediately, 24 hours, 48 hours, 72 hours, and 96 hours later.
What Did They Find?
Muscle Power (PT): They found that the muscle power dropped right after both exercises but came back to normal faster after the single-joint exercise (24 hours) compared to the multi-joint exercise (48 hours) However, there was only a 1.4% difference at 24 hours post-training in the decrease in peak torque between conditions (leg press: -6.1%; leg extension: -4.7%;) This means that there were very small differences between the two and likely not meaningful. Both groups returned to normal by 48 hours.
Muscle Swelling: Both exercises caused the muscles to swell (which is normal and part of the recovery process). However, the swelling went down faster after the single-joint exercise.
Jump Performance: The ability to jump well (which you can think of as a real-world test of muscle function) also returned to normal faster after the single-joint exercise.
Most athletes combine single and multi-joint exercises in their training programs. The study suggests that the type of exercise, the volume, and how close one is to training failure are more critical factors affecting recovery than whether the exercise is single or multi-joint.
Implications of the Research
Most athletes employ a combination of single and multi-joint exercises in their training programs. The study suggests that the type of exercise, the volume, and how close one is to training failure are more critical factors affecting recovery than whether the exercise is single or multi-joint. The study emphasizes that athletes should not feel fatigued constantly throughout a workout program. Persistent fatigue may be an indicator that more rest is needed between training sessions, regardless of the type of exercises performed.
When designing your training program, it’s important to incorporate a combination of both single and multi-joint exercises. This approach allows for balanced muscle development and ensures that you are targeting different muscle groups effectively. To minimize the risk of injury during exercise, focus on proper form and technique. Allow for adequate recovery between workouts to optimize muscle repair and minimize the risk of excessive muscle damage. Customizing your exercise selection based on your individual goals, preferences, and the specific muscle groups you want to target will ensure that you are optimizing your training program.
Camargo, J. B. B. d., Braz, T. V., Batista, D. R., Germano, M. D., Brigatto, F. A., & Lopes, C. R. (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. https://doi.org/10.1519/jsc.0000000000003811
Dourado, M. A. A., Vieira, D. C. L., Boullosa, D., & Bottaro, M. (2023). Different time course recovery of muscle edema within the quadriceps femoris and functional performance after single- vs. multi-joint exercises. Biol Sport, 40(3), 767-774. https://doi.org/10.5114/biolsport.2023.119984
Gentil, P., Soares, S., & Bottaro, M. (2015). Single vs. Multi-Joint Resistance Exercises: Effects on Muscle Strength and Hypertrophy. Asian J Sports Med, 6(2), e24057. https://doi.org/10.5812/asjsm.24057
Paoli, A., Gentil, P., Moro, T., Marcolin, G., & Bianco, A. (2017). Resistance Training with Single vs. Multi-joint Exercises at Equal Total Load Volume: Effects on Body Composition, Cardiorespiratory Fitness, and Muscle Strength. Frontiers in Physiology, 8, 1105-1105. https://doi.org/10.3389/fphys.2017.01105
Soares, S., Ferreira-Junior, J. B., Pereira, M. C., Cleto, V. A., Castanheira, R., Cadore, E. L., Brown, L. E., Gentil, P., Bemben, M. G., & Bottaro, M. (2015). Dissociated Time Course of Muscle Damage Recovery Between Single- And Multi-Joint Exercises in Highly Resistance-Trained Men. The Journal of Strength and Conditioning Research. https://doi.org/10.1519/jsc.0000000000000899
Stien, N., Pedersen, H. H., Ravnøy, A. H., Andersen, V., & Saeterbakken, A. H. (2020). Training Specificity Performing Single-Joint vs. Multi-Joint Resistance Exercises Among Physically Active Females: A Randomized Controlled Trial. PLoS One. https://doi.org/10.1371/journal.pone.0233540
The present article aims to explore the best way to gain muscle mass and achieve weight loss through strength training. We focus on multi-joint lifts and single-joint movements.
Multi Joint Lifts
Multi joint exercise, like the squat (exercise), engages multiple parts of your body, including lower limbs and hip extensors. These lifts are excellent for calorie burning and adaptations in muscle mass. They are a staple in powerlifting and bodybuilding.
Benefits of Multi Joint Exercises such as Squats and Deadlifts:
- Greater calories burned, aiding in fat loss.
- The use of a barbell allows for heavier weights, contributing to strength training.
Single-joint movements, like biceps curls, focus on a single muscle group. They are often performed with a dumbbell and target specific muscles like the hamstrings or upper body.
- Isolation of elbow joint in biceps curls.
- Targeted muscle mass gain in specific areas.
- Easier to perform, requiring less cm of movement.
Both multi-joint lifts and single-joint movements have their place in strength training. Compound lifts are generally better for overall muscle mass and calorie burning, while single-joint movements are excellent for targeting specific parts of your body. Choose based on your strength training and weight loss goals.
What are multi-joint exercises and why are they important?
Multi joint exercises are exercises that involve the movement of multiple joints and muscle groups. They are important because they allow for more efficient and effective workouts, as they engage multiple muscles at once. This leads to greater strength gains, improved coordination, and increased calorie burn.