For men who are new to weight training, doing exercises that work multiple muscle groups at once—like squats and push-ups—can build strength and reduce body fat slightly, without needing exercises...
Mechanism
Synthesis from 1 study
When untrained men lift heavy weights using compound moves like squats and bench presses, their muscles are pulled hard and work hard, which makes them stronger and helps burn a little fat — adding isolated arm exercises doesn’t make them any stronger or leaner, as shown in 10.4081/ejtm.2018.7827.
Most probable mechanism
When untrained men do compound exercises like squats and bench presses, the heavy lifting pulls hard on their muscles and makes them burn energy quickly, which tells their bodies to build more muscle strength and burn a little fat — and adding isolated arm exercises doesn’t make them stronger or leaner in any meaningful way, according to 10.4081/ejtm.2018.7827.
Multi-joint exercises such as squats and bench presses generate high levels of mechanical tension across large muscle groups, activating muscle fibers throughout the limbs and trunk, which triggers intracellular signaling pathways that promote muscle protein synthesis and neural adaptation
The metabolic stress from high-volume, multi-joint resistance training increases energy demand and local accumulation of metabolites, which enhances systemic hormonal responses and fat mobilization, contributing to modest reductions in skinfold thickness
Neural adaptations, including increased motor unit recruitment and improved inter-muscle coordination, occur in response to repeated multi-joint loading, leading to significant strength gains without requiring isolated exercises
The absence of additional strength or skinfold thickness improvements in the group performing only multi-joint exercises compared to those adding single-joint exercises indicates that the mechanical and metabolic stimuli from compound movements alone are sufficient to drive these outcomes
Less supported by current evidence, but not ruled out
Adding isolated arm exercises like bicep curls and triceps extensions may cause slightly more arm muscle growth because they target those muscles more directly, but this doesn’t make people stronger or leaner overall, according to 10.4081/ejtm.2018.7827.
Single-joint exercises apply focused mechanical tension to the biceps brachii and triceps brachii, increasing local muscle fiber recruitment beyond what is achieved during multi-joint movements
This focused overload elevates mTOR signaling and protein synthesis specifically in the elbow flexors and extensors, leading to greater regional hypertrophy reflected in increased flexed arm circumference
The increased arm circumference observed in the group performing single-joint exercises does not translate to greater strength or fat loss, indicating this pathway affects only local muscle size, not systemic outcomes
Evidence from Studies
Supporting (1)
Community contributions welcome
Does the addition of single joint exercises to a resistance training program improve changes in performance and anthropometric measures in untrained men?
Contradicting (0)
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