There have been many conversations on the use of isolation and compound exercises to build muscle. By definition, compound exercises engage multiple joints and muscle groups in a single workout while isolation exercises only target individual muscle groups. While both exercises used in conjunction will grow muscles faster, in comparison, compound exercises are much more effective than isolation exercises.
For example, while an isolation exercise like bicep curls only works bicep muscles and triceps extensions work triceps, compound exercises like squats and deadlifts work more muscle groups like quads, hamstrings, and glutes. This means that in a single workout, you stand to gain much more since you are exercising multiple muscle groups.
You may already know that compound exercises are more effective because they work more muscle groups, but it is usually a mystery any further reasons behind this. Below are the reasons why using compound lifts will help you build muscles faster.
Compound exercises work several muscle groups in a single workout – This is the most widely known reason. It is also very true. As we have already attested, compound exercises are better at working several muscles in a single workout and providing comprehensive benefits for many muscle groups. However, even compound exercises target particular muscle groups, just that they get help from other muscle groups surrounding the major muscle. For example, for a squat, the primary muscle group targeted is the quad, surrounding muscles like the glutes, adductors, hamstrings, erector spinae, and rectus abdominis also get a workout. This means that the quads and all other muscles engaged during the workout will build up over time.
Compound exercises increase HGH (Human Growth Hormone) levels – When working out, muscles stimulate the secretion of the Human Growth Hormone (HGH) by the anterior lobe of the pituitary gland. As the name suggests, HGH is responsible for stimulating growth in a person’s body and is, therefore, essential for muscle growth. It stimulates protein synthesis and breakdown on fat as an energy source for tissue growth. Therefore, the stimulation of the pituitary gland when doing a compound exercise is higher than the resulting stimulation when doing an isolation exercise due to the number of muscles involved. Consequently, more HGH means muscles will grow bigger, faster.
Compound exercises increase nerve activity and use of muscle fiber – Working many muscle groups usually works many muscle fibers and results in a higher level of nerve activity. This means that the nerves are sending strong signals to muscles to recruit even more muscle fibers which result in muscle growth because the nerves control development and maintenance of muscles. Therefore, when you force nerves to work a lot of muscles fibers at once, you are giving room for a lot of growth and strength.
Compound exercises are more exhausting – Since many muscles groups are engaged in compound exercises, several muscle groups are usually exhausted by the end of the workout. Because muscles usually respond to exhaustion by growing so that they can manage the load better, simultaneous growth of several muscle growths usually results in the size and strength gains desired in a shorter time. It would take several isolation workouts to achieve the same result.