We have two categories of exercises under weight training, which are isolation and compound exercises. Isolation exercises, which involves one joint or single muscle during movements. Examples of isolation are biceps curls (only elbow joint is involved), knee extensions (only knee joint is involved), chest flyes etc.
Whereas the compound exercises are those which involves the use of more than one joint or muscle group. Example of compound exercises are: squat (knee, hip and ankle joints are involved), bench press (shoulder and elbow joints are involved) etc.
Which one compound or isolation?
As with compound exercises one will be working on more than one muscle group therefore it aids in improving person’s overall fitness and increase in strength throughout the entire body. Also, if you see our day to day activities, whether lifting your bag, to open door or could be anything.
All of these activities and in fact most of our activities of daily living are compound movements. So if you see in real life our body works in conjunction with the rest of the body and therefore we should train our body in that way.
Isolation exercises allows to focus on just one area and target the muscles that aren’t being worked well enough in the usual workouts. Although small muscle group such as bicep brachii is used as a synergist or helping muscle in most of the workout, but if you want to specifically train that muscle we normally perform isolation exercises only.
Isolation exercises has its own importance. If you have a muscular imbalance then with isolation exercises you can specifically work on your weak area. Also, isolation exercises are excellent for physical therapy and rehabilitation program.
Isolation exercises are an important element of pre-exhaustion training technique, where we isolate the desired muscle group at the beginning of the workout and then followed by compound exercises.
So, include both compound and isolation exercises in your workout ,but the majority of our exercises should be compound as they are functional.