Single joint exercises aka isolation exercise are those where one muscle group is engaged. For example biceps curl, preacher curl, leg extension, leg curl, wrist curl, front raise, lateral raise are single joint exercises. Technically speaking there is no typical single joint workout. Even if the above workouts mainly focus on one particular muscle, the nearby muscle plays a small role and works as ancillary muscle.
Multi joint exercises comprise complex movements engaging more than one muscle group simultaneously. Examples of multi joint workouts are Squat, lunge, pull up, chin up, push up, bench press, and shoulder press.
Why multi joint workouts are better?
Multi joint exercises always play a better role compared to any single joint exercise. Below are the main factors that should be enough to change your focus towards performing multi joints workouts than any single joint or so called isolation workout.
- Burn more calories: Multi joint exercises use a large group of muscles and comprise complex muscle movements unlike isolation exercises. Hence by working on more than one muscle group we burn substantially more calories than doing any other isolation or single joint exercise
- Best weapon to fight fat: It is a proven fact that an intense training session comprising mostly multi joint exercises works best increasing the RMR substantially for next 1/2 days thus helping in fat-burn or weight-loss program. Hence performing mostly multi-joint workouts 3 to 4 times per week we can keep our metabolism high 24x7. Unlike multi joint exercises single joint, or so called isolation workouts, are not effective enough to keep the RMR high for such a long time after a workout session.
- Build full functinal body: People going for isolation exercises tend to exercise for their favorite body part only. I encountered people only doing workouts for chest or biceps. This practice leads to unbalanced body which is not functional at all and actually prone to injuries. Whereas in multi joint exercises, more than one muscle groups engage simultaneously and work in a harmony increasing strength and co-ordination between different body parts. Thus multi-joint workouts are best for building a full functional fit body.
So I would strongly suggest practicing more of multi-joint workouts complemented with single joint exercises (if multi joint exercise is not possible every time).