Compound exercises are multi-joint movements that work several muscles or muscle groups at one time. Some classic examples of compound exercises include the squat, deadlift and military press. Whether you're training for functionality, sport performance and even bodybuilding - big compound exercises are essential in anyone’s training program.
During compound exercises more muscle groups are utilized and as such, a greater % of muscle fibers are stimulated making these movements incredibly efficient. For example a deadlift will recruit muscle fibers from practically every muscle in your entire body - the pull phase places a great load on your trapezius and erector spinae muscles, as the bar moves upwards the emphasis switches to your hamstring, glutes and of course as with any exercise holding a bar, your forearms and all the small muscles involved in grip strength are heavily activated. This ends in burning more calories, giving the body a strong stimulus to maintain or build muscle and strength, and to gain the most amount of added muscle tissue in the least amount of time.
Isolated exercises simply will not yield the same bang for buck when compared to compound exercises so for time conscious gym goers they're the most efficient use of time. There is of course a place for isolated exercises, but compound exercises really help bring all your hard work together to build a more well-rounded unit - think of isolation as the bricks and compound movements as your end product. Isolation exercises are perfect for bringing up weaker muscle groups, or to shift focus onto muscles that you particularly want to improve. If you want to switch focus to your arms for example, use the big compound movements to work grip strength and co-ordination and then use isolation to localize load to particular muscle or muscle group.
Now lets talk hormones. The large number of muscles recruited drastically increases the release of anabolic hormones into the body’s circulation, such as testosterone and growth hormone to name but two. These two hormones are responsible for the development and growth of muscle and can work with a sound diet and good recovery to influence body fat reduction. Isolation exercises alone in contrast will not have the same effect on the amount release of these valuable hormones.
If we look at the application of gym work to sports this again is an area where you really cannot go without including compound movements. How many sports can you think of that use just one joint to perform? So what kind of carry over do you think isolating a joint will have to a sport? If you're injured and your manual therapist wants to condition specific muscles then of course there is carry over - but generally speaking, if we are taking about increasing performance, isolation exercises will not make any difference to how you perform in your chosen event.
The only caution when learning compound movements is that there is an element of ego attached to throwing a lot of weight on the bar, as these movements are the most greatly loaded exercises you can do. This is a sure fire way to get injured so before attempting to test your limits, take the time to learn proper technique from a qualified individual or trainer first and not just rely on a quick how to video on the Internet. Once proper form is established you are far better equipped to deal with the increasing loads safely and will significantly reduce the risk of injury.
Finally and perhaps most importantly there are no better exercises to load the axial skeleton than compound lifting, especially squats and dead lifts. The axial skeleton comprises of the sacrum, vertebra and the cranium and it is held together by a number of strong, connective tissues such as ligaments, fascia and the intervertebral discs. These structures absolutely thrive on being loaded because this is how they receive their nutrition - they don't have vast arterial capillaries to rely on like the muscular system and as such depend on movement and compression for their health. But why is this going to help you in the gym? Well, if you can understand the concept of intra-abdominal pressure you're almost there, this is a mechanism by which your body synergistically combines the two forces of:
1) the force of internal pressure caused by filling your lungs and holding your breath - pushing out.
2) the bracing force of your deep abdominal wall musculature that joins to your thoracolumbar fascia - pulling in.
These two forces load your abdominal musculature greater than any 5 minutes of planking or tens of thousands of ab crunches! There is a time and place for these exercises but progression isn't always about doing more of a given action, it's about breaking down how the body works and what will realistically be needed to instigate change. So to answer our original question - this is relevant to our body because not only does it provide a strong connection between your upper and lower extremities but it's also vital for the health of your spine.
Take home
- Compound exercises stimulate more muscle fibres.
- Increased calorie expenditure leading to better fat metabolism.
- Increased levels of your own natural anabolic hormones
- Better sport and real life carry over
- Improved global strength and co-ordination between muscle groups
- The more muscles being worked, the more amount of weight lifted. This leads to bigger improvement in strength
- Hit more muscle groups in one exercise so you don’t have to train for so long on days when you're limited on time.