This is an apt description, as your goal is to gradually increase the amount of weight lifted in each exercise. Contrary to what many believe, muscles do not grow during training. Think of exercise as a type of message. By working out you are ordering your muscles to get bigger and stronger. With time you have to send stronger messages (heavier weight) to get the same effect.
Adaptation is defined as a change in response to a stimulus. Let’s see how this definition applies to bodybuilding. When you perform an intense set of curls, after a given number of reps the biceps become fatigued. Over the next couple of days the body repairs the damage.(This term does not imply that the muscle itself has been injured, only that some muscle tissue has been broken down.) Repair involves the use of building blocks called amino acids (more on these in the nutrition chapter). The body combines the amino acids into protein which is then integrated into muscle tissue.
An interesting fact about the recuperation process is that the body doesn’t repair the muscle as it was. Instead it goes a step further, making the muscle slightly larger and stronger. In effect, your body is saying: “Whoa, that was a great deal of stress. I need to make that muscle stronger so next time it can handle that stress better.” Once the extra muscle tissue has been built, you can see that your body will handle that weight quite well. To keep the muscle growing, the amount of weight lifted must be gradually (gradually!) increased.
That way, your body is always trying to deal with increased loads by adding a little more muscle tissue. Most muscle growth is the result of what’s called hypertrophy – the increase in diameter of existing muscle cells. In addition, the muscles’ blood supply and number of mitochondria (energy-producing organelles) is increased. Of course the opposite can also occur. If a muscle is not regularly exercised, or if there has been some sort of nerve damage, it begins to shrink. This process is called muscular atrophy.
A good example of atrophy can be seen in astronauts who spend long periods of time in orbit. The reduced gravity means their muscles don’t have to work as hard and they lose muscle mass. At one time it was believed that hypertrophy was the only mechanism by which muscles grew, but the evidence is mounting that intense forms of exercise – particularly weight training– can cause individual muscle fibers to split. Each part of a split cell will become a cell on its own, and increase to normal cellular size. This is welcome news for those who weren’t blessed genetically with a larger number of muscle fibers to begin with. As Jeff Goldblum said in the movie Jurassic Park, “Nature always finds a way.”
Muscles are not attached directly to bones or other muscles. They are connected by a tough cord of connective tissue called a tendon. A tendon may connect a muscle to another muscle, or a muscle to a bone. The thickest tendon in the human body is the Achilles’ tendon. It attaches the calf muscle to the heel bone. From a bodybuilding perspective, the biceps tendon, which connects the biceps to the radius bone of the forearm, is probably the most familiar. Tendons add length and thickness to muscles and are especially important in reducing muscle strain.
Bones are held together by fibrous connective tissue called ligaments. Varying in shape and even strength, depending on their location and function, most ligaments are considered inelastic, yet they are pliable enough to permit movement. Ligaments tend to tear rather than stretch, but because of their strength they can withstand a great amount of stress. When they do tear, the condition is marked by intense pain and swelling. Surgery is often needed to correct the problem.
Cartilage is a specialized type of connective tissue and can be called the shock absorbers of the body. Its main function is to prevent bones from rubbing against one another within a joint. With time, disease or injury, cartilage tissue may become damaged, resulting in reduced movement and pain. One of the most frequent sports injuries is torn knee cartilage. When this happens the cartilage may become lodged between the upper (femur) and lower (tibia) leg bones, causing the joint to lock.
The patient of 20 years ago could look forward to many months of therapy and pain after surgery. Recent advances in arthroscopic surgery have cut the recovery time in half. Using microscopic tools, surgeons can repair the damaged cartilage and allow movement much sooner, preventing the surrounding muscles from atrophying. As with other sports, the most common bodybuilding injuries concern the knee region. Bouncing at the bottom of the squat does not make for a great set of thighs. Neither does forcefully locking out in the leg extension. These motions both lead to damaged knees. Remember to always perform the movements in a nice, slow and controlled manner.
Bursae and Tendon Sheaths
Two other structures associated with muscles and joints are bursae and tendon sheaths. Bursae are flattened sacs filled with synovial fluid. They are found wherever it is necessary to eliminate the friction that occurs when a muscle or tendon rubs against another muscle, tendon or bone. Bursae also cushion certain muscles and facilitate the movement of muscles over bony surfaces. A modification of bursae is tendon sheaths – long cylindrical sacs filled with synovial fluid that surround long tendons. Tendon sheaths allow tendons to slide easily. They are found in areas where the tendons are under constant movement and friction such as your wrists, fingers and palms.
Robert Kennedy: Encyclopedia of Bodybuilding, TheComplete A-Z Book On Muscle Building. 2008
Nick Evans:Bodybuilding Anatomy. 2012
Arnold Schwarzenegger: The New Encyclopedia of Modern Bodybuilding, 2013