Society has long been fascinated with feats of strength dating all the way back to the BC era – one great example is the legend of Milo of Croton. Milo was a Greek Olympian who was said to have carried a baby calf every day until it grew to full maturity; legend has it as the calf grew into a full size bull, he too grew larger and stronger. Whether this is true or not, since then there have been many great feats of strength achieved and documented.
Fast forward many years Soviet weightlifter Vasily Alekseyev in 1970 was the first man to clean and jerk 500 lbs, he set 80 world records and his career best in the clean and jerk was 564 lbs. The current record in the clean and jerk is roughly 582 lbs, 264 Kg to be exact and is held by Russian weightlifter Aleksey Lovchev. The big question is how did these individuals get so strong, and what does it take for the human body to accomplish these amazing feats of strength?
How Do You Get Stronger… Scientifically?
Quite simply, years of hard work is what makes an individual strong. Scientifically, physiological adaptation is what causes and individual to acquire strength. Early into an exercise program one gets stronger by a phenomenon known as autogenic inhibition. Autogenic inhibition is a result of increased force production due to a decrease in the inhibitory mechanism that causes a muscle to relax.
During the eccentric (lengthening) contraction or in layman’s terms the lowering phase, the golgi tendon organ senses a stretch in the muscle and elicits an inhibitory response that relaxes the contracting muscle. This is a safety mechanism that reduces the risk of injury; however, it also reduces force production. Typically within the first few weeks of regular training the body adapts and inhibits this safety mechanism. Long term training results in many other adaptions to enhance strength.
Most importantly enhancing strength is improving recruitment of muscle tissue and decreasing any inhibitory responses such as autogenic inhibition as mentioned before.
Understanding the Muscle Fiber
Now for recruitment we need to understand the muscle fiber itself. Each muscle fiber is controlled by a motor unit typically we define motor units as type I and type II. Muscle fiber type has to do with the motor unit innervating the muscle fiber.
For example all type II muscle fibers are innervated by a type II motor unit. This is commonly confused. Type II units are best stimulated with high intensity, meaning heavier weight. Heavy weight must be lifted in order to recruit and stimulate these motor units. Chronic stimulus of these units and fibers result in many adaptations to enhance strength. Chronic stimulus results in enhanced recruitment patterns, the firing of each motor neuron becomes more efficient with stimulus over time.
Chronic stimulus increases the size of the muscle as well; specifically there is a net accretion in actin and myosin within the muscle cell these are contractile proteins, more contractile proteins result in enhanced contraction due to an increase in the potential surface area of contractile proteins within each fiber. This means hypertrophy is still important for becoming stronger; a larger muscle is potentially a stronger muscle.
The one thing that has yet to be determined or discovered is muscular hyperplasia; in the human body hyperplasia refers to an increase in the number of cells. This phenomenon has been seen in animals, but has yet to be discovered in human beings.
The most important take home message is becoming stronger takes time – it is a chronic adaptation that you will only experience if you keep at it. Furthermore, scientific study tells us that the most important motor units for strength are not recruited unless they are stimulated. This means you must lift heavy enough and often enough to become strong and don’t forget recovery is important too.