Although Sarcoplasmic hypertrophy and Myofibrillar hypertrophy can never becompletely separated, an individual can focus training on one over another. The theorybehind Sarcoplasmic hypertrophy is that by forcing the muscle fibers to exert force to acertain level of exhaustion, it conditions the body to compel the muscles to increase thestorage of necessary nutrients in order to maintain the required levels of energy to sustainthe needed levels of force. Increases in stored levels of glycogen, ATP, Calcium, CHOs,CP, etc., lends to the increase in the size of the Sarcomere, without a correspondingincrease in contractile proteins. Sarcoplasmic hypertrophy also alters the osmotic gradientacross the cell, that is, fluid flows into the cell to reestablish it. In turn, the cells swell,thereby increasing total muscle size.One of the most productive means to induce Sarcoplasmic hypertrophy is eccentrictraining. It is known that if the same force is exerted during the concentric phase of thelift as in the eccentric phase, fewer muscle fibers are activated while the musclelengthens. Because of this, eccentric contractions allow greater overall force productionin addition to less fiber recruitment, which means the fibers are stressed more.Because of this difference in fiber activation and utilization, a typical pyramid loadingmethod may not be the most effective in the development of muscle. The torquegenerated by the eccentric load is greater than during the concentric contraction. Inregards to typical resistance training, both types of contractions are involved, and,therefore, the concentric contraction limits the performance of the muscle; hence theamount of load that can be used is also limited. Similarly, since the intensity of exerciseis reliant on the magnitude of the load relative to maximum capabilities, it is logical toassume that the concentric phase is the variable that experiences the greater stress, andtherefore the greater adaptation (Hortobagyi and Katch 1990).Eccentric contractions are generally believed to induce greater gains by providing agreater training stimulus because there are greater forces associated with them. This factmay lead someone to believe that training eccentrically exclusively would be the bestchoice for the best gains. This, however, is not the total case. The size of the forcerelative to the maximum is what determines training stimulus, not the absolute force.Many studies show that concentric-only and eccentric-only programs yield similar gainsin strength and work capacity. It seems that programs that include both provide thegreatest results, rather than programs that are exclusive of one or the other (Dudley, et al1991; Colliander and Tesch 1990; Godard, et al 1998). Alternatively, some studies haveshown that an increase in peak torque in a concentric/eccentric exercise is greater aftertraining with eccentric-only contractions (Higbie, et al 1996). These seeminglycontradictive characteristics of eccentric contractions can be attributed to the followingcharacteristics:1. Cross-Bridge Activity: The high amount of stresses associate with eccentric trainingmay actually lead to a mechanical disruption of the chemical actin/myosin bond incontrast to the systematic binding of ATP. Because there are less total number ofcontractile proteins during eccentric movements, as well as the amount of overlappingamong sarcomeres, the maximum force that each sarcomere can exert varies along the
length of a muscle. Therefore, each sarcomere is stretched and then popped as it reachesits stress limit during the lengthening of a muscle, that is, the eccentric motion (Morgan1990; Morgan and Allen 1999).2. Motor Unit Activity: Synchronization among motor units is increased during eccentricmovements, and the proportion of common input to pairs of motor units is greater as well(Semmler, et al 2000).3. Maximality of Activation: Muscle force is greater during a voluntary eccentric phase;however, EMG is substantially less than during concentric. This implies that anindividual is unable to maximally activate a muscle during an eccentric phase (Higbie, etal 1996; Nakazawa, et al 1993; Kellis and Baltzopoulos 1998; Pasquet, et al 2000; Tesch,et al 1990; Webber and Kriellaars 1997; Westing, et al 1991).4. Hypertrophy: Eccentric movements may be a more effective stimulus for hypertrophy,which might be mediated by a differential control (transcription verses translation) ofprotein synthesis (Booth and Baldwin 1996; Williams and Neufer 1996; Wong and Booth1990).We can see by this research that an effective training method could be developed asfollowed: In order to facilitate intracellular fluid depletion, total volume is moreimportant than volume per set. In a concentric/eccentric movement, the load should beabout 80% 1RM, and 60-80 total reps per body part. Remember, we are not going forcomplete and total failure of the muscle tissue.After this, it is necessary to condition the body to increase the levels of intracellular fluidstorage by increasing the demand of these substrates, as mentioned before. This is donewith an eccentric-only phase; the load for this segment should be about 100-140% 1RM,and reps should stay between 3-5 reps per set.This type of training, however, can be very intense, and serious injury can result if it isnot done properly by an experienced lifter with a coach or a reliable training partnerpresent. Also, proper diet and nutrition is of vital importance if an athlete is to increaseand maintain the levels of the intracellular substrates, thereby increasing and maintainingthe size of the sarcomeres.