If you want to pack on lean muscle, you need to take a scientific approach to training. I’ve spent the better part of my professional career researching the complexities of muscle hypertrophy and applying the information gleaned to help numerous competitive physique athletes and recreational lifters alike optimize body composition. My new book, The MAX Muscle Plan, is the culmination of these efforts.
Several years ago, I published a review article in the Journal of Strength and Conditioning Research that outlined the three primary mechanisms involved in exercise-related muscle growth: muscle tension, muscle damage and metabolic stress. Here’s a brief synopsis of each of these factors.
Muscle Tension: Tension exerted on muscles during resistance exercise is generally considered the most important factor in muscle development. It is believed that the tension from lifting weights disturbs the integrity of working muscles, bringing about a phenomenon called mechanotransduction. Simply stated, mechanotransduction is the conversion of tension on muscle fibers into chemical signals that “turn on” anabolic pathways. Up to a certain point, greater muscular tension leads to a greater anabolic stimulus— a classic case of adaptation. However, it is believed that an upper limit exists beyond which there is a diminishing effect of high-tension levels on muscle growth. Once this threshold is reached, other factors become increasingly more important in the growth process. This is why bodybuilders generally display superior muscle growth compared to powerlifters despite the fact that bodybuilders routinely train with lighter weights.
Muscle Damage: Anyone who lifts weights has undoubtedly experienced feeling achy and sore following an intense exercise session. This phenomenon, called delayed-onset muscle soreness (DOMS), generally manifests approximately 24 hours following an intense workout with peak effects seen after about two to three days post-exercise. DOMS is caused by localized damage to muscle tissue, manifesting from small microtears in both the contractile proteins and surface membrane (i.e., sarcolemma) of the working muscles. The response to muscle damage can be likened to the acute inflammatory response to infection. Once damage is perceived by the body, immune cells (i.e., neutrophils, macrophages, etc.) migrate to the damaged tissue in order to remove cellular debris to help maintain the fiber’s ultrastructure. In the process, signaling molecules called cytokines are produced that activate the release of growth factors involved in muscle development. In this roundabout way, localized inflammation leads to a growth response that, in effect, strengthens the ability of muscle tissue to withstand future muscle damage.
Metabolic Stress: Perhaps the most intriguing factor associated with muscle development is exercise-induced metabolic stress. Research on patients confined to bed rest shows that metabolic stress induced by the application of a pressure cuff can help to attenuate muscle wasting, even in the absence of exercise. Other studies have found that pressure-cuff exercise performed with very light weights— far less than what is normally considered to be sufficient for promoting muscular adaptations— can promote significant muscle growth as a result of generating a substantial amount of metabolic stress. The muscle-building effects of metabolic stress can be attributed to the production of byproducts of metabolism called metabolites. These small fragments (including lactate, hydrogen ion, inorganic phosphate, creatine and others) are believed to indirectly regulate cell signaling. Various strategies using traditional training methods can be employed to enhance metabolic stress and therefore the growth response.
It’s important to understand that muscle tension, muscle damage, and metabolic stress generally do not exist in isolation of one another. Rather, they work synergistically, combining to produce an additive effect on building lean muscle. Only by achieving an optimal mix of these factors in your training routine can you maximize muscle development.
This concept forms the basis of The MAX Muscle Plan.