The task of gaining muscle can be a long and sometimes frustrating road. There seems to be a number of influences that make it a rocky road as well – a series of plateaus and breakthroughs that dot the landscape.
How much muscle can someone reasonably expect to be able to gain in a given period of time, and what are the influences that moderate the ability to gain muscle?
When we place a load or demand on skeletal muscle it will respond, given enough nutrition and rest, and consequently grow in density, and/or, size. When one is trying to build size or density the aim is to do some kind of resistance training that stimulates muscle growth.
There are a number of factors that regulate how fast and how much your muscles will grow. One of the major factors appears to be genetics and muscle fibre types. Muscles contain two main types of fibre – slow twitch (ST) and fast twitch (FT). ST fibres use oxygen, and contract more slowly and with less force than FT fibres, but have greater resistance to fatigue. ST fibres are great for running long distances but not for lifting heavy weights. FT fibres produce large amounts of force in the absence of oxygen and grow in density and cross-sectional area much more than ST fibres.
Each muscle in the body has a different proportion of ST and FT fibre. In addition, people vary in their overall ST:FT fibre ratio.
If someone had a higher FT fibre count, one would expect that they would potentially be able to attain more gross muscle growth.
Another factor at play is the amount of testosterone available. Just as with fibre types, people have different natural testosterone levels. Women have much smaller levels than men and therefore aren’t as muscular. Testosterone levels also decrease with age, and appear to be affected somewhat by stress and sleep.
Nutrition plays a rather large role in muscle growth. This field is very large and complex, so I would just mention that according to registered dieticians eating a wide variety of healthy foods with adequate protein for training is all that is required for most people.
But a note of caution as some people tend to overeat. The most protein that the body can make use of, as research has repeatedly shown, is around 2 grams of protein eaten for each kilogram of body weight. Anything over this amount is simply excreted or stored as body fat.
The final major factor that influences muscle gain is your current fitness level and experience with weight lifting. Paradoxically, less fit novices to weight lifting will gain more muscle, more quickly (assuming optimal fibre ratios, testosterone and nutrition) than a fit, experienced, well-muscled individual. This does make sense when you consider that as you reach your genetic maximum, any gains you could make would tend to be smaller. It’s a process of diminishing returns. It appears that the greatest amount of muscle gain is roughly 2 pounds per month for an novice, younger male. As we age, grow some muscle and get more experience with lifting, the slower the gains in growth become. And women should expect about half the gain in muscle weight because of the differences in testosterone levels.
(Kerry Senchyna is the founder, owner and president of West Coast Kinesiology since 1992 and is a provincially registered kinesiologist (BCAK). He provides active injury rehabilitation, ergonomic assessments as well as elite athletic conditioning programs for clients.)