Building Muscle Without Exercise

While many people struggle with losing weight, some of us need to gain weight in order to improve our health. You may be dealing with, or recovering from, a chronic condition, such as those from years of gluten-induced damage like myself, or may want to avoid or reverse frailty caused by aging. Particularly for those who are severely damaged and cannot exercise too much, or if you are like me and are very insecure about being underweight (and are just beginning to put something together to do at home), you might be interested in whether or not building muscle without much exercise is possible.

Typical protein sources.

Fortunately, a study published in JAMA in 2012 suggests that building muscle without much additional exercise is possible. The purpose of this study was to evaluate the effects of different high-energy diets: one with low protein (5% of energy), one with normal protein content (15%) and one with high protein (25%). It involved 25 male and female participants, all with a BMI in the normal or overweight range. For 13-25 days, all participants were put on a weight-stabilising diet, and then for the next eight weeks were then put on one of the three excessive-energy diets as described above. These provided about a 40% increased energy intake compared to the stabilising diets. After the eight weeks, those on the low-protein diet gained just over 3kg, while those on the normal or high-protein diets gained just over 6kg. However, while resting energy expenditure and body protein/lean mass did not increase for the low-protein group, those on the normal protein diet gained 2.87kg of muscle, and those on the high-protein diet gained 3.18kg, and both increased their energy expenditure. With the low-protein diet, 90% of weight gain was fat, while in the other groups fat accounted for 50% of weight gain. Neither sex nor race significantly affected weight gain.

As the participants of this study still gained fat, I would still recommend exercising in order to build muscle; this just shows that you don't have to solely rely on exercise. The type of protein also matters too, i.e. the amino acids, which are the building blocks of proteins. There are around 20 amino acids, but the three branched-chain amino acids are most important for muscle growth, especially leucine. Leucine works with insulin and insulin-like growth factor 1 (IGF-1) to regulate muscle growth, partly by increasing the activity of mTOR, which often carries a negative image. However, mTOR has its place, in the context of building muscle, especially if you need to do this in order to avoid frailty. Additionally, even though I have written in support of lowering IGF-1 through the Paleo Diet, I have also said that increasing it is necessary to speed fracture healing. Context is key, just as you need some cortisol to live. I would also like to add the importance of glutamine, if you have considerably aged biologically or have/had another condition that results in gastrointestinal damage, as we often recommend this to rebuild the gut lining. The contribution of inflammation to age-related muscle loss is another topic for another post; that would be chronic inflammation, not the acute inflammation we often need to fight infection or initiate healing. Antiaging and longevity require control of various factors, not an all-or-nothing approach.