I know you’ve been on the edge of your seat waiting for the next part to posted. Well, here it is.
We’ve discussed how important muscle mass is for daily life and how it supports you during disease. Now let’s examine its benefits for longevity. I would wager that you’re interested to find out how to make your life longer and more pleasurable.
Muscle and Osteoporosis
Milk does a body good. Pass it on.
Nah, you’re better off just passing on it. The dairy discussion is one for a different blog post, but if you still rely on milk for calcium and strong bones, there’s a much better option.
External force on bone is essential for modeling and re-modeling, processes that increase bone strength and mass. Although bodyweight and weight-bearing exercises provide some mechanical force on bones, the largest voluntary loads on bone come from muscle contractions (6). Correlations between grip strength and bone area, bone mineral content, and bone mineral density in both healthy athletes and stroke patients support the notion that muscle contractions play a significant role in bone strength and mass (7).
And what creates loaded muscle contractions? That’s right – pumping iron.
Skeletal muscle mass was correlated positively with bone mineral content and bone mineral density in a study of osteoporosis in men. Men with the least muscle mass also had increased risks of falls due to impaired static and dynamic balance. Thus, maintenance of adequate bone strength and density with aging is highly dependent on the maintenance of adequate muscle mass and function (8).
Muscle for Structural Integrity
If my spider-sense is correct, you are impressed with my research but still don’t see how it relates to you. Especially if you don’t have a critical illness or trauma.
Maybe not right now. But what if something does happen? In the last couple years I have personally coached two clients that have had near-death situations. They were both going about their daily lives, and in freak accidents they experienced physical traumas that put them inches from death. During their recovery, they both said the exact same thing to me: “I know 100% that if I had not been doing strength training this past year, I would be dead.”
If you haven’t guessed by now, the two most beneficial approaches to maintaining or increasing muscle mass and function are resistance exercise and nutrition.
Ladies, none of this means you have to look like a bodybuilder. That is a competitive sport that requires work way beyond a basic strength training program. Before you blurt out the seven words* that are like nails on a chalkboard to me, Google “Yeah She Lifts.” If you don’t find images of shoulders, abs, or butts that you envy, then you’re probably in need of a therapist not a trainer.
* “But I don’t want to get bulky.”
Improved muscle function not only allows for greater contractile properties (which we just learned leads to stronger bones), but also for greater metabolism. It improves insulin sensitivity, increases your resting metabolic rate, and oxidizes fat more efficiently. Increased metabolism + increased fat oxidation = beach body.
Resistance exercise can also prevent the onset of sarcopenia (degenerative muscle loss) later in life. Progressive loss of muscle mass and strength occurs throughout adult life, and in middle age the rate of loss is accelerated and maintained until old age. Intervention in middle age or younger ages is therefore necessary to offset the deleterious effects of sarcopenia in old age (9).
The desired result should be improved muscle mass, strength, and metabolic function, as opposed to traditional measures of exercise training, such as the maximal oxygen consumption, which have little direct relation to health outcomes (10). This means prioritize your training for muscle-building, not cardio. There’s a time and place for it, but that’s a different blog post.
Flesh builds flesh. Your body’s muscle protein is directly affected by protein intake in the diet. High dietary protein intakes increase protein synthesis by increasing systemic amino acid availability. The amino acids stimulate the synthesis of muscle (11). That’s just a fancy way of saying “eat more meat.”
Need a few more reasons?
Children given high protein intakes grow faster and have greater muscle mass (12).
Both muscle mass and strength are improved by increased availability of amino acids, even in the complete absence of activity in healthy young subjects confined to bed rest (13).
Studies show improved physical function of elderly individuals that increase their protein intake.
Insulin sensitivity is improved by eating more protein.
It tastes better than tofurkey (not scientifically proven, but still true).
Dietary recommendations in the United States have relied on epidemiologic studies with too many confounding variables to be accurate. If you’re looking for a range, an effective target is 0.8-1.0 grams of protein per pound of bodyweight. So, if you weigh 150, that’s 136-150g per day (about one and half pounds). Aim for the lower end if you’re just trying to maintain mass. Aim for the higher end or above if you’re trying to add mass. You can always err on the high side. Detrimental effects of protein intakes greater than that have not been documented (14).
Hopefully the theme of “lift, eat, repeat” was redundant enough in this post to sink in. It’s not only about looking and feeling better right now. It’s about laying the foundation for your health in the decades to come.
6. Frost HM. On our age-related bone loss: Insights from a new paradigm. J Bone Miner Res 1997;12:1–9.
7. Ducher G, Jaffre C, Arlettaz A, Benhamou CL, Courteix D. Effects of long-term tennis playing on the muscle-bone relationship in the domi- nant and nondominant forearms. Can J Appl Physiol 2005;30:3–17.
8. Szulc P, Beck TJ, Marchand F, Delmas PD. Low skeletal muscle mass is associated with poor structural parameters of bone and impaired balance in elderly men—the MINOS study. J Bone Miner Res 2005;20:721–9
9. Balagopal P, Royackers OE, Adey DB, Nair KS. Effects of aging on in vivo synthesis of skeletal muscle myosin heavy-chain and sarcoplasmic proteins in humans. Am J Physiol Endocrinol Metab 1997;273:E790– 800
10. Wolfe R. The Underappreciated Role of Muscle in Health and Disease. AJCN 2013; 479
11. Motil KJ, Matthews DE, Bier DM, Burke JF, Munro HN, Young VR. Whole-body leucine and lysine metabolism: response to dietary protein intake in young men. Am J Physiol Endocrinol Metab 1981;240:E712– 21
12. Hoppe C, Molgaard C, Thomsen BL, Juul A, Michaelsen KF. Protein intake at 9 mo of age is associated with body size but not with body fat in 10-y-old Danish children. Am J Clin Nutr 2004;79:494 –501.
13. Paddon-Jones D, Sheffield-Moore M, Urban RJ, et al. Essential amino acid and carbohydrate supplementation ameliorates muscle protein loss during 28 days bedrest. J Clin Endocrinol Metab 2004;89:4351– 8.
14. Dietaryreferenceintakesforenergy,carbohydrate,fiber,fat,fattyacids, cholesterol, protein, and amino acids (macronutrients). Protein and amino acids. Institute of Medicine, Food and Nutrition Board. Internet: http://www.nap.edu/books/0309085373/html/ 2002 (accessed 19 June 2006).