A "healthy" person will lose over 7kgs of muscle and replace it with at least 15kgs of body fat during their adult life.
As adults, with every passing decade, we lose the ability to preserve muscle mass. An ever-increasing amount of research suggests, this age-related decline in muscle underlines many of the undesirable conditions we associate with “getting old”, such as osteoporosis, Type-2 diabetes and cardiovascular disease.
If you are already overweight, you’re probably losing muscle even faster.
So how could your muscles have anything to do with avoiding diabetes or a heart attack?
Muscle tissue is the primary site of energy (ATP) turnover and therefore, the prime determinant of metabolic rate (which for most of us is the largest single contributor to daily energy expenditure). Muscle tissue is not only important for maintenance of a healthy weight by virtue of it’s mass and mitochondrial content; it is also, by far the largest site of lipid oxidation (fat burning) and glucose disposal (blood glucose control).
Bottom line; losing muscle changes your capacity to burn fat which is reflected by your blood lipid profiles. Also, your ability to metabolize carbs, which is reflected by poor blood glucose control.
From a functional perspective, by the time a person reaches 40 years of age they will have lost 50% of the strength they possessed in their 20s. By age 60, this decline will be as high as 70%.
Many of us may not care that we can’t bench press as much as we did in our 20s. However, functional strength and mobility go hand in hand. So does that 70% decline in strength and the incidence of hip/leg fractures from falls.
Another alarming stat is the high morbidity rate (60%) of healthy people over 70 suffering a hip/leg fracture.
The economic burden these conditions place on our healthcare system is enormous; costs are estimated to be in the billions of dollars every year....
The good news is, the premature onset of these conditions is totally preventable and often reversible.
Here’s your research-based prescription to protect yourself:
Lift weights, 30 minutes, 2x times a week! 
Protein after workouts will enhance the effect! 
Fish oil helps aging muscles too! 
What type of resistance exercise is best? Despite all the latest, amazing medical advances we’ve seen, nothing builds and preserves muscle as effectively as pumping iron - hoisting the ol' fashioned barbells 'n' dumbbells.
Just 30 mins a couple of times a week? Sure, you can do more if you want. But if you also perform other activities, two is a great start - its what Shar and I still do. If you'd like to offset the perils that rob us of our youth, vitality and ability to do more of what we love, there’s your prescription.
Like to learn more? See my full article on Muscle Mass Matters
 New Activity Guidelines Australia.
 Cribb PJ. Hayes A. Effect of whey protein isolate on strength, body composition and muscle hypertrophy during resistance training. Curr Opin Clin Nutr Metab Care. 2008 Jan;11(1):40-4.
 Kamolrat T, Gray SR, Thivierge MC. Fish oil positively regulates anabolic signalling alongside an increase in whole-body gluconeogenesis in ageing skeletal muscle. Eur J Nutr. 2013 Mar;52(2):647-57.